The Energy Frontier of Combining Coal and Renewable Energy Systems Stephen Mills Senior Consultant the OFFICIAL JOURNAL of WORLD COAL INDUSTRY IEA Clean Coal Centre

WINTER 2014 CORNERSTONE

VOLUME 2 ISSUE 4 THE OFFICIAL JOURNAL OF THE WORLD COAL INDUSTRY The Energy Frontier of Combining Coal and Renewable Energy Systems Stephen Mills Senior Consultant THE OFFICIAL JOURNAL OF WORLD COAL INDUSTRY IEA Clean Coal Centre

WINTER 2014 • VOLUME 2, ISSUE 4

Developing Country The Flexibility of German Exploring the Status Needs Are Critical to a Coal-Fired Power Plants of Oxy-fuel Technology Global Climate Agreement Amid Increased Renewables Globally and in China Our mission is to defend and grow markets for coal based on its contribution to a higher quality of life globally, and to demonstrate and gain acceptance that coal plays a fundamental 1 role in achieving the least cost path to a sustainable low carbon and secure energy future.

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WCA_advert_h273 x w206mm 27 Nov 2014.indd 1 27/11/2014 13:30 FROM THE EDITOR Finding Common Ground

enewables and coal are the two fastest growing forms of energy today. The growth of these energy sources is particularly prominent in developing Rcountries, where most expansion in electricity capacity is occurring. Coal and renewables often require less upfront investment, less infrastructure, and are more widely distributed globally than other energy options, making them ideal choices for regions that need to add electricity capacity in the near term.

Coal and renewable energy systems can be integrated in such a way that the advantages of each energy source can be more fully harnessed. For instance, coal and biomass cofiring and cogasification, the most widespread combinations practiced today, allow for larger, more cost-effective plants than would be possible with only biomass, but a smaller carbon footprint than would be possible using coal without carbon capture, utilization, and storage (CCUS). In fact, there are many more examples of optimized systems in which renewable and coal energy systems could be optimally integrated.

The main issues facing increased integration of coal and renewable energy systems are not technical. Instead, they are generally institutional. Advocates for such integration are few and far between. However, some of the advantages are worth consideration: Integration can produce more power than a standalone renewable Holly Krutka plant and can be an enabling technology to get high-cost renewables, such as uncon- Executive Editor, Cornerstone ventional geothermal and concentrated solar power, deployed in the near term. Yet such projects are generally not included under renewable portfolio standards or clean energy standards. In addition, negative net greenhouse gas emissions, which can be achieved through cofiring coal and biomass with CCS, are often not recognized by emissions trading schemes.

The deployment of renewables is already changing the operation of coal-fired power plants; tomorrow’s plants will need to be smarter and more responsive than those of the past. As is being demonstrated by Germany’s fleet of coal-fired power plants, rapid turndown to 25–40% of full capacity as well as rapid ramping is now not just possible, but has become standard operating procedure.

Recently, low-carbon energy production from coal took a major step forward with the commencement of operation of SaskPower’s Boundary Dam project. This monumental CCUS project is now demonstrating that low-carbon coal is within our grasp. As coal and renewables grow globally, improved integration and efficiency as well as deployment of CCUS can ensure that coal and renewables can both contribute to decreasing the carbon footprint of the energy sector without sacrificing reliability, energy security, and eventually cost. Further demonstration, development, and deployment will be necessary to reduce costs, which emphasizes why increased integration of coal and renewables must find support within the global energy discussion today.

This issue of Cornerstone offers a wide range of articles that discuss the many areas in which coal and renewables do and could intersect. On behalf of the editorial team, I hope you enjoy it.

www.cornerstonemag.net 1 CONTENTS

FROM THE EDITOR Finding Common Ground 1 Holly Krutka, Cornerstone

VOICES The Rise of Electricity: Offering Longevity, 11 Improved Living Standards, and a Healthier Planet Frank Clemente, Penn State University 11 ENERGY POLICY Understanding the National Enhanced Oil Recovery Initiative 17 Patrick Falwell, Center for Climate and Energy Solutions Brad Crabtree, Great Plains Institute

Developing Country Needs Are Critical 21 to a Global Climate Agreement Benjamin Sporton, World Coal Association

STRATEGIC ANALYSIS The Flexibility of German Coal-Fired 21 25 Power Plants Amid Increased Renewables Hans-Wilhelm Schiffer, World Energy Council

Toward Carbon-Negative Power Plants 31 With Biomass Cofiring and CCS Janne Kärki, Antti Arasto,VTT Technical Research Centre of Finland

Evolution of Cleaner Solid Fuel Combustion 36 Christopher Long, Peter Valberg, Gradient

4 Cover Story The Energy Frontier of Combining Coal and Renewable Energy Systems Stephen Mills The global demand for energy continues to increase—as the fastest growing sources of energy, coal and renewables are largely responsible for meeting that demand. A Senior Consultant at the IEA Clean Coal Centre explores the projections for coal and renewable deployment as well as opportunities for optimization.

2 TECHNOLOGY FRONTIERS Making Coal Flexible: Getting From Baseload to Peaking Plant 41 Jaquelin Cochran, National Renewable Energy Laboratory Debra Lew, Independent Consultant Nikhil Kumar, Intertek

Geothermal Assisted Power Generation for Thermal Power Plants 46 41 Nigel Bean, Josephine Varney, University of Adelaide Shenhua’s Development of Digital Mines Han Jianguo, Shenhua Group Co., Ltd 51

Direct Carbon Fuel Cells: An Ultra-Low Emission Technology for Power Generation 56 Christopher Munnings, Sarbjit Giddey, Sukhvinder Badwal, CSIRO Energy Flagship

Exploring the Status of Oxy-fuel Technology Globally and in China 61 Zheng Chuguang, 56 Huazhong University of Science and Technology and Clean Energy Research Center

GLOBAL NEWS Covering global business changes, publications, and meetings 67 LETTERS 71 VOLUME 2 AUTHOR INDEX 73 67

Chief Editor Copyright © 2014 World Coal Association Gu Dazhao, Katie Warrick Editorial Office Executive Editor Shenhua Science and Technology Research Holly Krutka, Liu Baowen Institute Co., Ltd 006 mailbox Official Journal of World Coal Industry Shenhua Science and Technology Park, Responsible Editor Future Science & Technology City, Chi Dongxun, Li Jingfeng Changping District Beijing 102211, China Copy Editor Li Xing, Chen Junqi, Zhang Fan Phone: +86 10 57336026 Sponsored by Shenhua Group Corporation Limited Fax: +86 10 57336014 Production and Layout John Wiley & Sons, Inc. Email: [email protected] (Chinese) Email: [email protected] (English) CORNERSTONE (print ISSN 2327-1043, Website: www.cornerstonemag.net online ISSN 2327-1051) is published four times a Published by John Wiley & Sons, Inc. year on behalf of the World Coal Association by The content in Cornerstone does not necessarily Wiley Periodicals Inc., a Wiley Company reflect the views of the World Coal Association or 111 River Street, Hoboken, NJ 07030-5774. its members.

www.cornerstonemag.net 3 COVER STORY The Energy Frontier

By Stephen Mills Senior Consultant “Although coal and renewable energy IEA Clean Coal Centre sources might appear to be strange bedfellows … we could see increased deployment of combinations of the world’s two fastest-growing energy sources becoming a reality.”

he world is undoubtedly hungry for energy and this natural gas, and coal will continue to be used widely, although hunger is growing. There are strong incentives to in some situations, the increasing use of renewable energy develop improved sources of energy. By 2040, the sources may reduce the amount of fossil fuels currently used. T 1 world’s population will have reached nearly nine billion. All Regardless, on a global basis, coal will continue to play a major of these people will need to be housed, fed, and have the opportunity to make a living; this inevitably means that much role. This will be particularly true in some of the emerging more energy is going to be needed. By 2040, global energy economies where growing industrialization and urbanization demand will be about a third greater than current levels.2 Oil, continue to relentlessly drive electricity demand upward.

4 of Combining Coal and Renewable Energy Systems

At the moment, over 1.2 billion people lack access to any electricity, and another two billion are considered to have inadequate access. A key goal of the 2010 Copenhagen Accord is to provide energy to these underserved populations. There may be few energy source options available—in some countries, coal is the only economically available bulk source capable of providing reliable energy. Although its use is set to decline in some developed economies, coal will continue to be used widely and in considerable quantities. For over a decade, global coal consumption has risen steadily; in some non-OECD countries, in particular, both production and consumption have increased dramatically. During this time, consumption has risen by nearly 60%, from 4.6 Gt in 2000 to about 7.8 Gt in Poland’s Belchatów coal-fired power station is Europe’s largest 2012.3 Despite efforts to diversify, coal remains vitally impor- thermal power plant (courtesy PGE Elektrownia Belchatów). tant for many economies. Since 2000, apart from renewables, it has been the fastest-growing global energy source. It’s the electricity. Global renewable power capacity continues to second source of primary energy after oil, and provides more increase. In 2013, hydropower and solar PV each accounted than 30% of global primary energy needs. for about 33% of new renewable capacity, followed by wind at about 29%.5 The biggest individual coal reserves are in the U.S., Russia, China, Australia, and India. In all of these countries, coal is Several driving forces support the growth in renewables. All used to generate large percentages of electricity. In several, it developed nations rely heavily on an adequate and -acces also provides important economic benefits as it is exported to sible supply of electricity and, for a long time, demand has other power-hungry economies. At the moment, coal’s princi- continued to rise in nearly every country. However, in recent pal use remains electricity generation; coal-fired power plants years, concerns over issues such as the depletion of energy produce 41–42% of the world’s electricity. In the coming resources and global climate change have been heightened. years, electricity will continue to be provided by many differ- The preferred response of many western governments has ent generating technologies, but the projected combinations been a supply-side strategy—namely, to raise the share of are highly site-specific. The IEA World Energy Outlook (2012) renewables (especially renewables other than hydropower) in suggests that, for the foreseeable future, power production the energy mix toward 20% and beyond. To date, wind power from most sources will continue to increase (Figure 1).4 In has emerged as the most competitive and widely deployed many countries, coal and renewable energy systems are being renewable energy, although levels of solar power are also deployed at greater percentages and, thus, there is increased growing steadily. Renewable energy technologies such as wind interest in how to optimally integrate these systems. In fact, and solar have obvious features that make their use attractive. there are a significant number of opportunities. 14k 12k Coal AN ODD PARTNERSHIP? Renewables 10k Gas With the ever-increasing use of all types of fossil fuels, there 8k has also been a marked increase in the uptake of renewable 6k energy sources. In many economies, these now represent a 4k Nuclear rapidly growing share of electricity supply; Table 1 shows the Power Global top regions and countries at the end of 2012. 2k Generation Mix (TWh) Oil In 2013 renewables made up more than 26% of global gen- 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035 erating capacity; in 2013 they produced 22% of the world’s FIGURE 1. Global power generation mix4

www.cornerstonemag.net 5 COVER STORY

TABLE 1. Global renewable electric power capacity5 (end 2013) (GW)

Technology World Total EU-28 BRICS China U.S. Germany Spain Italy India Bio-power 88 35 24 6.2 15.8 8.1 1 4 4.4 Geothermal 12 1 0.1 ~0 3.4 ~0 0 0.9 0 Tidal 0.5 0.2 ~0 ~0 ~0 0 ~0 0 0 Solar PV 139 80 21 19.9 12.1 36 5.6 17.6 2.2 CSP 3.4 2.3 0.1 ~0 0.9 ~0 2.3 ~0 0.1 Wind 318 117 115 91 61 34 23 8.6 20 Total RE power capacity* 560 235 162 118 93 78 32 31 27 Hydropower 1000 124 437 260 78 5.6 17.1 18.3 44 Total RE power capacity 1560 360 599 378 172 84 49 49 71

*Excludes hydropower. Note: BRICS = Brazil, Russia, India, China, and South Africa

Although initial capital costs for renewables-based systems forms may be subject to limited or seasonable availability, and can be high, operating costs can be low; emissions generated various pre-treatments may be needed. Inevitably, such chal- during day-to-day operation are effectively zero. lenges can add complexity and cost to energy production.

Especially in faster-growing energy markets, these renew- Co-utilization of coal and biomass need not be limited to co- able energy systems are not replacing existing or even new combustion in existing power plants—there are a number of coal-fired power plants. Renewables and coal-fired power other possibilities such as co-gasification. Coal gasification is generation are growing simultaneously. Therefore, it is worth a well-established versatile technology. Combining these two exploring the many options for combining these very different different feedstocks can be beneficial. For instance, facilities forms of energy in the most cost-effective, environmentally that co-gasify biomass in large coal gasifiers can achieve high conscious, and efficient means possible. A growing number of efficiencies and improve process economics through greater hybrid coal-renewables systems have been proposed or are economies of scale compared to a biomass-only facility. Such being developed around the world, several of which could a combination can also help reduce the impact of fluctuations offer significant potential. in biomass availability and its variable properties. Combining biomass and coal in this way can be useful, both environmen- Coal and Biomass tally and economically, as it may be possible to capitalize on the advantages of each feedstock, and overcome some of their Combining biomass with coal is a prime example of combining individual drawbacks. Biomass can have an impact on CO2 renewables and coal. Such a combination is already deployed emissions from a combustion or gasification process. Replacing fairly widely in the form of cofiring biomass in large conven- part of the coal feed with biomass (assuming that it has been tional coal-fired power plants. Around the world, a growing produced on a sustainable basis) can effectively reduce the number of power plants regularly replace a portion of their overall amount of CO2 emitted. Potentially, the addition of coal feed with suitably treated biomass. More than 150 coal- carbon capture and storage (CCS) technology could result in a fired power plants now have experience with cofiring biomass carbon-neutral or even carbon-negative process. Globally, con- or waste fuels, at least on a trial basis. There are ~40 pulver- siderable quantities of biomass are potentially available—in ized coal combustion (PCC) plants that cofire biomass ona many countries, biomass remains an underexploited resource. commercial basis, with an average of 3% energy input from biomass.6 Similar to many conventional coal-fired power plants, several commercial-scale, coal-fueled, integrated gasification com- Biomass comes in many forms and can be sourced from bined cycle (IGCC) plants in operation have at least trialed com- dedicated energy crops (such as switchgrass and miscanthus), bining biomass with their coal feed, and several proposed IGCC short-rotation timber, agricultural crops and wastes, or forestry projects aim to do the same. For instance, a planned IGCC and residues. When combined with coal, biomass can provide a chemicals production plant (with CCS) at Kędzierzyn in Poland number of advantages. However, its use on a large commercial will co-gasify coal and biomass.7 To date, useful operational scale could create a number of issues. For example, the vol- experience in co-gasifying has been gained with all major umes to be harvested and handled can be substantial, some gasifier variants (entrained flow, fluidized bed, and fixed bed

6 systems). Different types of coal have been co-gasified suc- Most major wind and solar facilities do not operate in isola- cessfully with a wide range of materials, many of which are tion. Generally, they feed electricity into existing power grids wastes that would have otherwise ended up in landfills or, at or networks. Often, such grids are fed by a variety of different least, created disposal problems. types of power plants—there may be various combinations of coal- and gas-fired power plants, some hydro, and possi- Co-utilizing coal and biomass is not limited to power gen- bly nuclear. The grid makeup and ratio between plant types eration. In a number of countries, hybrid concepts for the is never the same, as these factors differ from country to production of SNG, electricity and/or heat, and liquid trans- country based on the local circumstances. On the face of it, port fuels have either been proposed or are in the process the addition of a large amount of wind power into a grid, for of being developed or tested. Coal/biomass co-gasification example, is a positive development. However, a large input features in some of these. However, as well as incorporating from intermittent sources into existing power systems can biomass, some propose to take this a step further by adding upset grid stability and have major impacts, particularly on yet another element of renewable energy to the system, gen- how thermal power plants within the system operate. Many erally by incorporating electricity generated by intermittent coal- and gas-fired power plants no longer exclusively provide renewables (such as wind and solar power). baseload power, but are now required to operate on a more flexible basis. Many are increasingly switched off and on, or ramped up and down, much more frequently than they were Coal, Wind, Solar, and Geothermal designed to be. Inevitably, this is guaranteed to throw up a number of issues—significantly increasing wear and tear on Wind power has become the most widely deployed renewable plant components, reducing the operating efficiency of units energy. In 2013, global capacity hit a new high of 318 GW. In not designed for variable operation, and impairing the effec- that year, China alone installed more than 16 GW; by 2020, the tiveness of emission control systems. Ideally, such important IEA projects the country will more than double its wind power impacts should be taken into consideration and factored into capacity from the present level of 90 GW to around 200 GW.8 any energy-producing scheme, but this is particularly true in For comparison, the European Union countries have a com- cases where coupling intermittent renewables with conven- bined ~90 GW of installed capacity. In 2013, wind surpassed tional thermal power plants is being proposed. nuclear to become the number three source of energy after coal and hydropower in China.9 Reportedly, this is part of the Clearly, the most significant drawback with wind and solar greatest push for renewable energy that the world has ever power is their intermittency. Consequently, periods of peak seen.10 power output often do not correspond with periods of high

International Power’s 1-GW Rugeley power station in the UK. Like many others, this power plant has trialed cofiring various biomass materials with coal (courtesy Russell Mills Photography).

www.cornerstonemag.net 7 COVER STORY

Another ongoing project in Germany is expected to lead to significant improvements in the overall efficiency of the electrolysis process: E.On’s power-to-gas project at Falkenhagen. This technology utilizes multiple electrolyzers driven by excess electricity from a nearby wind farm to provide the power to produce hydrogen and oxygen. Output from the region’s wind farms frequently exceeds demand, so instead of taking the turbines offline when this happens, some of the electricity is now being fed to the electrolyzers. In this case, the hydrogen produced is being injected into the local natural gas grid, which acts as a large storage system. Effectively, it’s a clever way of storing renewable energy.

There is also an opportunity to integrate coal-fired power plants with renewable sources of thermal energy, such as geothermal or solar thermal. The benefit of this type of integrated hybrid system is that the renewable source of energy can take advantage of the existing infrastructure of the coal- fired power plant, such as the steam cycle, connection to the grid, and transformers. Generally, this makes the economics much more attractive compared to a stand-alone renewable plant. Obviously, the availability of the renewable resource at the coal-fired power plant site is a prerequisite for such hybrid systems to be successful.

Smøla wind farm in Norway (courtesy Statkraft) Hybrid thermal systems operate by using heat from renewable energy to increase the temperature of the coal-fired power electricity demand, and vice versa. At times, there can be plant boiler feedwater. This increases the efficiency of the significant amounts of surplus unwanted electricity available, power plant, effectively displacing some coal for renewable particularly from wind farms. This can be quite a widespread energy (or using the same amount of coal and producing more phenomenon, and the usual solution is to take wind turbines electricity). Such thermal hybrid projects may be the most offline. However, rather than “waste” this electricity, it would cost-effective option for large-scale use of solar thermal and be much more beneficial to find an effective means of using it. geothermal energy, although, to be employed, this approach One option is to use electricity not needed to fill demand to must be recognized under renewable energy incentives. In electrolyze water, producing hydrogen and oxygen. Both gases the future, there may also be an opportunity for renewable have the potential to be component parts of hybrid energy sources of energy to provide the thermal load required for systems and there are various schemes that propose feeding carbon capture and storage, thus significantly reducing the the hydrogen into syngas from gasification systems, use it in overall impact to the power plant and contributing to large- fuel cells or directly as a transport fuel, or combust it in gas scale reductions in greenhouse gas emissions. turbines to generate electricity.

Similarly, the oxygen could be used for a host of commercial and industrial applications, or fed to a coal/biomass gasifier or an oxy-fuel combustion plant to generate electricity. Different concepts and schemes combining gasification, intermittent renewables, and electrolysis are currently being examined. Some aim to incorporate carbon capture and storage. For example, an on-going project in Germany is combining coal- based power generation with aspects of carbon capture and wind-generated electricity with trials of advanced electrolyzer technology (to produce hydrogen and oxygen from water).11 Success could encourage increased uptake of, for instance, electrolysis, as a component part of various coal/renewables systems. Assuming that the economics can be made to work, E.On’s power-to-gas project at Falkenhagen in Germany several schemes look promising. (courtesy E.On)

8 Currently, around 15 hybrid solar thermal plants, including could also be incorporated into systems fueled by coal/bio- those on coal- and natural gas-fired power plants, are being mass combinations. developed, with a total capacity of 460 MW.12 Thermal hybrid projects based on unconventional geothermal resources are A number of projects are more advanced than others, with at an earlier stage of development and the field will require development programs well underway. Some components additional research prior to large-scale demonstrations.13 (such as co-gasification) have now been well established, and others are under development or being trialed (such as the commercial-scale demonstration of hydrogen production from CURRENT STATUS wind power and testing of advanced electrolyzers). A number of proposed hybrid systems show potential—although in the Some systems are at early stages in their development or near to medium term, assuming outstanding technical and have been undertaken at a very small size, hence extrapo- economic issues can be resolved fully, most seem likely to be lating to commercial scale and obtaining firm process costs applied initially to niche markets, or to find application under remains problematic. For a variety of reasons, not all of the specific, favorable circumstances. different schemes being considered appear to be technically and/or economically viable. However, some do appear to be more robust. On-going developments (in, for instance, gasifier CLOSING THOUGHTS and electrolyzer design) should improve cost competiveness. Where hydrogen and/or oxygen production forms part of Set against a background of growing global population and ris- a hybrid energy scheme, reductions in the cost of electric- ing energy demand, there is a pressing need to come up with ity provided by renewable energy sources (such as wind and new, cost-effective, clean, reliable energy systems. To help solar) would also be beneficial in making electrolysis more tackle this, many hybrid energy schemes have been proposed, cost effective. Some examples of on-going hybrid projects are some more practical than others. Despite efforts by many given in Table 2. Although some are currently focused only on countries to diversify their fuel mix, fossil fuels such as coal will biomass, potentially different elements from these processes continue to provide a significant part of the world’s energy for

TABLE 2. Examples of hybrid energy-producing systems proposed

Organization Technologies Proposed Status

Various studies underway: • combining wind power and biomass gasification Gasification/co-gasification + NREL, U.S. • combining biomass gasification and electrolysis electrolysis (wind) • combining coal and biomass co-gasification Several gasification-based hybrid systems being examined Systems to produce SNG, electricity, and biodiesel. Coal gasification + electrolysis NETL, U.S. 3000 t/d plant proposed. (wind) Unconverted coal from gasifier fed to oxy-fuel combustor Systems could be used to produce F-T chemicals, synfuels. CRL Energy, New Coal/biomass co-gasification + O fed to gasifier. H to enrich product gas, stored, or used as Zealand electrolysis (wind) 2 2 transport fuel or in fuel cells. Leighty Foundation, Coal/biomass co-gasification + O from electrolysis fed to gasifier U.S. electrolysis (wind) 2 Biomass (wood) gasifier + Univ. Lund, Sweden O from electrolysis fed to gasifier electrolysis (wind) 2 Various co-generation concepts to produce power, heat, and Elsam/DONG, Biomass gasification + transport fuels examined. Denmark electrolysis (wind, solar) H2 added to syngas. O2 used for biomass gasification Univ. Lausanne, Wood gasification + Several processes examined for SNG production Switzerland electrolysis Various: gasification + O from electrolysis fed to gasifier. H fed to syngas. China 2 2 electrolysis (wind) Mainly for SNG, methanol, ethylene glycol production

Note: SNG = synthetic natural gas; F-T = Fischer-Tropsch.

www.cornerstonemag.net 9 COVER STORY

REFERENCES

1. United Nations Population Division. (2014). Concise report on the world population situation 2014, www.un.org/en/develop ment/desa/population/publications/pdf/trends/Concise%20 Report%20on%20the%20World%20Population%20Situa tion%202014/en.pdf 2. International Energy Agency (IEA). (2012, 25 July). State of play: New IEA statistics publications highlight latest global and OECD trends across major energy sources, www.iea.org/newsrooman devents/news/2012/july/name,28615,en.html 3. IEA. (2014). Coal information, www.iea.org/w/bookshop/646- Coal_Information_2014 4. IEA. (2012). World energy outlook 2012, www.worldenergyout look.org/publications/weo-2012/ 5. Renewable Energy Policy Network for the 21st Century (REN21). (2014). Renewables 2014 global status report, www.ren21.net/ Portals/0/documents/Resources/GSR/2014/GSR2014_full%20 report_low%20res.pdf 6. Adams, D. (2013). Sustainability of biomass for cofiring. CCC/230. London: IEA Clean Coal Centre. www.iea-coal.org.uk/ documents/83254/8869/Sustainability-of-biomass-for-cofiring,- CCC/230 7. Cornot-Gandolphe, S. (2012, October). The European coal market: Will coal survive the EC’s energy and climate policies? Paris: Institut Français des Relations Internationals. 8. IEA. (2011). Technology roadmap: China wind energy development 2050. Available at: www.iea.org/publications/freepubli cations/publication/technology-roadmap-china-wind-energy- development-roadmap-2050.html 9. Yang, C. (2013). Wind power now No. 3 energy resource. People’s Daily English Edition, english.peopledaily.com.cn/90778/8109836. html Hybrid coal and renewable energy systems offer synergistic 10. Shukman, D. (2014, 8 January). China on world’s “biggest push” benefits. (photo courtesy of Russell Mills Photography) for wind power. British Broadcasting Corporation, www.bbc. co.uk/news/science-environment-25623400 the foreseeable future. For a number of reasons, where possi- 11. Farchmin, F. (2013, 6 November). Integration of regenerative en- ble, it makes sense to look at coupling coal use with renewable ergy into Power2Gas by PEM electrolyzer technology. CO2RRECT energy sources. Each power-producing system has its own pros Project. Smart Grid-Infotage 2013, Munich, Germany, www.in dustry.siemens.com/topics/global/en/pem-electrolyzer/silyzer/ and cons, but combining these different systems in creative Documents/2013-11-06_SMARTGRID_Munich_stick.pdf ways may offer the possibility of overcoming some of these 12. Electric Power Research Institute. (2012, April). Utility perspec- shortcomings. With this in mind, various energy production tive: Solar thermal hybrid projects. Clean Energy Regulatory concepts that propose combining a number of different tech- Forum, National Renewable Energy Laboratory, Golden, Colo- nologies with coal are being developed around the world. rado, U.S., www.cleanskies.org/wp-content/uploads/2012/04/ Libby_CERF3_04192012.pdf To be a practical proposition, as with all power-producing sys- 13. Bean, N., & Varney, J. (2014). Geothermal assisted power gen- tems, any hybrid scheme needs to be clean, workable, and eration for coal-fired power plants. Cornerstone, 2(4), 46–50. economically sound. Based on work carried out recently by 14. Mills, S.J. (2011). Integrating intermittent renewable energy the IEA Clean Coal Centre, some hybrid systems appear to be technologies with coal-fired power plants. CCC/189. London: viable and have potential.14,15 Although coal and renewable IEA Clean Coal Centre. energy sources might appear to be strange bedfellows, it’s 15. Mills, S.J. (2013). Combining renewable energy with coal. not unrealistic to suppose that in the coming years we could CCC/223. London: IEA Clean Coal Centre. see increased deployment of combinations of the world’s two fastest-growing energy sources becoming a reality. The author can be reached at [email protected]

10 VOICES

The Rise of Electricity: Offering Longevity, Improved Living Standards, and a Healthier Planet

By Frank Clemente medical care improved dramatically, and a vast system of elec- Professor Emeritus of Social Science and tronic communication emerged.2,3 Former Director of the Environmental Policy Center, Penn State University “Since 1970, the global demand for n 1972, The United Nations’ Stockholm Conference on the electricity has more than quadrupled Human Environment issued the following Declaration: “Both Iaspects of man’s environment, the natural and the man- ... with ~42% of this incremental made, are essential to his well-being and to the enjoyment of basic human rights, the right to life itself.”1 In other words, demand being met by coal.” people are part of the environment too. The Stockholm Declaration stressed that vast numbers of people continue to live far below the minimum conditions required for a decent Electricity supports quality of life increases, economic well- human existence, deprived of adequate food and clothing, being, and a clean environment. Electricity is highly unique shelter and education, health and sanitation. The Conference compared to other forms of energy: concluded that economic and social development are essential for ensuring a favorable living and working environment • Flexible—convertible to virtually any energy service—light, for humans and for creating conditions on earth that are nec- motion, heat, electronics, and chemical potential essary for the improvement of the quality of life. • Permits previously unattainable precision, control, and speed • Provides temperature and energy density far greater than Electricity is the foundation of such development and is the those attainable from standard fuels lifeblood of modern society. The U.S. National Academy of • Does not require a buildup of inertia—offering instanta- Engineering identified societal electrification as the “greatest neous access to energy at the point of use engineering achievement” of the 20th century, during which the global population grew by overfour billion people, the rise Although it may seem counterintuitive to some, electrifi- of the metropolis occurred, transportation was revolutionized, cation offers tremendous environmental benefits. Electro-

New power lines providing access to electricity allow for energy to be utilized with increasing efficiency.

www.cornerstonemag.net 11 VOICES

technologies are more efficient than their fuel-burning coun- will move to, ever-growing cities. Urbanization may offer the terparts and, unlike traditional fuels burned by the user, no chance to lift oneself out of poverty, but the electricity must waste and emissions evolve at the point of use—no smoke, be available to support the business and industries that can ash, combustion gas, noise, or odor. Clearly, it’s important that provide much-needed opportunities. there are emissions controls in place when electricity is generated; controlling criteria emissions (e.g., particulate matter, THE DISPARITY OF ELECTRIFICATION SOx, NOx, mercury) at the source of large-scale electricity generation is possible using commercially available technologies. Figure 1 provides a comparison of the UN’s Human Develop- In addition, electrification increases the efficiency of society’s ment Index (HDI) and the per capita electricity utilization of primary energy consumption and, therefore, reduces the many nations. Note that the major aspects of the HDI, such as energy intensity of greenhouse gas emissions. Carbon capture life expectancy, educational attainment, and per capita GDP, and storage (CCS) technologies are also being developed that are statistically related to increased access and utilization of will allow for the carbon footprint of fossil fuel-based sources electricity. of electricity to be dramatically reduced.

Given these beneficial attributes of electric power, it is not surprising that demand continues to increase. Since 1970, the global “Urbanization may offer the chance demand for electricity has more than quadrupled from approximately 5200 TWh to almost 23,000 TWh, with ~42% of this to lift oneself out of poverty, but incremental demand being met by coal, which is why this fuel source has been referred to as the cornerstone of global power.4 the electricity must be available to

Despite the staggering past growth of electricity demand, support the business and industries the future world will require far greater amounts of power. The Current Policies scenario in the IEA’s 2013 World Energy that can provide much-needed Outlook projected a 80% increase in power generation between 2011 and 2035.4 However, the center of that pro- opportunities.” jected incremental growth reflects a global shift; from 1980 to 2000, almost a quarter of the global increase in generation came from the U.S., Japan, and Europe. Over the next 20 The Copenhagen Accord of 2009 concluded that “economic years, these developed nations will be relatively minor players and social development and poverty eradication are the first in growth, while developing Asia will account for over 60% of and overriding priorities of developing country Parties.”7 new generation, led by China, where the increase alone will Energy, particularly electricity, is the pathway to achieving be about 6500 TWh—or about twice the current output of the these goals. More than 1.3 billion people have no electricity EU. Coal will be the mainstay of the next generation as well, at all and billions more have inadequate access to power.4 accounting for over 40% of electricity in 2035.4 Electricity deprivation in the developing world takes a mighty toll. The impact on children and women is stark: According to The empirical realities of at least three societal trends demon- the UN, about 17,000 children die each day from causes that strate the magnitude of the emerging need for major increases are preventable with sufficient electricity, including access to in electricity generation:

1. Economic growth 1 Germany Japan U.S. 2. Population increase 0.9 3. Urbanization 0.8 Brazil Russia 0.7 The projections are staggering. By 2050, the global economy China is projected to quadruple to US$280 trillion in real terms. At 0.6 India least 80% of this increase will be in the developing world, and 0.5 Nigeria many of these nations will depend on coal to advance their 0.4 Human Development Index Development Human economies. By 2050, the world will add 2.4 billion people—67 0.3 million every year or 184,000 every day.5 In essence, the 0 2000 4000 6000 8000 10,000 12,000 14,000 16,000 entire population of Rome is added to the global rolls every Electricity Use per Capita per Year (kWh) two weeks. Most of these people will either be born in, or FIGURE 1. Human Development Index versus electricity use6

12 clean water, better sanitation, adequate food, medicine, and Sub-Saharan Africa, a region with a population of more than more education to improve earning power—all things that 900 million people, uses less electricity per year (145 TWh) can be taken for granted in the developed West.8 At least 1.5 than the U.S. state of Alabama (155 TWh) with just 4.8 million billion women and girls live on less than $2 per day, and this residents.12,13 There is only enough electricity generated in the feminization of poverty is endemic to areas without electric sub-Sahara to power one light bulb per person for three hours power.9 Merely gathering traditional fuels consumes a large a day.14 Africa has 15% of the world’s population—50% of part of a woman’s day throughout the developing world. Girls these people live without electricity. In fact, of the 25 nations are kept out of school to obtain fuel. In areas such as South at the bottom of the UN HDI (see Figure 1), 24 are in Africa.15 Darfur, women walk up to seven hours per day to collect fuel, making mothers and their daughters highly susceptible to rob- In Cambodia, 69% of the population lacks access to electricity. bery, violence, and rape. This inequitable access to energy has In Pakistan, it is 33% and in Uganda an astounding 92%. Of the far-reaching socioeconomic ramifications. For example, the almost 160 million people in Bangladesh, 63 million lack access 16 infant mortality rate in Germany is less than four per 1000 to any sort of electric power. About three billion people use live births; in Nigeria, it is 74. In the European Union, virtually rudimentary stoves to burn wood, coal, charcoal, and animal 100% of the population has improved sanitation; in Indonesia dung, releasing dense black soot into their homes and the alone, 104 million people lack such sanitation.10 environment. Annual deaths from this household air pollution exceed four million per year.17,18 This gathering and burning of No nation holds more of the world’s poor than India. At least wood and other biomass leads to deforestation, erosion, land 300 million people have no power whatsoever and more than degradation, and contaminated water supplies. Families are 700 million people lack access to modern energy services for pushed off the land and migrate to cities in search of a better life. lighting, cooking, water pumping, and other productive pur- poses. One hundred million do not have an improved water URBANIZATION REVEALS THE IMPORTANCE supply and over 800 million lack access to improved sanita- OF ON-GRID ELECTRICITY tion. These problems will only intensify going forward as India has about 630 million people less than 25 years old and will Much energy poverty occurs in rural locations; in such - set surpass China as the most populated nation before 2030.11 tings, off-grid options, such as roof-top solar, have much to

An increasingly urban global population presents challenges, but also an opportunity to increase electrification rates.

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contribute. Undoubtedly, such solutions must play a role. In natural gas, liquid fuels, and chemicals, although CCS, which the near term, more efficient stoves and cleaner cooking fuels will be much less expensive at such facilities, will be required could dramatically improve indoor air quality and save lives. to control CO2 emissions. The liquid fuels produced from coal However, rural off-grid solutions may only meet the minimum conversion inherently have less sulfur than petroleum-derived standards for electricity. It would be difficult, if not impossible, fuels, which can address another major contributor to air for rural, minimal electrification to support the job-creating pollution by offering cleaner transportation fuels. Finally, the growth and industries so sorely needed to fundamentally potential for less direct coal use is significant: Only about 53% address energy poverty. Perhaps most importantly, to expect of China’s coal demand is for power generation, compared to to rely only on off-grid solutions because of where energy over 90% in the U.S.4 Together, these steps could significantly poverty occurs today ignores a pressing reality: rapid global reduce China’s air quality problems and allow continued eco- urbanization. nomic growth.

Urban migration is occurring on an unprecedented scale—over WHAT IS NEEDED TO MEET ELECTRICITY seven billion people will live in cities by 2050. The cities of the DEMAND AT SCALE? future will be massive. In 1990, the world had 10 cities of over 10 million people. By 2050, there could be as many as 100 The International Energy Agency (IEA) has defined basic elec- such “megacities”.19 The number of people urbanizing in India tricity access as an average of 250 kWh per rural household alone will exceed 11 million per year—equivalent to the cur- per year and 500 kWh per urban household per year.24 Such rent population of Delhi proper. Cities cannot be built without limited access is far removed from levels of modern consump- electricity, steel, cement, and associated materials. The level tion. Basic energy access as defined for rural areas would be of production required for these materials depends on ade- enough for a household to power a fan, a mobile phone, and quate resources, including electricity, being available. There is two fluorescent light bulbs for five hours a day (see Figure 2). a model for such growth and urbanization that already exists. China has demonstrated that low-cost electricity, fueled 70% Although even this basic level of electrification would increase by coal, can be a solution to debilitating energy poverty. Over the standard of living for some people, it is not enough to the last 20 years, China has expanded access to electricity and enable the growth and job creation needed to combat poverty. lifted over 650 million people out of poverty.20 In fact, at the Perhaps this is best explained by the Worldwatch Institute: global level, over 90% of people lifted from poverty since 1990 “Modern energy sources provide people with lighting, heat- were Chinese; power generation from coal in China increased ing, refrigeration, cooking, water pumping and other services 700% and GDP per capita rose eightfold.21 that are essential for reducing poverty.”25 I believe that providing only basic energy to developing nations will constitute During the same period, life expectancy increased by five “global poverty maintenance” programs in the name of uni- years, infant mortality declined 60%, and 600 million people versal energy access. gained new access to improved water sources.22 As women are disproportionately affected by energy poverty, they are also major beneficiaries when it is alleviated. The maternal TOMORROW’S ENERGY SOURCES mortality ratio in China has dropped from 110 per 1000 live births to 32 in 2013.23 Today universal access to electricity has All viable electricity sources will play roles in coming decades been achieved in China, allowing families to light their homes, if real strides are going to be made to alleviate energy poverty. refrigerate food and medicine, and reduce indoor air pollution In fact, the world will need more electricity from all sources. through more efficient means of cooking. Forecasters such as the IEA are already projecting major increases in on-grid electricity generation from gas (89%), The industrialization and electrification of China has come at nuclear (51%), and non-hydro renewables (358%) from 2011 to a price. The largest cities are experiencing major air pollution 2035 under the Current Policies Scenario.4 These resources will problems and both direct coal combustion for heating and be pushed, as will be coal. Today coal provides about 6000 TWh coal-fired power plants contribute to this problem. Although of electricity in the developing world. In 2035, the IEA’s Current China is expected to continue to rely on coal for electrifica- Policies Scenario projects coal will provide 12,300 TWh. Even tion, the country plans to dramatically reduce the emissions in the IEA’s much more conservative New Policies Scenario from coal-fired power plants by replacing older plants with (assuming all new policies announced are fully enacted), coal advanced coal-fired units, adding environmental controls, and accounts for over 9500 TWh in 2035. Replacing coal in this increasing efficiency via cogeneration of heat and power. In growth context would be impossible—and such efforts would addition, state-of-the-art coal conversion facilities are mov- yield an increase in energy poverty. In many countries, coming forward. These ultra-clean facilities will produce synthetic paring the percentage of generation capacity to percentage of

14 actual generation also helps to highlight coal’s real role: Coal’s technology, operate at increasingly higher temperatures and share of generation (as a percentage) is almost always signifi- pressures and, therefore, achieve higher efficiencies than cantly greater than its capacity percentage. For decades, coal conventional plants. Upwards of 500 GW of supercritical units has been the default fuel when sanguine projections of gas, are in operation or planned around the world, but many more nuclear, and wind have fallen short. This is one of the reasons are needed.26 Highly efficient modern coal plants emit up to 27 the IEA has projected that coal will supply at least 50% of the 40% less CO2 than the average coal plant currently installed. on-grid electricity to eliminate energy poverty by 2030.24 Importantly, these supercritical plants are a prerequisite for next-generation development of CCUS, which itself is broadly Clearly, attempting to remove the contribution of one energy recognized as required for global emission goals, which was source is not a viable strategy—especially when attempting the other important component of the Copenhagen Accord. to eradicate energy poverty. Nevertheless, western financial institutions such as the U.S. Export-Import Bank, the World Bank, and the European Bank for Reconstruction and A PLAN TO END ENERGY POVERTY Development have refused to fund coal projects even in areas of abject electricity poverty. Such a stance disregards the need The underlying theme of the position presented here is for widespread electrification above and beyond basic access. straightforward: Electricity, socioeconomic security, and a It can also be argued that such a position is counterproductive clean environment are inalienable human rights. Efforts to to the fundamental objective of such institutions, which is to eliminate coal-fired power plants would forgo an opportunity promote development and alleviate poverty. to help meet burgeoning electricity demand, reduce deprivation, elevate the global quality of life, and significantly reduce ENVIRONMENTAL IMPACT emissions from energy. Without contributions from coal, economic growth will be stunted, the environment will be Development banks and other poverty alleviation groups do degraded, and the crisis of energy poverty will not be solved. If not need to choose between alleviating poverty and environ- a global goal is truly the “[e]radication of poverty in the field,” mental protection. As has been explained, there are substantial the world’s most abundant source of electricity must remain 28 environmental benefits to electrification. In addition, clean an integral part of the solution. Policymakers must recognize electricity generation from coal could be assured by sup- the scale of electricity required to meet that goal. By 2050, porting plants with high efficiency, advanced environmental the world will have 9.6 billion people, with the large majority controls, and that are made ready to implement CCS/CCUS. in cities, where they have fuller access to electricity. I agree with many coal industry leaders that we should implement Clean coal technologies are in use today and allow for the con- a technologically based plan, which will help meet the ever- sumption of more coal with greatly reduced emissions. New rising need for power and improve the lot of all members of pulverized coal combustion systems, utilizing supercritical the human race.

14,000 5 hours a day of...1 fan...1 mobile phone...2 ﬂourescent bulbs 12,000 1112 1 10 2 10,000 9 3 8 4 8000 7 6 5

6000

[kWh/(capita·yr)] 4000 Average ElectricityAccess Average 2000

0 U.S. EU China World India Pakistan Sub-Saharan IEA Avg.* Africa FIGURE 2. Electricity access of select nations and a comparison to IEA’s basic energy service in rural settings24 *250 kWh per rural household, 500 kWh per urban household

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The five most important steps of a plan to increase access to 10. Central Intelligence Agency. (2013). The world factbook, Nigeria, clean electricity include: Germany, Indonesia, www.cia.gov/library/publications/the- world-factbook/ 11. Rajendram, D. (2013, 10 March). The promise and peril of India’s 1. Work to eliminate energy poverty by ensuring that at least youth bulge. The Diplomat, thediplomat.com/2013/03/the- half of on-grid new generation is fueled by coal promise-and-peril-of-indias-youth-bulge/ 2. Replace older, traditional coal plants with plants utilizing 12. U.S. Energy Information Administration. (2014, February). advanced coal technologies Electric power monthly, www.eia.gov/electricity/monthly/ 3. Develop at least 100 major CCS/CCUS projects around the current_year/february2014.pdf 13. IRENA. (2012). Africa’s renewable future, www.irena.org/ world within 10 years DocumentDownloads/Publications/Africa_renewable_future. 4. Deploy significant coal‐to‐gas, coal‐to-chemicals, and coal‐ pdf to‐liquids projects globally in the next decade, which will 14. World Bank. (2013). Fact sheet: Infrastructure in sub-Saharan spur industry and reduce pollution from transportation Africa, web.worldbank.org/WBSITE/EXTERNAL/COUNTRIES/AF fuels. Note that such projects would be particularly useful RICAEXT/0,,contentMDK:21951811~pagePK:146736~piPK:1468 30~theSitePK:258644,00.html for low-cost CCS/CCUS demonstrations. 15. SABC. (2013, 25 May). Free Africa from poverty and conflict: AU, 5. Commercialize next‐generation clean coal technologies www.sabc.co.za/news/a/8bce1b804fc0bb519d4eff0b5d39e4 to achieve near‐zero emissions, with supercritical power bb/Free-Africa-from-poverty-and-conflict:-AU-20132505 plants as the next step along that path 16. World Bank. (2013). Access to electricity (% of population), data, worldbank.org/indicator/EG.ELC.ACCS.ZS

st 17. Yamada, G. (2013). Fires, fuel and the fate of 3 billion. New York: This plan employs 21 century coal technology to cleanly and Oxford University Press. affordably use abundant global reserves—which approach 18. World Health Organization. (2014). Household (indoor) air 900 billion tonnes, are distributed across 70 countries, and are pollution, www.who.int/indoorair/en/ accessible through a far reaching and expanded network of 19. World Energy Council. (2011, December). Global Transport established infrastructure—to produce and deliver electricity Scenarios 2050, www.worldenergy.org/publications/2011/global -transport-scenarios-2050/ to all, especially to the billions of children, women, and men 20. Mackenzie, A. (2013, 8 August). Productivity boost will keep us who currently live in energy poverty.29 at No. 1. The Australian, www.theaustralian.com.au/business/ opinion/productivity-boost-will-keep-us-at-no-1/story- REFERENCES e6frg9if-1226693062147 21. UN. (2013). We can end poverty, www.un.org/millenniumgoals/ 1. United Nations (UN). (1972, 16 June). Report of the United poverty.shtml Nations Conference on the Human Environment, www.unep. 22. World Bank. (2013). World development indicators, data, org/Documents.Multilingual/Default.asp?documentid=97&arti worldbank.org/indicator, (accessed 2013). cleid=1503 23. World Bank. (2014). World development indicators, data, 2. National Academy of Engineering. (2003). The greatest worldbank.org/indicator, (accessed October 2014). engineering achievements of the 20th century, www. 24. IEA. (2011, November). World energy outlook 2011, www.iea. nationalacademies.org/greatachievements/List.PDF org/publications/freepublications/publication/world-energy- 3. International Energy Agency (IEA). (2002, September). World outlook-2011.html energy outlook 2002, www.worldenergyoutlook.org/media/weo 25. Worldwatch Institute. (2012, 31 January). Energy poverty website/2008-1994/weo2002_part1.pdf, www.worldenergy remains a global challenge for the future, www.worldwatch.org/ outlook.org/media/weowebsite/2008-1994/weo2002_part2. energy-poverty-remains-global-challenge-future-1 pdf 26. Platts. (2014). New Power Plant Database, 2014. 4. IEA. (2013, October). World energy outlook 2013. 27. World Energy Council. (2013). World energy resources: Coal, 5. UN News Centre. (2013, 13 June). World population projected www.worldenergy.org/wp-content/uploads/2013/10/WER to reach 9.6 billion by 2050, www.un.org/apps/news/story. _2013_1_Coal.pdf asp?NewsID=45165#.VDXo9haNWFI 28. European Bank for Reconstruction and Development, Eradicating 6. World Bank. (2013). World development indicators: Human poverty in the field, www.ebrd.com/pages/news/features/taff. Development Index, 2013, data.worldbank.org/indicator shtml 7. UN Framework Convention on Climate Change. (2009). Full 29. BP. (2014, August). Statistical review of world energy, www. Text of the Convention, unfccc.int/essential_background/ bp.com/content/dam/bp/pdf/Energy-economics/statistical- convention/background/items/1362.php review-2014/BP-statistical-review-of-world-energy-2014-full- 8. UN. (2014). We can end poverty, www.un.org/millenniumgoals/ report.pdf childhealth.shtml (accessed October 2014). 9. SowHope. (2013). About us, www.sowhope.org/aboutus The author can be reached at [email protected]

16 ENERGY POLICY

Understanding the National Enhanced Oil Recovery Initiative

By Patrick Falwell Going forward, NEORI will work to educate policymakers Solutions Fellow, Center for Climate and Energy Solutions across the political spectrum and the broader public about

the opportunity for CO2-EOR to serve as a national solution to Brad Crabtree energy and environmental challenges. Vice President, Fossil Energy, Great Plains Institute

“Improved federal incentive ince 2011, the Center for Climate and Energy Solutions (C2ES) and the Great Plains Institute (GPI) have convened could lead to the production of Sthe National Enhanced Oil Recovery Initiative (NEORI). Bringing together leaders from industry, the environmental over eight billion barrels of oil community, labor, and state governments, NEORI has worked to advance carbon dioxide enhanced oil recovery (CO2-EOR) and the underground storage of as a key component of U.S. energy security, economic, and environmental strategy. Currently, most CO2-EOR is done with more than four billion tonnes natural underground reservoirs of CO2, yet the industry’s future growth depends on taking advantage of the large amounts of of CO2 over 40 years…” CO2 that result from electricity generation and industrial processes. NEORI therefore is working to turn a waste product into a commodity and to encourage policies that will help bring BACKGROUND ON CO2-EOR an affordable supply of man-made CO2 to the market.

As such, NEORI has offered consensus recommendations for Although commonly considered a “niche” extractive tech- federal- and state-level policy action. In May, Senator Jay nology, CO2-EOR is a decades-old practice. Since the 1970s, Rockefeller (D-WV) introduced legislation in the U.S. Congress CO2-EOR projects have utilized CO2 to produce additional oil adopting NEORI’s centerpiece recommendation to reform from otherwise tapped-out fields. CO2 readily mixes with oil and expand an existing federal tax incentive for the capture not recovered by earlier production techniques, swelling the of man-made CO2 and its geologic storage through CO2-EOR. stranded oil and bringing it to the surface. The CO2 is then separated from the oil and re-injected in a closed-loop process.

Each time CO2 is cycled through an oil reservoir, the majority of it remains trapped in the underground formation, where,

over time, all utilized CO2 will be stored permanently.

Today, CO2-EOR in the U.S. accounts for over 300,000 barrels of oil production per day, or nearly 5% of total annual domestic 1 production. More than 4000 miles of CO2 pipelines are in place

and, as of 2014, approximately 68 million tonnes of CO2 are

being injected underground annually for CO2-EOR. Nearly 75%

of this CO2 is from naturally occurring deposits, but over time

the supply of CO2 from man-made sources is expected to grow

significantly. Currently, 11 U.S. states have CO2-EOR projects. Most are in the Permian Basin of Texas, with new activity emerging on the Gulf Coast and in the Mountain West. Untapped In May 2014 Senator Jay Rockefeller introduced legislation opportunities exist in California, Alaska, and a number of states incorporating the main principal of the National Enhanced Oil in the industrial Midwest. Estimates suggest that CO2-EOR could Recovery Initiative. (creativecommons.org/licenses/by/2.0/) ultimately access 21.4–63.3 billion barrels of economically

www.cornerstonemag.net 17 ENERGY POLICY

2 recoverable reserves. Recovering this oil would require 8.9–16.2 2. Income taxes on private royalties collected from CO2-EOR billion tonnes of CO2 that would predominantly come from man- producers made sources. Technically recoverable reserves offer potential 3. Royalties from CO2-EOR production on federal land to produce additional oil and utilize more man-made CO2 that is currently otherwise emitted into the atmosphere. Together these sources equate to nearly 20% of the sales value of an additional barrel of oil and generate the source

The main barrier to taking advantage of CO2-EOR’s potential of public revenues that will in turn cover the cost of newly has been an insufficient supply of affordable CO2. For an oilfield allocated incentives. operator looking to implement CO2-EOR on a depleted oilfield, there is a cost gap between what they could afford to pay for NEORI’s most recent analysis of the budget implications of

CO2 under normal market conditions and the cost to capture a tax incentive reflects the legislation introduced by Senator and transport CO2 from power plants and industrial sources. Rockefeller. This analysis shows that an improved federal For some industrial sources, such as natural gas process- incentive could lead to the production of over eight billion ing or fertilizer and ethanol production, the cost gap is small barrels of oil and the underground storage of more than four

(potentially $10–20/tonne CO2). For other man-made sources billion tonnes of CO2 over 40 years and generate federal rev- of CO2, including power generation and a variety of industrial enues that exceed the value of tax incentives awarded within processes, capture costs are greater, and the cost gap becomes the U.S. Congress’ standard 10-year budget window. much larger (potentially $30–50/tonne CO2). Recognizing the cost gap as a significant barrier, NEORI has worked to deter- mine the role that public policy can play in narrowing it. “For the last three years, NEORI NEORI’S CONSENSUS RECOMMENDATIONS has brought together a broad and AND ANALYSIS diverse group of constituencies For the last three years, NEORI has brought together a broad and diverse group of constituencies that share a common inter- that share a common interest in est in promoting CO2-EOR. Some NEORI participants support CO -EOR as a way to provide a low-carbon future for coal by 2 promoting CO2-EOR.” managing and avoiding its carbon emissions. Others are interested in the jobs and economic growth that deploying new CO2 capture projects, pipelines, and EOR operations will bring. Still other participants want to advance innovative technologies that NEORI PROPOSES AN ENHANCED can capture and permanently store CO2 underground. Despite FEDERAL INCENTIVE differences of opinions among participants on other issues, all agree that CO2-EOR is a positive endeavor and that public policy NEORI recommends a reform and an expansion of an existing can play an important role in realizing CO2-EOR’s many benefits. federal tax incentive, the Section 45Q Tax Credit for Carbon As such, NEORI’s participants have crafted a set of consensus Sequestration. First authorized in 2009, the 45Q tax credit recommendations for federal and state policy incentives to provides a $10 tax credit for each tonne of CO2 captured from enable the widespread deployment of carbon capture tech- a man-made source and permanently stored underground nologies to provide CO2 for use in CO2-EOR, while addressing through enhanced oil recovery (a $20 tax credit is available for concerns about how incentives have been allocated in the past. CO2 stored in saline formations). While enacted with the best of intentions, the existing 45Q program has been unable to encour- To support its consensus recommendations, NEORI also pre- age widespread adoption of carbon capture technologies for two pared a quantitative analysis to estimate the extent to which a main reasons. First, 45Q is only authorized to provide tax credits federal initiative could spur new CO2-EOR projects and improve for 75 million tonnes of CO2, a relatively small amount consider- the federal budget at the same time. An incentive awarded for ing how much CO2 could possibly be utilized through CO2-EOR. capturing CO2 from man-made sources for use in CO2-EOR has As of June 2014, tax credits for approximately 27 million tonnes the potential to be self-financing, given that it could lead to of CO2 had already been claimed, and it is foreseeable that the new oil production that is taxed at the federal level. CO2-EOR remaining pool of credits will be exhausted in the near future. in the U.S. generates federal revenue from three sources: Second, 45Q has been unable to provide needed certainty to carbon capture project developers that they will be able to 1. Corporate income taxes collected on the additional oil claim the incentive, due to rigid definitions in the tax code and production the lack of a credit reservation process. Carbon capture project

18 developers have not been able to present the guarantee of or tranches, would be established. The creation of separate credit availability when seeking private-sector finance. lower-cost industrialA and higher-cost industrialB tranches for power plants would ensure that an incentive is available for

Under NEORI’s proposal, a larger pool of 45Q credits would be the diversity of potential man-made sources of CO2. established, while suggested reforms would increase certainty and private-sector investment, improve transparency, and Tax Credit Certification help the program pay for itself fiscally within 10 years. A certification process would provide essential up-front- cer Allocating New 45Q Credits via tainty to carbon capture project developers and enable them Competitive Bidding and Tranches to reserve their allocation of 45Q tax credits to be claimed in the future. Upon receiving an allocation of 45Q tax credits To minimize the cost of new 45Q tax credits to the federal gov- through competitive bidding, a project would have to apply ernment, NEORI recommends that carbon capture projects for and meet the criteria of certification within 90 days. For of similar cost bid against one another for allocations of tax example, a carbon capture project would need a contract credits. Under annual competitive bidding processes, carbon in place to sell its CO2 for use in CO2-EOR to be certified. To capture projects would bid for a certain tax credit amount that maintain certification, a carbon capture project would have to would cover the difference between their cost to capture and complete construction in three years, if it is a retrofit, and five transport CO2 and the revenue they would receive from selling years, if it is a new facility. CO2 for use in CO2-EOR. The project submitting the lowest bid would receive an allocation of tax credits, and allocations would be made to capture projects up to specified annual limits. Revenue Positive Determination and Program Review Given the wide difference in capture costs for potential Following the seventh annual round of competitive bidding, man-made sources of CO2, three separate pools of credits, the U.S. Secretary of the Treasury would assess whether newly allocated 45Q tax credits have been revenue-positive to the federal government. If the new 45Q tax credits are not proving to be revenue-positive, the Secretary will make recommendations to Congress to improve the program. Otherwise, competitive bidding will continue until the next review.

The Secretary of the Treasury also would be advised by a panel of independent experts.

Annual Tax Credit Adjustment Based on Changes in the Price of Oil

Each year, the value of claimed 45Q tax credits would be adjusted up or down to reflect changes in the price of oil. In

most instances, the price that CO2-EOR operators would pay CO2

providers for their CO2 is linked explicitly to the prevailing price

of oil. When the price of oil rises and CO2-EOR operators are

willing to pay more for CO2, the value of 45Q tax credits would be adjusted downward to ensure the federal government does not pay more than needed. Conversely, when oil prices fall, the value of 45Q tax credits would be adjusted upward, ensuring that carbon capture projects receive sufficient revenue.

Tax Credit Assignability

Potential carbon capture project developers include electric NEORI recommends the allocation of new 45Q tax credits. power cooperatives, municipalities, and startup companies.

www.cornerstonemag.net 19 ENERGY POLICY

NEORI is designed to boost U.S. domestic oil production while providing much-needed financial support for CCUS projects.

how CO2-EOR can generate net federal revenue from domestic “NEORI members believe that oil production, meet domestic energy needs, safely store man- made CO2 underground, and help advance and lower the costs of carbon capture technology. CO2-EOR offers broad benefits and the rare opportunity to unite NOTES policymakers and stakeholders in A. Lower-cost industrial sources of CO2 include natural gas processing, ethanol production, ammonia production, and existing projects involving the gasification of coal, petroleum residuals, common purpose.” biomass, or waste streams.

B. Higher-cost industrial sources of CO2 include cement production, Not all of these entities have sufficient tax liability to allow iron and steel production, hydrogen production, and new-build projects involving the gasification of coal, petroleum residuals, them to realize the economic benefit of a tax credit. As such, biomass, or waste streams. NEORI recommends that carbon capture projects have the ability to assign 45Q tax credits to other parties within the REFERENCES CO2-EOR supply chain. This provision could facilitate tax equity partnerships, but only among entities directly associated with 1. Kuuskraa, V., & Wallace, M. (2014, 7 April). CO2-EOR set for the project and managing the CO2. growth as new CO2 supplies emerge. Oil & Gas Journal, www. ogj.com/articles/print/volume-112/issue-4/special-report-eor- heavy-oil-survey/co-sub-2-sub-eor-set-for-growth-as-new-co- CONCLUSION sub-2-sub-supplies-emerge.html 2. Wallace, M., Kuuskraa, V., & DiPietro, P. (2013). An in-depth

look at “next generation” CO2-EOR technology. National Energy In a time of considerable disagreement on U.S. energy and cli- Technology Laboratory, www.netl.doe.gov/File%20Library/ mate policy at the federal level, NEORI members believe that Research/Energy%20Analysis/Publications/Disag-Next-Gen- CO2-EOR offers broad benefits and the rare opportunity to CO2-EOR_full_v6.pdf unite policymakers and stakeholders in common purpose. The NEORI coalition therefore remains committed to educating The authors can be reached at [email protected] and members of both political parties and the broader public as to [email protected]

20 Developing Country Needs Are Critical to a Global Climate Agreement

By Benjamin Sporton original “Earth Summit” in Rio de Janeiro, the negotiation pro- Acting Chief Executive, World Coal Association cess produced the Kyoto Protocol, which came into effect in

2005 but covered only around one third of global CO2 emissions. A 2009 summit in Copenhagen was originally intended to be the apex of the process with a binding global deal on s another round of climate talks approaches, recent emissions reduction, but it failed to live up to expectations. headlines have highlighted the critical role developing World leaders will gather again in Paris in November 2015 countries play in achieving a climate agreement—and A for the 21st Conference of the Parties (COP21) to the United they are. Concerned about the restrictions it might place on Nations Framework Convention on Climate Change (UNFCCC) their efforts to grow their economies and eradicate poverty, for what is now expected to be the pinnacle of the climate many developing countries are cautious about what a future negotiations process. global agreement on climate change might mean. With one billion people living in extreme poverty in addition to a similar number with incredibly low standards of living, it is hardly surprising that poverty eradication ranks number one on the list “There is a pathway that provides a of priorities for developing country governments.1 The recent proposal document for new Sustainable Development Goals role for coal in achieving both climate also acknowledged that “poverty eradication is the greatest global challenge facing the world today”.2 and development objectives.”

This is the reason that developing countries are key to a global climate agreement: Any proposed agreement that hampers This September, UN Secretary General Ban Ki-moon hosted a their ability to grow their economies and eradicate poverty summit in New York intended to push climate change back up will not win their support. the international agenda and spur action toward November 2015. With celebrity endorsements and a series of coordinated THE LONG AND WINDING ROAD announcements from activists, governments, and the private sector, the summit did have some success in raising the profile Negotiations toward a global agreement on climate change of an issue that has struggled to maintain the profile it once have been long and tortuous. Beginning in 1992 with the had, but which has since been drowned out by other priorities, chief among them economic and security crises.

Ultimately, however, the negotiation process has struggled for more than two decades because of a fundamental disconnect between developed and developing countries. This disconnect centers on a desire by developed countries to require emissions reductions commitments by developing countries while they are still developing—potentially limiting the ability of those countries to grow their economies and eradicate poverty. It comes about because many in the developed world refuse to acknowledge that the development pathway their countries took—one that relied on abundant, affordable, and reliable energy—is the pathway that the developing world will United Nations Secretary-General Ban Ki-moon, left, is need to take if it is truly to eradicate poverty. joined by President François Hollande of France at a news conference on climate change during the Climate Summit, All sources of energy have a role to play in achieving climate and New York, U.S., 23 September 2014. (AP Photo/Jason development objectives. An overemphasis on renewable tech- DeCrow) nologies, however, risks limiting developing countries to “light

www.cornerstonemag.net 21 ENERGY POLICY

Coal Coal’s role in development explains why coal consumption in Southeast Asia is projected to grow at 4.8% a year through Renewables to 2035 along with significant growth in other developing regions (see Figure 1).7 It is why a 2012 report from the World Gas Resources Institute8 identified 1199 planned new coal plants Nuclear (representing 1400 GW) across 59 countries—most of them in developing and emerging economies. Oil

-100 0 100 200 300 400 500 600 700 Coal’s critical role in development is one of the reasons coal TWh has been the fastest growing fossil fuel for decades and why its FIGURE 1. Southeast Asia incremental electricity generation share of global primary energy consumption in 2013 reached by fuel: 2011–20357 30.1%, the highest since 1970.9 Even under the IEA’s New Policies Scenario (which accounts for all currently announced climate pol- bulb and cook stove” solutions: that is, solutions that address icies) coal demand is expected to grow from 3800 million tonnes the immediate needs of poverty and climate without addressing of oil equivalent (Mtoe) today to almost 4500 Mtoe in 2035.5 the longer-term fundamentals needed for poverty alleviation. These figures alarm climate activists who argue for an end to coal This fact was recognized in recent remarks by World Bank and encourage divestment from the coal industry. What they President Jim Yong Kim at the U.S.–Africa Leaders Summit in ignore, however, is that there is a pathway that provides a role August when he said that “there’s never been a country that for coal in achieving both climate and development objectives. has developed with intermittent power”3 and that, despite recent policy announcements, the World Bank would still A PATHWAY THAT INTEGRATES likely fund coal projects. His statement came as African leaders CLIMATE AND DEVELOPMENT argued they were living in “energy apartheid” and demanded the right to use their natural resources, particularly coal, to Alongside last year’s climate summit in Warsaw, the World fuel their economic development.4 Coal Association joined with the Polish government to host the International Coal and Climate Summit. The summit was If the climate negotiation process is to have any success it widely criticized by environmental groups for trying to take must integrate development and climate objectives. the focus away from climate negotiations, an argument which ignored the significant contribution cleaner coal technologies

THE DEVELOPMENT AND ENERGY CHALLENGE can make to achieving ambitions to reduce CO2 emissions. A key part of the summit was the launch of the Warsaw With 1.3 billion people globally lacking access to modern Communiqué, a document that called for increased interna- electricity and about double that number lacking access to tional action on deployment of high-efficiency, low-emissions clean cooking facilities, it is hardly surprising that developing (HELE) coal-fired power generation. country governments are focused on affordable and reliable energy to help grow their economies.5 Energy is fundamen- 21st-century HELE coal technologies have huge potential. It is tal to development. Without reliable modern energy services well known by now that a one percentage point increase in hospitals and schools can’t function and business and industry efficiency at a coal plant results in a two to three percentage can’t grow to provide employment and economic growth. point decrease in CO2 emissions. Less widely known is that the average efficiency of the global coal fleet currently stands In its 2011 World Energy Outlook, the International Energy at 33%. Off-the-shelf technologies for supercritical and ultra- Agency (IEA) reviewed what would be needed to meet their supercritical coal have about 40% efficiency or higher, while own “minimal energy access for all” scenario—a scenario that more advanced technologies expected to become available in would barely meet basic energy needs, but is the basis for the the near future will approach 50% efficiency. The IEA estimates proposed Sustainable Development Goal on energy access for that increasing the average efficiency of the global coal fleet all. Even in this minimal energy access scenario, half of the on- up to 40% would save around two gigatonnes of CO2 annu- grid electricity needed comes from coal.6 A more ambitious ally—roughly equivalent to India’s total annual emissions.10 target would likely see a much larger role for coal—and it is a more ambitious scale of development and energy access that Taken in the context of other climate policies the potential developing and emerging economies are targeting. That is impact of improving the efficiency of the global coal fleet is sig- why statistics about coal’s growing role in the world continue nificant. The Economist recently published a graphic showing to confound those who forecast its demise. the impact various policies or events have had on global CO2

22 emissions, which has been reproduced in Figure 2.11 If a global adverse to coal may have unintended consequences. initiative were in place to increase the average efficiency of In the 450 Scenario, which limits the global average the global coal fleet to the level of off-the-shelf technology, its temperature increase to 2°C, world investment in coal- two gigatonnes of savings would place it fourth on this list of fired capacity totals $1.9 trillion (25% higher than in 20 activities. It would be more than three times more effective the New Policies Scenario), of which $800 billion is for in reducing CO2 emissions than the global deployment of all plants fitted with carbon capture and storage (CCS). non-hydro renewable energies combined. Coal-fired power plants become more expensive on average because, in most regions, more efficient tech- Nowhere is the potential of HELE technology better demon- nologies are deployed, as well as greater emphasis strated than at J-Power’s Isogo power plant outside of Tokyo. on CCS technologies. If development banks withhold J-Power is the largest producer of coal-fired electricity in Japan financing for coal-fired power plants, countries that and is leading the way in HELE deployment with its 600-MW build new capacity will be less inclined to select the ultra-supercritical plant. The plant achieves gross thermal effi- most efficient designs because they are more expen- ciency of 45% and has reduced emissions to the equivalent of sive, consequently raising CO2 emissions and reducing a high-performing natural gas plant. the scope for the installation of CCS. In addition, many of the countries that build coal-fired capacity in the However, plants like that come at a cost. Developing countries 450 Scenario need to provide electricity supply to need international support to deploy the most efficient plants. those who are still without it, a problem that may be In the face of decisions by the World Bank and European Bank resolved less quickly if investment in coal-fired power for Reconstruction and Development to limit funding for coal plants cannot be financed. projects, the IEA raised some serious concerns:12 This is a warning from the IEA: International action against coal While increased investor awareness of climate-related creates two distinct risks. First, from a climate perspective, issues is a positive development, policies deliberately failing to invest in new coal technologies risks higher future

Cumulative Policy/Action Period Annual emissions* emissions

Montreal protocol 135.0 bn 1989–2013 5.6 bn Hydropower worldwide 2.8 bn 2010 2.8 bn Nuclear power worldwide 2.2 bn 2010 2.2 bn Increase avg. global efficiency of coal-fired power to 40% 2.0 bn China one-child policy 1.3 bn 2005 1.3 bn Other renewables worldwide 600 m 2010 600 m U.S. vehicle emissions & fuel economy standards** 6.0 bn 2012–2025 460 m Brazil forest preservation 3.2 bn 2005–2013 400 m India land-use change 177 m 2007 177 m Clean Development Mechanism 1.5 bn 2004–2014 150 m U.S. building & appliances codes 3.0 bn 2008–2030 136 m China SOE efficiency targets 1.9 bn 2005–2020 126 m Collapse of USSR 709 m 1992–1998 118 m Global Environmental Facility 2.3 bn 1991–2014 100 m EU energy efficiency 230 m 2008–2012 58 m U.S. vehicle emissions & fuel economy standards*** 270 m 2014–2018 54 m EU renewables 117 m 2008–2012 29 m U.S. building codes (2013) 230 m 2014–2030 10 m U.S. appliances (2013) 158 m 2014–2030 10 m Clean technology fund 1.7 bn project lifetime N/A EU vehicle emission standards 140 m 2020 N/A 11 FIGURE 2. Emissions reductions impact (in terms of billions tonnes CO2 equivalent) *Annual emissions are cumulative emissions divided by the relevant period. The estimate for the current emissions avoided under the Montreal protocol is eight billion tonnes CO2 equivalent. The annual figure for the collapse of the USSR refers to the years 1992–1998. **Cars and light trucks ***Heavy trucks

www.cornerstonemag.net 23 ENERGY POLICY

emissions from coal; second, failing to invest in coal threatens It is clear that if the November 2015 climate summit in Paris the energy access and development priorities in some of the is going to achieve any level of success, then it must support world’s poorest countries. the development ambitions of the world’s poorest countries. It must integrate the priorities of countries like India, which need to address their poverty situation and provide affordable AFFORDABLE, LONG-TERM ACTION and reliable electricity, with global climate ambitions. It means that rather than ignoring coal, the international community As the IEA notes, deployment of HELE plants is also an impor- must recognize 21st century coal as part of the solution. tant first step in the longer term drive for near-zero emissions coal-fired plants incorporating carbon capture, utilization, and REFERENCES storage (CCUS). CCUS technology is critical to achieving global climate objectives. More importantly, CCUS plays a significant 1. World Bank Group. (2014). Ending poverty and sharing pros- role in reducing the economic costs of limiting CO2 emissions. perity: Global Monitoring Report 2014/2015, www.worldbank. org/en/publication/global-monitoring-report The recent New Climate Economy report by the Global 2. United Nations. (2014). Outcome document – Open Working Commission of Energy and Climate, led by former Mexican Group proposal for Sustainable Development Goals, sustainable development.un.org/focussdgs.html, (accessed 29 September 2014). President Felipe Calderón, argued that substantial emissions 3. Ginski, N. (2014, 5 August). World Bank may support African coal cuts would effectively pay for themselves when a range of power, Kim says. Bloomberg, www.bloomberg.com/news/2014- co-benefits are considered.13 That reflected recent work from 08-05/world-bank-may-support-african-coal-power-kim-says. the Intergovernmental Panel on Climate Change (IPCC) which html, (accessed 30 September 2014). stated that annual GDP growth would decline by as little as 4. Scientific American. (2014). Africa needs fossil fuels to end energy apartheid, www.scientificamerican.com/article/africa-needs-fossil- 0.006 percentage points with substantial emissions reduction. fuels-to-end-energy-apartheid/, (accessed 30 September 2014). 5. International Energy Agency (IEA). (2013). World energy outlook Many environmental activists argue that this demonstrates 2013, www.worldenergyoutlook.org/publications/weo-2013/ the viability of renewable energy technologies as the exclu- 6. IEA. (2011). World energy outlook 2011, www.worldenergy sive energy pathway toward a near-zero emissions economy. outlook.org/publications/weo-2011/ 7. IEA. (2013). World energy outlook special report 2013: However, analysis by the Council on Foreign Relations’ leading Southeast Asia energy outlook, www.iea.org/publications/free energy expert Michael Levi noted that CCUS is far more critical publications/publication/SoutheastAsiaEnergyOutlook_ to achieving the 2°C target.14 He highlighted that in the IPCC WEO2013SpecialReport.pdf research, failing to deploy CCUS causes the cost of climate 8. World Resources Institute. (2012, November). Global coal risk action to rise by about 140%, but that the most likely outcome assessment, www.wri.org/publication/global-coal-risk-assessment 9. BP. (2014). Statistical review of world energy 2014, www. is that the 2°C target could not be reached at all. bp.com/en/global/corporate/about-bp/energy-economics/ statistical-review-of-world-energy.html 10. IEA. (2012). Energy Technology Perspectives 2012 – How to A CLIMATE DEAL CAN ACHIEVE secure a clean energy future. BOTH OBJECTIVES 11. The Economist. (2014, 20 September). The deepest cuts, www. economist.com/news/briefing/21618680-our-guide-actions- have-done-most-slow-global-warming-deepest-cuts If global action to reduce CO2 emissions is to be affordable and have a realistic chance of meeting the 2°C target it must 12. IEA. (2014). World energy investment outlook, www.iea.org/ publications/freepublications/publication/WEIO2014.pdf account for the role of cleaner coal technologies in achieving 13. The New Climate Economy. (2014). New climate economy, that aim. That is even more critical when the need for afford- newclimateeconomy.report/, (accessed 20 September 2014). able and reliable energy for development is accounted for. 14. Levi, M. (2014). Is solar power making climate policy cheap?, blogs.cfr.org/levi/2014/09/19/is-solar-power-making-climate- India’s new Environment Minister made clear recently where policy-cheap/, (accessed 30 September 2014). 15. Davenport, C. (2014, 24 September). Emissions from India his country’s priorities lie: “India’s first task is eradication of will increase, official says. The New York Times, www.nytimes. poverty … Twenty percent of our population doesn’t have com/2014/09/25/world/asia/25climate.html?_r=0, (accessed access to electricity, and that’s our top priority.”15 30 September 2014).

24 STRATEGIC ANALYSIS

The Flexibility of German Coal-Fired Power Plants Amid Increased Renewables

By Hans-Wilhelm Schiffer concerning energy and electricity consumption, the share of Executive Chair, renewable energy, and the reduction of greenhouse gas emis- World Energy Resources of the World Energy Council sions. A central component of this concept was to extend the Consultant and Advisor to the Executive Board of RWE AG operation time of nuclear power plants, at that time seen as a bridge technology in the era of renewable energy.

erman energy policy is determined by different ambitious targets. That is especially true as far asthe “Today, fluctuations in the feed-in Gelectricity sector is concerned. The main characteristics of electricity-sector policy are a complete phasing out of of renewables-based electricity nuclear energy, the transition to a power supply based mainly on renewable energy, and the reduction of energy consump- are already having a considerable tion by continuously increasing efficiency. The main purpose

of these changes is to reach a nearly CO2-free power supply impact on the load to be covered by by 2050. The central challenges are keeping the power system stable and secure while maintaining consumer electricity conventional power stations.” prices at a competitive, affordable level.

CURRENT STATUS AND TRENDS Following the Fukushima nuclear disaster in March 2011, however, the German conservative-liberal government coali- The German government´s energy policies have undergone a tion made an abrupt U-turn by mandating the complete profound change over recent years. In September 2010, the phase-out of 8.4 GW of nuclear capacity immediately, with the remainder (12.1 GW) to be decommissioned between government launched a comprehensive “Energy Concept” 2015 and 2022. With the decision to shut down all nuclear featuring a large number of policy goals for future decades capacity by 2022, the government returned to a phase-out schedule conceived in 2001 by the socialist-green government in power at the time. In the coalition contract of the new conservative-socialist government, signed in November 2013, the phasing-out decision for nuclear energy was con- firmed. Furthermore, the coalition partners agreed on slightly modified targets concerning the reduction of greenhouse gas emissions, the consumption of electricity, and the increase of the share of renewables in the electricity supply for 2020 (35%), 2025 (40–45%), 2035 (55–60%), and 2050 (80%).

The decision to phase out all nuclear power plants is generally considered a final one due to public pressure that accompa- nied the nuclear debate over past decades.

The envisaged expansion of renewable energy is a technological and financial challenge. The principal objectives of the Energiewende (Germany’s transformational energy policy) are: Germany’s coal- and gas-fired power plants are responsible for meeting fluctuations from the increased deployment of • Transitioning German power supply from a conventional- renewables. based system to one mainly based on renewable energy;

www.cornerstonemag.net 25 STRATEGIC ANALYSIS

• Keeping power prices on a competitive level for industry TABLE 1. Renewable energy capacity in Germany as of the and an affordable level for private households; end of 2013 • Ensuring continuous, secure supply. Source Capacity (MW) The main instrument being used to make renewable energy Wind Onshore 33,757 the backbone of the German power supply is the Renewable Wind Offshore 903 Energy Sources Act, last amended on 1 August 2014. This law provides guaranteed feed-in tariffs for renewable electricity Hydropower 5619 for 20 years after a power plant is commissioned. Grid opera- Biomass 8153 tors are obliged to purchase the entire quantity of renewable Solar Photovoltaic 35,948 electricity with priority. The trade companies pass on the deficit (i.e., feed-in tariff minus market price) to customers by Geothermal 24 imposing a reallocation charge. Source: AGEE-Stat, August 2014

The renewable capacity for power generation increased from The subsidies are financed via a reallocation charge that is paid 12,330 MW in 2000 (less than 10% of total capacity) to 40,357 by electricity consumers through a markup on the grid-access MW by the end of 2008 and to 84,404 MW by the end of fee. Starting on 1 January 2014, this reallocation charge was 2013 (45%) (see Figure 1). In 2000, renewable energy’s share increased to €62.40/MWh. The reallocation charge has now of consumption was less than 7%, then grew to over 25% by reached a level at which it is twice as much as the wholesale 2013. The total amount of renewable energy capacity on 31 price of electricity. December 2013 is shown in Table 1. A comparison between electricity prices reveals the dilemma Within just the last five years (between the end of 2008 and facing Germany today. Power prices for industry are on the the end of 2013) the capacity increase was 29,828 MW for same level as those in Japan. In fact, private customers in photovoltaics (PV) and 10,845 MW for wind energy. This dem- Germany pay even more for electricity than private consum- onstrates that the funding system for renewables has been ers in Japan. Within the EU, Germany’s private consumers pay quite effective. a higher price than any country except Denmark. Electricity prices in Germany are more than twice the OECD average and However, the growth of renewables in Germany has come three times as high as in the U.S. at a cost. The total feed-in amounts based on subsidized renewables in Germany stood at 125.7 TWh in 2013. The CHALLENGES FOR POWER PRODUCERS1 remuneration paid to plant operators and premium payments totaled €20.4 billion in 2013. Deducting income from mar- With the increase in renewable energy, power producers also keting, on balance, net subsidy payments were approximately face a new challenge. In the past a main focus was offsetting €16.2 billion in 2013. fluctuations in consumption between day and night,- work days and weekends, and seasonal variations. Today, feed-in intermittency has added a new source of fluctuations that Wind 9 19 5 are at least the same magnitude as those from changes in Photovoltaics 11 consumption. 19 5 Hydropower, biomass 11 These demand and renewable energy feed-in fluctuations 7 Fuel oil and other Natural gas must be continuously balanced to provide electricity grid sta- 7 19 bility, which is putting pressure on the conventional power 15 Hard coal generation portfolio. Power generation from conventional plants has to be able to flexibly adjust to the residual load 14 25 Lignite at any time (i.e., to compensate for the difference between 12 consumption and fluctuating renewable energy). This is a chal- 15 7 Nuclear lenge for grid operators, especially when high wind feed-ins in Power plant capacity Electricity production northern Germany force the “redispatching” of thermal units 186.8 GW (net) 596.4 TWh (net) intraday, often leading to lower coal-based output in the north FIGURE 1. Percentages of capacity and production of various and a ramp up of capacity in the south to keep the system in electricity sources (December 2013)1 balance.

26 The need for load adjustments by flexible power plants is par- However, since these markets are also expanding wind capaci- ticularly critical when an increase in electricity demand occurs ties and consumer behavior in all markets shows substantial at the same time as the feed-in from wind power plants dra- similarity, the capacity to adjust imports and exports to meet matically decreases. German electricity market fluctuations is limited.

There has been a need for load adjustments of >50 GW (i.e., Therefore, the required flexibility to meet load fluctuations >60% of the peak load) within an eight- to 10-hour period. This must be predominantly managed by existing national power sort of demand fluctuation is generally random, but can be plants. Existing power plants in Germany are all designed forecast up to two days in advance (e.g., via a wind forecast). to cater for flexible operation, and these requirements are equally met by new NGCC plants and new coal-fired power Thus, conventional power generation plants are faced with plants. massive technical and economic challenges. Today, fluctuations in the feed-in of renewables-based electricity are already Many of the conventional power plants operating in Germany having a considerable impact on the load to be covered by today were built in the 1980s and 1990s, before expansion conventional power stations. To illustrate the effect of such targets for wind and photovoltaic plants had been adopted. In fluctuations, looking closely at electricity demand and sources many plants, measures to allow greater flexibility have been can be helpful. Due to the high demand and low feed-in of implemented subsequently, so that power plants can meet electricity from renewable energies, on 24 January 2013 up increased requirements for market load adjustments. As a to 74,335 MW—92% of the peak demand of 80,739 MW in result, there are very few dedicated German baseload power Germany—had to be covered by conventional power plants. plants that do not allow for flexible operation. Conversely, on 24 March 2013, a Sunday with low electricity demand coupled with high feed-in from wind and solar, a The necessary operational flexibility of coal- and gas-fired minimum of 14,405 MW had to be covered by conventional power plants can be illustrated with an example from 1 and power stations. This represents a tremendous shift in the role 2 January 2012 (see Figure 2). On Sunday, 1 January, power of conventional power plants. demand was relatively low due to low industrial demand and mild temperatures of approximately 8°C (46°F). Around the Flexibility to Meet Load Fluctuations evening peak, a temporary daily maximum consumption of 56 GW was reached in the German power grid, after which The German electricity transmission network is part of the demand decreased to a minimum value of less than 41 GW European synchronous zone and is connected with neighbor- until the late evening. ing European markets. A regular exchange of electricity takes place with all adjacent countries (i.e., France, Netherlands, At the same time, the amount of wind feed-in temporarily Denmark, Poland, Czech Republic, Austria, and Switzerland). reached a very high level of more than 16 GW. Further feed-ins

GW GW 80 80

70 70 Gas 60 60 Increasing 50 power demand 50 Wind 40 40

30 30 Coal Declining 20 wind feed -in 20

10 10 Nuclear

0 0 Must-run Sunday, 1.1.2012 Monday, 2.1.2012 Sunday, 1.1.2012 Monday, 2.1.2012 FIGURE 2. Power consumption (left) and dispatch (right) of German power plants1

www.cornerstonemag.net 27 STRATEGIC ANALYSIS

that day came from other renewable energy sources, including 20 100% run-of-the-river hydro and biomass power plants, which also 18 90% benefit from feed-in priority. The feed-in from those plants consistently amounted to about 5 GW. The power generation 16 80% from photovoltaic plants was negligible due to the season as 14 70% well as the cloudy weather that weekend. on (GWh) 12 60%

On Sunday evening, after the renewable energy feed-ins were 10 50% accounted for, only a residual load of 21 GW had to be temporarily covered by other power plants available according to 8 40% Load factor (%) schedule. 6 30%

At 4:00 am on Monday, 2 January, power consumption soared Renewable ti genera 4 20% and reached a demand level of approximately 73 GW at around 2 10% noon. This corresponds to an increase of 32 GW within eight hours. At the same time the feed-in from wind power plants 0 0% decreased in the early hours of the morning due to declining 1 2 3 4 5 6 7 8 9 101112131415161718192021222324 Hour wind speeds and intermittently amounted to only 4 GW at Photovoltaics Wind CCPP new build* around noon. In parallel, a decrease in feed-in of about 12 GW Hard coal new-build Existing hard coal, optimized was registered on the supply side. Thus, overall, an additional FIGURE 3. Feed-in from renewables on 16 March 20121 power output of nearly 45 GW had to be provided by the ther- *Regular operation of two gas turbines and one steam turbine mal power plant portfolio within those eight hours. Source: www.transparency.eex.com

The left-hand side of Figure 2 displays the parallel development had previously been off the grid. Grid synchronization of fossil- of increased power consumption and decreased, intermittent fired plants commences approximately one to four hours after wind feed-in, requiring a high degree of load adjustment from initial boiler firing. Subsequent to the grid synchronization, the conventional power generation portfolio. newly started coal-fired power plants met the required load increase until about midday. Power generation from German nuclear power plants contributed, almost without interruption, a supply of about 12 GW. Generally, available gas-fired power plants are returned from There is a degree of flexibility available from the German nuclear downtime to meet the load peaks on Monday. The first feed- power stations, although their low-variable power generation ins from gas-fired plants are normally in the early morning, costs ensure that this is only used once the load adaptability from 5:00 am onward. Over the course of the day, load bal- of the fossil-fired power plants has been exhausted. As seen in ancing is mainly regulated by gas-fired power plants, and the the right-hand side of Figure 2, the necessary load adjustment coal-fired power plants remain at full load until the evening. of about 50 GW on Monday morning was almost completely provided by the coal- and gas-fired power plants. On the particular Monday being evaluated, load adjustments were made by a combination of available coal- and gas-fired On Sunday night, almost 40% of the coal-fired power plants power plants. In doing so, the coal-fired power plants pro- were still in operation, although the requirements for coal- vided about 75% of the required flexible output. fired power plants at that time had reduced to about 20–60% of their installed output capacity. Overall, their contribution was only about 10 GW. Flexible Use of Coal- and Gas-Fired Power Plants due to Fluctuations of PV Feed-In The conventional gas-fired power plants were almost completely off the grid on Sunday night, since part-load operation The average cycle between strong and weak wind phases of gas-fired power plants is considerably more expensive than is about three to five days in northwest Europe. Even in the it is for coal-fired power plants. event of short-term changes, as portrayed in the first example, the thermal power plant portfolio has several hours in which In the early hours of Monday morning the increase of residual to adjust load. load was initially covered by coal-fired power plants supporting the grid by means of less than full load operation. In parallel, Short-term feed-in fluctuations are also triggered by the out- additional coal-fired power plants went into operation that put of widely developed solar photovoltaic power plants in

28 LINGEN CCPP BoA1–3 BoAPLUS Max capacity: 2x440 MW Max capacity: 1000 MW Max capacity: 2x550 MW Min capacity: 520/260 MW Min capacity: 500 MW Min capacity: 350/175 MW Max load change rate: +/-32 MW/min Max load change rate: +/-30 MW/min Max load change rate: +/-30 MW/min 1100 MW

1000

800

600 2-boiler operation

400 2-boiler operation 1-boiler operation 200 1-boiler operation

5 10 15 20 25min 5 10 15 20 25min 5 10 15 20 25min FIGURE 4. Comparison of load flexibility of new-build gas- and lignite-fired power plants in the Rhineland1 Notes: BoA is a German abbreviation for “lignite-fired power station with optimized plant engineering“. BoA 1–3 are in operation andPLUS BoA is in the planning stages.

Germany. The effects can be seen from the beginning of spring 16 March was one of the first days in 2012 with intensive solar as the daily level of solar radiation increases. radiation in Germany. The feed-in from photovoltaic plants increased by about 16 GW between 8:00 am and 1:00 pm. The timing of the increase in solar radiation in the morning Between 2:00 and 6:00 pm, it decreased. On that day, wind does not coincide with the increase in power consumption. levels were extremely low (see Figure 3). While electricity demand increases between 4:00 and 8:00 am, the increase in photovoltaic feed-in occurs between 8:00 To cover peak consumption in the morning, coal- and gas-fired am and 1:00 pm. Similarly, photovoltaic feed-in decreases in power plants started operation. In order to accommodate the the evening, some hours before the decline in power con- temporarily high photovoltaic feed-in around midday, and sumption. Consequently, thermal power plants have to kick in afterward provide full load to cover the evening peak, the gas- at short notice twice—in the morning and in the evening—on fired and coal-fired power plants were intermittently operated days with a high photovoltaic generation. between partial and full-load operation.

TABLE 2. Sample flexibility parameters for coal- and gas-fired power plants

Natural Gas Hard Coal Lignite Hard Coal Existing Plant Parameter Unit CCPP New Builda New Build New Build (Optimized) Capacity MW 800 800 1100 300

Minimum-load point/rated-load % ~60 ~25–40 ~25b–40 ~20

point (Pmin/PRated)

Mean load change ratec %/min ~3.5 ~3d ~3 ~3 a Regular operation of two gas turbines and one steam turbine b Thanks to the “BoA-Plus” design (lignite-fired power plant with optimized plant technology plus upstream coal drying) a minimum-load point of 25% is possible today, but has not been implemented yet c With respect to rated load d In the lower load range (25–40%) the operating gradient differs from this value

www.cornerstonemag.net 29 STRATEGIC ANALYSIS

Figure 3 shows the course of intermittent feed-ins and the In contrast, a new coal-fired power plant has a lower minimum adjusted operation of conventional power plants (new gas and load capability of approximately 40%, with further potential steam power plant, new coal-fired power plant, and an existing to reduce this to 20–25%. The reason is that the output of the coal-fired power plant with optimized flexibility parameters), coal boiler is controlled via direct fuel combustion and not, as following changes in demand and available generation from is the case with a gas combined-cycle power plant, via a heat renewable energy sources. In the case of 16 March 2012, recovery steam generator with an upstream gas turbine. German coal- and gas-fired power plants were able to accommodate photovoltaic feed-in variations mutually because of German power plant operators have also made it possible their short-term flexible operating capability. to reduce the minimum load of operation at existing power plants by optimizing the boiler-turbine system using modern control systems. Today’s optimized coal-fired power plants are “Despite the continued increase able to operate at a partial-load level of less than 20% of full- load capacity. in renewable capacity, the role of The change (i.e., ramp) between partial load and full load at fossil fuels for power generation in power plants involves load changes of approximately three percentage points per minute, and the change in mode of Germany will be more or less the operation can therefore be achieved at all plants in less than half an hour (see Table 2 and Figure 4). same in 2023 as in 2013.” PROSPECTS1

Flexibility Characteristics of German Despite the continued increase in renewable capacity, the role Coal- and Gas-Fired Power Plants of fossil fuels for power generation in Germany will be more or less the same in 2023 as in 2013 (see Figure 5). In the regular configuration of two gas turbines and one steam turbine, the minimum load of a new gas-fired combined-cycle The fundamental reason is the complete phasing out of plant is typically around 60% of its installed capacity. An even nuclear power capacity by the end of 2022. By 2034 the lower minimum load is achievable by switching off one gas total capacity on the basis of renewables is expected to be turbine; this, however, causes a substantial decrease in effi- approximately 173 GW, which is twice as much as the peak ciency, and thus is rarely employed. load in Germany.2 However, a conventional capacity of 82 GW will still be needed (compared to 100 GW in 2012) to cover 634 TWh the demand when the wind is not blowing and/or the sun is 609 TWh 2 7.5% not shining. The required flexibility to meet the fluctuations 23.9% 527 TWh is being fulfilled just as well by coal-fueled as by gas-fueled Renewables 4.0% ~40% 27.1% power plants. These plants are being made increasingly flex- 15.4% Nuclear 29.2% ible, ensuring that they can continue to serve their important role in Germany’s electricity market.

Fossil REFERENCES 66.8% 65.4% 60.7% ~60% energy sources st (coal, gas etc.) 1. IEA Coal Industry Advisory Board. (2013). 21 century coal: Advanced technology and global energy solution. Paris: OECD/ IEA. www.iea.org/publications/insights/21stcenturycoal_final_ 1993 2003 2013 2023 web.pdf FIGURE 5. Gross power generation in Germany 1993–20231 2. 50Hertz Transmission/Amprion/ TenneT TSO/TransnetBW, Grid Source: AG Energiebilanzen (for 1993–2013); target of federal government development plan electricity 2014, Berlin/Dortmund/Bayreuth/ according to coalition agreement: 40–45% renewables in 2025 Stuttgart, 2014. (in German)

30 Toward Carbon-Negative Power Plants With Biomass Cofiring and CCS

By Janne Kärki achieved by employing CCS, utilizing high shares of biomass Research Team Leader, VTT Technical Research Centre of Finland fuels, or a combination thereof. By combining biomass cofiring and CCS, it is possible to achieve negative emissions (defined Antti Arasto as capturing CO2 from biomass combustion and storing it per- Business Development Manager, manently isolated from the atmosphere). This is one of the VTT Technical Research Centre of Finland few large-scale options to remove CO2 from the atmosphere, which highlights the importance of these technologies. However, such technologies require stronger government and international support to encourage deployment. In addition,

he goal of CO2 emissions reductions and renewable increased costs for CO2 emissions or CO2 emission perfor- energy incentives have led some power plant operators mance standards (EPS) could help advance the technology.1–3 Tto broaden their fuel palette to include various carbon- neutral biomass fuels. Biomass can be carbon neutral because it binds carbon from the atmosphere that is then released when it is burned, minimizing net emissions. “Combining biomass cofiring and

Carbon capture and storage (CCS), another potential option CCS … is one of the few large-scale to cut CO2 emissions from the power sector, is currently under extensive research, development, and demonstration glob- options to remove CO2 from the ally. CCS is advancing toward commercialization, but there are still hurdles, mostly nontechnical, that are impeding its wide- atmosphere...” spread deployment.

Greenhouse gas emission reduction targets are expected to FEASIBILITY OF COFIRING WITH be higher in the future and, therefore, the power sector and VARYING BIOMASS SHARES several other major industries may need solutions that can offer up to 80% reductions in emissions. In large-scale ther- Cofiring of coal and various types of biomass is now a mature mal power plants, this level of emissions reduction can be technology and is currently being successfully practiced globally. With technological advances, many limitations associated with it have been overcome. Many coal-fired plants have been converted or retrofitted to accommodate cofiring with limited impact on efficiency, operations, or lifespan.

However, there is much more to cofiring than simply adding a secondary fuel. Boiler technology and design remain critical issues when evaluating the maximum share of biomass that can be used without compromising boiler performance (output, efficiency, and power-to-heat ratio) or the lifetime of the boiler components.4

Various technologies have been developed to enable cofiring biomass with coal in pulverized coal (PC) boilers. The vast capacity of existing PC boilers offers great potential for increas- In locations where sustainable biomass is readily available, ing biomass utilization and economic benefits compared to cofiring with coal harnesses the advantages of each fuel. new stand-alone biomass power plants, which also are usually

www.cornerstonemag.net 31 STRATEGIC ANALYSIS

significantly smaller than PC plants. With cofiring, capital costs CONCEPTUAL STUDY OF BIOMASS are increased only marginally, while the high electrical effi- COFIRING VERSUS CCS ciency of large PC boilers and the favorable properties of coal ash can be exploited to reduce the operational risks. VTT Technical Research Centre of Finland has conducted several conceptual case studies on the feasibility of CCS and Utilizing biomass in an existing thermal power plant can be biomass cofiring. In the case study discussed below, the fea- accomplished through direct or indirect cofiring. Direct cofir- sibility of a coal-fired oxy-combustion CFB boiler with 99% ing is the most straightforward, most commonly applied, and CO2 capture and storage (Case I) is compared to cofiring large lowest-cost concept for partially replacing coal or other solid shares of biomass (Case II 70% and Case III 30%, with the bal- fossil fuels with biomass. In direct cofiring, biomass and coal ance from coal). These cases are compared to a base-case are burned together in the same furnace using the same or CFB coal-fired (air-fired, no biomass cofiring, and no CCS) separate fuel handling and feeding equipment, depending on 500-MWfuel greenfield power plant situated in Finland that the biomass, targeted biomass share, and site-specific charac- emits approximately 1.2 million tonnes CO2/year. teristics. The percentage of biomass that can be successfully employed in direct cofiring is modest, typically about 10%, The fuel mix affects the plant design, investment required, and and the type of biomass is limited mostly to pellet-type fuels. operational parameters. The plant fuel input (on an energy With torrefied biomass, however, higher shares are expected, basis) and designed steam parameters remain constant in up to tens of percentages. Indirect cofiring consists of convert- all cases. Therefore, the use of biomass or oxy-combustion ing the solid biomass to a gas or liquid prior to combustion in increases the required plant investment and operating costs. the same furnace with the other fuel. This allows for greater Additional investment for biomass cofiring is required for bio- amounts of biomass to be used, up to 50%. However, this mass handling and feeding equipment, additional loop seal approach requires greater investment and a larger footprint.5 heat exchangers, advanced coarse material removal, more expensive materials for heat transfer surfaces, larger flue gas In general, fluidized bed boilers offer the best fuel flexibility. ducts and fans, extra soot-blowers, and possibly injection of In a properly designed boiler, biomass fuels can be used combustion additives. Additional O&M costs include addi- with coal in any percentage from 0–100% in circulating fluid- tional chemical and maintenance costs. For the CFB-Oxy-CCS ized bed (CFB) boilers. The variety of biomass fuel options is case, the main additional investment involves boiler block increasingly diverse, although the availability of some biomass modifications, a cryogenic air separation unit (ASU), anda fuels can be limited. Power plants with high fuel flexibility can CO2 purification unit (CPU). The greatest impact of CCS on the adapt to the prevailing fuel market by optimizing the fuel mix.6 O&M costs is the efficiency penalty, which in this study was

assumed to be eight percentage points. The captured CO2 was One possibility to utilize biomass in existing PC boilers is to assumed to be transported and stored abroad with an overall 7,8 convert them into bubbling fluidized bed boilers. These retro- cost of €12/tonne CO2. The main assumptions and results, fits are routine for the major fluidized bed boiler technology including net electricity output, are provided in Table 1.7,8 suppliers, and numerous such conversions have been conducted in Europe. For example, at least eight conversions to The principal goal of the modeling was to evaluate annual enable pure biomass combustion have been carried out in cash flows from an investor’s point of view in the three

Poland since 2008, with capacities from 100–200 MWth. reduced-CO2 emission cases compared with the base case.

TABLE 1. Key assumptions and results from economic modeling

Case I Case II Case III Factor Base Case (CFB-Oxy-CCS) (70% bio) (30% bio)

Combustion mode Air Oxygen Air Air CCS No Yes No No Biomass share (%) 0 0 70 30 CO emissions reduction compared to base case 2 0 -0.91 -0.91 -0.39 (million tonnes/yr)

Electricity output (MWe) 213 173 208 210

32 Base Case Case I Case II Case III mostly dependent on electricity prices, CO2 and fuel costs, and 0 1.3 estimated peak load hours, which are all uncertain. For Finnish -10 -12 -14 -11 -0.3 -12.4 -5.0 thermal power plants with CCS, break-even prices of €70–100/ -20 tonne were presented by Teir et al.10 In comparison to these -23 -13 -31 -44 reported values, the CFB-Oxy-CCS case was quite competitive, -40 -15 but this is highly dependent on CO2 transport and storage costs, which were much lower in our estimation.10 In addition, -60 -64 at some locations sufficient biomass may not be logistically -38 -49 -38 or economically available. Similarly, CO2 storage sites are not -80 universally accessible. Therefore, the exact modeling results should not be extrapolated to other regions or situations. -100 -27 -28 -45 -31 -120 The CO2 emissions in the different cases modeled are presented in Figure 2. Both cases of biomass cofiring as well as -140 the CFB-Oxy-CCS offer significantly reduced emissions. It can be seen that significant emission reductions can be achieved CAPEX Fuel purchase (including subsidies and taxes) with CCS and high shares of biomass cofiring. Note that for CO2 allowances the energy penalty in CFB-Oxy-CCS case, the substitutive elec- CO transport and storage Substitutive electricity 2 tricity production is assumed to be produced by unabated Proﬁt Other operating costs coal-fired power; if the replacement electricity was provided by coal with CCS or some other blend of electricity, the carbon FIGURE 1. Annual operating costs and overall profits of footprint of the oxy-combustion case would be even lower. compared technologies (with default input values) in millions € per year If more aggressive climate policies are enacted in the future, including other targets for renewable energy and other com- The assumed fuel purchase prices were €10/MWh for coal and €20/MWh for biomass (based on LHV, including all costs petition for biomass (existing forest industry, targets for liquid biofuels, etc.), a significant increase in biomass prices could and taxes), €75/MWh for electricity, and a CO2 allowance of €35/tonne [an estimated future price that is higher than EU result, at least in areas where sustainable biomass availability Emissions Trading Scheme (EU ETS) trading values today]. is limited. Increasing biomass prices would result in coal-fired Peak load utilization rates of the plants were 7500 hours per year. The overall costs (capital and operating) and profits for Base Case Case I Case II Case III the four cases are presented in Figure 1. 2,000,000 The differences in electricity production, which can be attrib- 1,500,000 uted to the energy penalty in the CCS case, are taken into account as “substitutive electricity”, which enables the comparison of costs rather than annual cash flows, where income 1,000,000 from electricity would dominate the chart. From Figure 1 it can be determined that operation of the base-case coal-fired power 500,000 plant is the only option that is profitable under the economic assumptions made, although Case I with 30% biomass cofiring 0 0 is relatively close to the base case. Based on the economics -387,916 -500,000 and emissions assumed, break-even prices (BEP) for CO2 emission allowances in the EU ETS, at which specific cases become -911,389 favorable compared to the base case, were calculated. The -1,000,000 -914,307

BEPs were 46, 42, and 39 €/tonne CO2 for CFB-Oxy-CCS, 70% biomass cofiring, and 30% biomass cofiring, respectively. These -1,500,000 break-even points are a bit higher than, but generally in line Biogenic CO2 Fossil CO2 Replacement electricity with, estimates presented by Lüschen and Madlener for bio- Other Captured fossil CO2 9 mass cofiring with CO2 avoidance cost range of €25–32/tonne. CO2 emissions relative to base case

Note that if the modeling assumptions change, the model FIGURE 2. Categorized CO2 emissions for the four cases results vary dramatically. The most economical solution is modeled in tonnes per year

www.cornerstonemag.net 33 STRATEGIC ANALYSIS

oxy-combustion with CCS becoming economically advanta- of eight to 12 percentage points.11 Obviously, significant geous compared to biomass cofiring with large shares. improvements in reducing the energy penalty would be very helpful for the deployment of the CCS. One potential solution Based on our results, CFB oxy-combustion with CCS could to increase the efficiency (of all plants) is combined heat and become more competitive with quite realistic prices for bio- power, where over 90% process efficiency is achievable—if a mass and CO2 in the future. For example, with prices of €24/ large heat distribution system and relatively continuous heat MWh for biomass, €85/MWh for electricity, and €50/tonne consumption (or storage) in that system exist.12,13

CO2 allowance, the CFB-Oxy-CCS becomes the most profitable case modeled, although all are almost equally competitive.7 The costs associated with biomass cofiring are mainly due to the higher prices of biomass fuel in comparison to coal, higher IS CCS SUITABLE FOR BIOMASS COFIRED PLANTS? plant investment, and higher O&M costs. The use of biomass increases O&M costs of the cofiring retrofit plant through negative effects on the availability of the boiler (i.e., boiler- The cases discussed thus far reduced CO2 emissions, but did not eliminate them. An opportunity exists, however, for coal/ related issues cause increased plant downtime) and increased maintenance work and consumables. When considering a biomass cofiring with CCS to not only eliminate CO2 emissions, retrofit option for biomass, the feasibility of the investment but actually offer negative CO2 emissions. This approach could help reach climate targets by offsetting historical emissions and the willingness to invest are affected also by the remain- 5,14 and emissions from sectors with expensive or more difficult ing lifetime of the plant and the annual operating hours. An large-scale emission reductions (e.g., the transportation sec- indicative comparison on the CAPEX and operating expenses tor) in the near term. In general, similar solutions are suitable (OPEX) in coal, biomass, and cofired CFB boiler with and without CCS is presented in Figure 3. for capturing CO2 from applications utilizing biomass as for fossil fuels. The main differences relate to the different kinds of impurities in the combustion process: ash and flue gas. In The costs for CCS depend heavily not only on the characteris- principle, there are no technical restrictions for capturing bio- tics of the facility and the operational environment but also on the assumptions related to future operation. From an inves- genic CO2 via cofiring. However, the current EU ETS does not recognize negative emissions, and thus no economic incentive tor’s point of view, the optimal solution depends on multiple factors, electricity and EU ETS prices being the most domi- exists for capturing biogenic CO2 from installations combust- ing even partly biomass. nant. As far as capturing biogenic emissions (and achieving negative emissions) from power plants is concerned, the only Despite fluidized bed technology’s high flexibility regarding the realistic applications are facilities that cofire biomass with coal fuels, challenges exist in the case of biomass cofiring. Some of and implement CCS. Dedicated biomass-firing plants are not these challenges may be emphasized when CCS is employed considered to be the optimal sites to apply CCS in the initial at the plant. For example, with oxy-fired fluidized bed boilers phase as these facilities are likely smaller than fossil-fueled even small concentrations of chlorine from the biomass fuel facilities and do not currently need to reduce their CO2 emis- can lead to harmful alkaline and chlorine compound depos- sions. When discussing the biomass cofiring option, one must its on boiler heat transfer surfaces. This is because of lack of also address questions related to how availability of biomass nitrogen in furnace and the components’ increased concen- 7 trations as a result of flue gas recirculation. Fossil Fossil with Bio/Multi Bio/Multi with CO2 capture • Agro CO2 capture • Wood COFIRING, CCS, OR BOTH?

There are still technical and economic challenges restricting the application of biomass cofiring and CCS as emission reduction solutions. Both CCS and biomass cofiring offer pros and • High plant • 8 – 12%-pts eff. • Good plant • Efficiency penalty cons and their potential roles globally as carbon abatement efficiency penalty in CCS efficiency similar to fossil tools are not yet certain. Both technologies must reduce the • Fossil CO2 • Up to 95% CO2 • Zero (biogenic) • “Negative” CO2 emissions capture rates CO2 emissions emissions associated costs prior to widespread deployment. Lowest OPEX* Higher OPEX* Higher OPEX* Highest OPEX* and CAPEX and CAPEX than and CAPEX than and CAPEX The major costs associated with CCS result from equipment without capture with fossil fuels investment, loss of production due to the CCS energy penalty, FIGURE 3. An indicative comparison of the CAPEX and OPEX and transportation and storage of CO2. First-generation CCS in coal, biomass, and cofired CFB boiler with and without CCS technologies are expected to result in efficiency decreases *Without CO2 allowances

34 affects pricing and the competition for raw material between REFERENCES different users, such as the forest industry and liquid biofuel producers. 1. ZEP. (2012). Biomass with CO2 capture and storage (bio-CCS): The way forward for Europe, www.biofuelstp.eu/downloads/ bioccsjtf/EBTP-ZEP-Report-Bio-CCS-The-Way-Forward.pdf CONCLUSIONS 2. IEAGHG. (2011, July). Potential for biomass and carbon dioxide capture and storage. Report 2011/06, www.eenews.net/ assets/2011/08/04/document_cw_01.pdf The possible and predicted high economic value on CO2 emis- 3. Koljonen, T., et al. (2012). Low carbon Finland 2050. VTT clean sions as well as strict emission standards could provide a energy technology strategies for society. Espoo: VTT Technical foundation for the development and deployment of biomass Research Centre of Finland, www.ashraeasa.org/pdf/VTT%20 cofiring and CCS as individual or combined technologies. Both Low%20Carbon%20Vision.pdf options are applicable for existing and new power plants and 4. KEMA. (2009, July). Co-firing biomass with coal. Balancing US the technologies have already been demonstrated. Biomass carbon objectives, energy demand and electricity affordability. White paper. Burlington, MA: KEMA Inc. cofiring is the most efficient means of power generation from 5. Kärki, J., Flyktman, M., Hurskainen, M., Helynen, S., & Sipilä, K. biomass, and thus offers a CO2 avoidance cost lower than that (2011). Replacing coal with biomass fuels in combined heat and for CO2 capture from existing power plants—provided reason- power plants in Finland. In: M. Savolainen (Ed.), International ably priced carbon-neutral biomass is available. However, future Nordic Bioenergy 2011—Book of proceedings (pp. 199–206), policies on legislation, subsidies, and carbon accounting remain www.vtt.fi/inf/julkaisut/muut/2011/Finland_Karki.pdf 6. Nevalainen, T., Jäntti, T., & Nuortimo, K. (2012). Advanced CFB the most vital factors for successful biomass cofiring business. technology for large scale biomass firing power plants. Paper presented at Bioenergy from Forest, 29 August, Jyvaskyla, Finland, www.fwc.com/getmedia/227a6ef3-a052-42e4-b81e- ca642124869a/TP_FIRSYS_12_07.pdf.aspx?ext=.pdf “There is a path forward for neutral 7. Arasto, A., Tsupari, E., Kärki, J., Sormunen, R., Korpinen, T., & Hujanen. S. Feasibility of significant CO2 emission reductions in or even negative carbon emissions at thermal power plants—Comparison of biomass and CCS. GHGT- 12 (submitted 15 September 2014). 8. Tsupari, E., Kärki, J., & Arasto, A. (2011). Feasibility of BIO- power plants that combust coal.” CCS in CHP production—A case sudy of biomass cofiring plant in Finland. Presented in Second international Workshop on Biomass & Carbon Capture and Storage, 25-26 October, Cardiff, Wales. Economically, the difference between biomass cofiring and 9. Lüschen, A., & Madlener, R. (2013). Economic viability of CCS varies depending on site-specific circumstances. In gen- biomass cofiring in new hard-coal power plants in Germany. eral, however, the EU ETS price and electricity prices projected Biomass and Bioenergy, 57, 33–47, dx.doi.org/10.1016/j. in the near future do not yet make CCS investment feasible. biombioe.2012.11.017 10. Teir, S., et al. (2011). Hiilidioksidin talteenoton ja varastoinnin The economic viability of CCS in the EU is heavily dependent (CCS:n) soveltaminen Suomen olosuhteissa. Espoo, VTT. 76 s. + on the CO2 allowance price. liitt. 3 s. VTT Tiedotteita - Research Notes; 2576 ISBN 978-951- 38-7697-5; 978-951-38-7698-2. There is a path forward for neutral or even negative carbon 11. IEA. (2013). Technology roadmap: Carbon capture and storage, emissions at power plants that combust coal. For negative www.iea.org/publications/freepublications/publication/ technologyroadmapcarboncaptureandstorage.pdf net emissions, capturing biogenic emissions is a widely avail- 12. Davison J. (2007). Performance and costs of power plants with able option; power plants that cofire biomass with coal offer capture and storage of CO2. Energy, 32, 1163–1176. the greatest potential and most straightforward applications. 13. Kärki, J., Tsupari, E., & Arasto, A. (2013). CCS feasibility in However, the most important factors affecting the deploy- improvement in industrial and municipal applications by heat ment of the combined carbon-mitigation technologies include utilisation, Energy Procedia, 37, 2611–2621. 14. Basu, P., Butler, J., & Leon, M.A. (2011). Biomass co-firing options the availability of biomass, coal, and CO2 transportation and on the emission reduction and electricity generation costs in storage options as well as the political will (expressed through coal-fired power plants. Renewable Energy, 36(1), 282–288, carbon pricing and recognition of negative emissions) and dx.doi.org/10.1016/j.renene.2010.06.039 acceptance of the technologies. In reality, these technologies are already available and nearly ready to be demonstrated The authors can be reached at [email protected] and antti. and then deployed. [email protected]

www.cornerstonemag.net 35 STRATEGIC ANALYSIS

Evolution of Cleaner Solid Fuel Combustion

By Christopher Long study were based in the U.S. due to the larger amount of air Principal Scientist, Gradient modeling data available, but were older and had more limited emissions controls than modern state-of-the-art plants. Peter Valberg As a result, these plants are useful for representing the air Principal, Gradient exposure impacts of plants that might be built in developing countries today, including those built without international support for meeting high-efficiency, low-emissions standards.

lthough uncommon in developed countries, solid For our comparisons, we focused on air exposure concentra- A fuels—including wood, charcoal, coal, dung, and crop tions rather than emissions because possible exposure via Aresidues—are burned domestically by billions of people breathing cannot be characterized based solely on emissions across the world for space heating, lighting, and cooking. For data (e.g., tons per year), but rather needs to be assessed example, it is estimated that, as of 2010, approximately 41% of through examining concentrations of pollutants [masses of the world’s households (approximately 2.8 billion people) rely pollutants per unit volume of air—e.g., micrograms per cubic mainly on solid fuels for cooking.1 A comprehensive assess- meter (μg/m3)] that can potentially be inhaled. In addition, we ment of respiratory risks from household air pollution recently used an alternative metric of exposure, namely intake fraction concluded that the health of one in three people worldwide (iF), to supplement this analysis. is at risk because of exposure to emissions from traditional household solid fuel combustion.2

To provide some perspective on their relative air exposure “As compared to traditional impacts, we have compared exposure of people to traditional household solid fuel combustion emissions (e.g., smoke household solid fuel combustion from domestic burning of biomass material or coal) to those of coal-fired power plants (CFPPs). We used data from pub- … modern coal-fired power plants lished papers and reports and tabulated levels of people’s exposure to common air pollutants from these two different represent a more sophisticated and combustion sources. The coal-fired power plants used for the cleaner approach to getting the maximum energy out of solid fuel…”

ASSESSMENT OF REPORTED AIR EXPOSURE LEVELS

Traditional Household Solid Fuels Contribute to Complex Indoor Air Pollution

Over the past several decades, numerous studies have investigated the air pollution generated by traditional household solid fuel combustion for space heating, lighting, and cooking in A review of available literature has shown that traditional developing countries.1,3 It is now well established that, through- stoves for cooking and heating are a much more inefficient out much of the world, indoor burning of solid fuels (e.g., wood, and dangerous means of energy utilization compared to charcoal, coal, dung, and crop residues) by inefficient, often modern electricity services. insufficiently vented, combustion devices (e.g., ovens, stoves,

36 TABLE 1. Summary of indoor PM2.5 and CO breathing zone exposure levels in developing-country households with traditional household solid fuel combustion3

3 3 Number of Total Number PM2.5 (μg/m ) CO (mg/m ) Location Studies of Samples meal avg. daily avg. meal avg. daily avg. Bangladesh 1 53 15–26 Burundi 1 2 42 Ethiopia 1 NA 48 Ghana 1 21 9 Guatemala 7 768 450–27,000 97–1900 2–149 1.2–17 India 13 1009 110–2100 1300–1500 5–216 Kenya 4 199 630–3500 5–60 Malaysia 1 10 3 Mexico 5 191 890 10–22 Mozambique 1 114 48 Nepal 5 127 1700–5700 14–360 14–52 New Guinea 1 9 13–24 Nigeria 1 28 1076 South Africa 1 20 79–180 92 Zambia 1 89 10

Notes: NA = not available. Meal avg. = average concentrations measured during active meal and cooking times, typically between 30 minutes and three hours. or fireplaces) leads to highly elevated exposures to household combustion and are considered to pose the greatest health air pollutants. This is due to the poor combustion efficiency of risks.2 Table 1, adapted from Naeher et al.,3 summarizes indoor the combustion devices and the elevated nature of the emis- air measurements of PM2.5 and CO associated with traditional sions; moreover, they are often released directly into living household solid fuel combustion. As shown in the table, PM2.5 areas.3 Smoke from traditional household solid fuel combustion exposure levels have been consistently reported to be in the commonly contains a range of incomplete combustion prod- range of hundreds to thousands of micrograms per cubic ucts, including both fine and coarse particulate matter (e.g., meter (μg/m3); likewise, CO exposure levels as high as hun-

PM2.5, PM10), carbon monoxide (CO), nitrogen dioxide (NO2), dreds to greater than 1000 milligrams per cubic meter (mg/ 3 sulfur dioxide (SO2), and a variety of organic air pollutants (e.g., m ) have been measured. Consistent with these data, a more formaldehyde, 1,3-butadiene, benzene, acetaldehyde, acrolein, recent study of 163 households in two rural Chinese counties phenols, pyrene, benzopyrene, benzo(a)pyrene, dibenzopy- reported geometric mean indoor PM2.5 concentrations of 276 3 renes, dibenzocarbazoles, and cresols).2 In a typical solid fuel μg/m (combinations of different plant materials, including 3 stove, approximately 6–20% of solid fuel mass is converted into wood, tobacco stems, and corncobs), 327 μg/m (wood), 144 3 3 toxic emissions, with such factors as the fuel type and moisture μg/m (smoky coal), and 96 μg/m (smokeless coal) for homes content, stove technology, and stove operation influencing the using a variety of different fuel types and stove configurations 4 amount and relative composition of the pollution mixture.1 (vented, unvented, portable, fire pit, mixed ventilation stove).

Even though the mixture of pollutants arising from traditional Air Modeling of CFPP Emissions Predicts household solid fuel combustion is complex, most measure- Substantially Lower Air Quality Impacts ment studies have focused on characterizing breathing-zone exposure levels of two surrogate species in solid fuel smoke, In comparison to traditional solid fuels, CFPP emissions are namely PM and CO, which are the main products of incomplete associated with far lower ground-level ambient exposure levels

www.cornerstonemag.net 37 STRATEGIC ANALYSIS

B of both PM2.5 and CO. Table 2 provides a summary of model- the majority of the modeled plants are older CFPPs that lack the predicted ground-level PM2.5 and CO concentrations from clean coal technologies characteristic of newer and retrofitted publicly available studies of the ambient air quality impacts CFPPs. With respect to PM, these studies generally accounted for of U.S. CFPPs. We relied on model-predicted concentrations both primary PM2.5 emissions and secondary atmospheric forma- rather than measurement data because air-monitoring data tion of sulfate and nitrate particles from gaseous SO2 and NOx are not specific to power plant emissions and include con- emissions, respectively. With respect to CO, we identified just a tributions from a variety of other common anthropogenic, single modeling study that predicted the CO air quality impacts of natural, and distant air pollution sources. As indicated in Table 2, emissions from CFPPs (as well as a number of natural gas power all but one of the studies we identified reflect modeled air qual- plants).5 Most likely because CO emissions from U.S. CFPPs are ity impacts for groups of U.S. CFPPs in the same general vicinity; low and not considered to pose significant air quality problems thus, these data encompass air quality impacts higher than what or public health impacts, CO has not received as much attention 6 would be the case for a single newer U.S. power plant. Moreover, as PM2.5 in studies of the air quality impacts of power plants.

a,b TABLE 2. Model-predicted ground-level PM2.5 and CO concentrations associated with U.S. CFPP emissions

Model-Predicted Model-Predicted Number of Plant Capacity/ Ground-Level Annual Ground-Level Annual Source Modeled Plant Location(s) Characteristics Average PM Air Conc. Average CO Air Conc. CFPPs 2.5 (µg/m3) a (mg/m3) a

805-MW nameplate 0.2 for maximum po- Salem, capacity; older plant tential plant emissions, 1 Massachusetts, NA grandfathered under including both primary U.S. Clean Air Act and secondary PM Levy et al. 2.5 (2000)7 1611-MW nameplate 0.25 for maximum po- Somerset, capacity; older plant tential plant emissions, 1 Massachusetts, NA grandfathered under including both primary U.S. Clean Air Act and secondary PM2.5

>7500-MW total Illinois, in close nameplate capacity; 0.7, including both Levy et al. proximity to or 9 all older plants grand- primary and secondary NA (2002)8 upwind of the fathered under the PM Chicago area, U.S. 2.5 Clean Air Act

>13,000-MW total 0.6–0.9 depending on nameplate capacity; the air modeling ap- Levy et al. Georgia, in the 7 all older plants grand- proach, including both NA (2003)9 Atlanta area, U.S. fathered under the primary and secondary

Clean Air Act PM2.5

3 coal 1425-MW capac- Bexar County, 0.16 for year 2002 emis- plants/units ity for 3 coal plants/ Perkins et al. Texas, in the San sions, including both 0.00011 for year 2002 (and 18 units (and ~2300-MW (2009)5 Antonio metro- primary and secondary emissions gas plants/ capacity for 18 gas politan area, U.S. PM units) plants/units) 2.5

Notes: NA = not available. a As mentioned in the text, model-predicted ground-level annual average PM2.5 and CO air concentrations are generally for groups of older U.S. CFPPs due to the availability of air modeling studies; air concentrations for single U.S. CFPPs, and particularly newer, more advanced CFPPs, would be expected to be lower. On the other hand, air quality impacts of low-efficiency, uncontrolled CFPPs, such as those present in developing countries lacking stringent regulations, may be comparable, if not larger, than those in the table. b Some concentrations are for maximum impacted model receptor locations,8,9 while others are either population-weighted average concentrations7 or county- average impacts.5

38 The annual average ambient PM2.5 and CO concentrations Relative Intake Fractions for Traditional in Table 2 are far below the comparable daily-average PM2.5 Solid Fuel Combustion Versus CFPPs and CO indoor exposure levels associated with traditional C 11 iF household solid fuel combustion in Table 1. For PM2.5, sev- We identified just a single study that reported s for both eral studies7–9 of groups of older, grandfathered U.S. CFPPs types of PM combustion emissions. Smith (1993) estimated predicted annual average concentrations of less than 1 μg/m3 iFs ranging from approximately one to two one-thousandths for maximally impacted locations, as compared to daily aver- for PM emissions from traditional solid fuel combustion in biomass cookstoves versus substantially lower iFs of one one- age PM exposure levels of hundreds to thousands of μg/ 2.5 millionth for a U.S. CFPP and 10 one-millionths for a CFPP in a m3 inside homes with traditional solid fuel combustion. For least developed country (LDC) based on the assumption of a CO, the single modeled estimate that we identified for 2002 greater population density. In other words, these results indi- county-average CO impacts from three CFPPs/units (plus 18 cate that about one one-thousandth of what is released from gas-fired power plants/units) in the San Antonio, TX, metro- traditional household solid fuel burning is inhaled, while only 5 politan area is over 10,000 times lower than the lowest CO about one one-millionth of what is released from a U.S. CFPP exposure levels we found for traditional household solid fuel is inhaled. combustion (Table 1). These differences demonstrate the critical role of the proximity of the emission source to people in determining its exposure potential; whereas CFPP emissions are typically released from INTAKE FRACTION AS AN ALTERNATIVE tall stacks often far from heavily populated areas, emissions COMPARISON TOOL from traditional household solid fuel combustion in developing countries are often released directly into poorly ventilated Defining Intake Fraction indoor spaces (e.g., kitchens), where they can remain trapped for extended periods of time in direct proximity of people. The iF is a well-established metric in the exposure assessment Smith12 has subsequently emphasized the concept that the and public health fields for quantifying the emission-to-intake “place makes the poison”. relationship, in large part becauseiF s facilitate comparisons of the exposure implications of various emission sources. Intake More recent iF estimates for PM emissions from both tradi- fraction can be defined simply as the fraction of material emit- tional household solid fuel combustion and CFPPs confirm that iF differences between these sources span several ted into the air from a given source that is actually inhaled; orders of magnitude.9,13,14 For example, Levy et al.9 estimated however, Bennett et al.10 provided a more thorough defini- a slightly smaller iF for primary PM emissions from seven iF 2.5 tion of as “the integrated incremental intake of a pollutant, older northern Georgia (U.S.) CFPPs (0.0000006), and even summed over all exposed individuals, and occurring over smaller iFs for secondary sulfates and nitrates (0.0000002 and a given exposure time, released from a specified source or 0.00000006). In contrast, Grieshop et al.14 estimated iFs of sources, per unit of pollutant emitted.” It is generally reported 0.0013 and 0.00024 for unvented and outdoor-vented cook- as a unitless value, as expressed in the following equation10: stoves, respectively.

CONCLUSIONS ∑people, individual pollutant intake (mass, grams) iF = time mass released into the environment (mass, grams) We found that measured PM2.5 and CO concentrations inside homes burning traditional solid fuels are thousands of times greater than even the high-end estimates of ground-level ambient exposure levels from U.S. coal-fired power plant iF thus sums pollutant intake over two measures—population stack emissions. Even if a low-efficiency coal-fired power size and time duration—and incorporates a variety of factors plant with no emissions controls were employed—a likely related to the emission scenario and exposure conditions. scenario in areas where traditional solid fuels are combusted These factors include chemical properties of the contaminant, and in the absence of international support for efficiency emissions locations (e.g., release height, indoor versus- out and environmental upgrades—order-of-magnitude differ- door, proximity to people), environmental conditions (climate, ences would likely be observed compared to traditional meteorology, land use), human receptor locations and activi- solid fuel combustion. Moreover, we saw similar, support- ties, and population characteristics. Intake fractions canbe ing results using an alternative comparison approach based based on both modeling results and measurements. on intake fractions. Overall, these conclusions point to

www.cornerstonemag.net 39 STRATEGIC ANALYSIS

traditional household solid fuel combustion being a signifi- REFERENCES cantly greater source of air pollution exposures of health concern. The basic difference is that coal-fired power 1. Smith, K.R., Bruce, N., Balakrishnan, K., Adair-Rohani, H., Balmes, J., Chafe, Z., … HAP CRA Risk Expert Group. (2014). Millions plants burn coal much more efficiently and completely— dead: How do we know and what does it mean? Methods used and exhaust their emissions from tall stacks rather than in in the comparative risk assessment of household air pollution. direct proximity to people. Overall, as compared to tradi- Annual Review of Public Health, 35, 185–206. 2. Gordon, S.B., Bruce, N.G., Grigg, J., Hibberd, P.L., Kurmi, O.P., tional household solid fuel combustion, which represents Lam, K.B., … Martin, W.J., II. (2014). Respiratory risks from an inefficient, high-emission form of fuel utilization, mod- household air pollution in low and middle income countries. The ern coal-fired power plants (and even older ones with more Lancet Respiratory Medicine, epub ahead of print. 3. Naeher, L.P., Brauer, M., Lipsett, M., Zelikoff, J.T., Simpson, C.D., limited air pollution controls) represent a more sophisti- Koenig, J.Q., & Smith, K.R. (2007). Woodsmoke health effects: A cated, cleaner approach to getting the maximum energy review. Inhalation Toxicology, 19, 67–106. out of solid fuel with significantly reduced impacts on the 4. Hu, W., Downward, G.S., Reiss, B., Xu, J., Bassig, B.A., Hosgood, H.D. III, & Lan, Q. (2014). Personal and indoor PM2.5 exposure air that humans breathe. from burning solid fuels in vented and unvented stoves in a rural region of China with a high incidence of lung cancer. Environmental Science & Technology, 48, 8456–8464. NOTES 5. Perkins, J., Heilbrun, L., Symanski, E., Coker, A., & Eggleston, K. (2009). A study to evaluate the health effects of air pollution A. Although coal is used both for traditional household solid fuel in Bexar County with a focus on local coal and gas fired power combustion and for electricity generation at modern power plants. CPS Energy, www.cpsenergy.com/files/Health_Study_ plants, coal handling and combustion conditions for the two situ- FullReport.pdf 6. United States Environmental Protection Agency (U.S. EPA). ations are quite different. When used as a traditional household (2010). Integrated Science Assessment for Carbon Monoxide. solid fuel, large chunks of often lower-quality coal are directly EPA/600/R-09/019F. Research Triangle Park, NC: National Center burned under uncontrolled combustion conditions, such that for Environmental Assessment-RTP Division. combustion is inefficient and incomplete. In contrast, modern 7. Levy, J., Spengler, J.D., Hlinka, D., & Sullivan, D. (2000). Estimated power plants often burn higher-quality coal, usually pulverized public health impacts of criteria pollutant air emissions from and mixed with air, under efficient and controlled conditions, the Salem Harbor and Brayton Point power plants. Boston, MA: resulting in nearly complete combustion of coal organics. Harvard School of Public Health, Dept. of Environmental Health. B. Actual personal exposures to ambient-derived pollutants can 8. Levy, J.I., Spengler, J.D., Hlinka, D., Sullivan, D., & Moon, D. (2002). Using CALPUFF to evaluate the impacts of power often be significantly lower than ambient (outdoor) air exposure plant emissions in Illinois: Model sensitivity and implications. levels. This is largely because people in countries such as the Atmospheric Environment, 36, 1063–1075. U.S. spend the majority (~90%) of their time indoors where the 9. Levy, J.I., Wilson, A.M., Evans, J.S., & Spengler, J.D. (2003). infiltration process can result in significantly reduced concentra- Estimation of primary and secondary particulate matter intake tions indoors compared to the corresponding ambient levels fractions for power plants in Georgia. Environmental Science & outdoors. Technology, 37, 5528–5536. C. Although expressed for different averaging periods, the annual 10. Bennett, D.H., McKone, T.E., Evans, J.S., Nazaroff, W.W., Margni, average PM and CO concentrations shown in Table 2 (for M.D., Jolliet, O., & Smith, K.R. (2002). Defining intake fraction. 2.5 Environmental Science & Technology, 36, 207A–211A. power plants) should be compared to the daily average PM 2.5 11. Smith, K.R. (1993). Fuel combustion, air pollution exposure, and and CO concentrations in Table 1 (for traditional household solid health: The situation in developing countries. Annual Review of fuel combustion), which would occur repeatedly on a daily basis. Energy and the Environment, 18, 529–566. That is, the daily average PM2.5 and CO concentrations in Table 1 12. Smith, K.R. (2002). Place makes the poison – Wesolowski Award can be assumed to be representative of long-term average (e.g., Lecture – 1999. Journal of Exposure Analysis and Environmental annual average) exposure levels given the daily occurrence of Epidemiology, 12, 167–171. solid fuel combustion for cooking, heating, and lighting. 13. Evans, J.S., Wolff, S.K., Phonboon, K., Levy, J.I., & Smith, K.R. (2002). Exposure efficiency: An idea whose time has come? Chemosphere, 49, 1075–1091. ACKNOWLEDGEMENTS 14. Grieshop, A.P., Marshall, J.D., & Kandlikar, M. (2011). Health and climate benefits of cookstove replacement options. Energy Policy, 39, 7530–7542. This article was commissioned by Peabody Energy; it reflects the professional opinions of the authors and the writing is The authors can be reached at [email protected] and solely that of the authors. [email protected]

40 TECHNOLOGY FRONTIERS

Making Coal Flexible: Getting From Baseload to Peaking Plant

By Jaquelin Cochran We have used a case study of this CGS to evaluate how power Senior Energy Analyst, plants intended to run at baseload can evolve to serve other National Renewable Energy Laboratory (NREL) system needs. The CGS case illustrates the types of changes that may occur in global power systems, especially those Debra Lew with legacy plants. CGS’s experiences challenge conventional Independent Consultant wisdom about the limitations of coal-fired power plants and help policymakers better understand how to formulate policy Nikhil Kumar and make investment decisions in the transformation toward Director of Energy & Utility Analytics, Intertek power systems in a carbon-constrained world.

ower systems in the 21st century—with higher penetration “Strategic modifications, proactive of low-carbon energy, smart grids, and other emerging Ptechnologies—will favor resources that have low marginal inspections and training programs, costs and provide system flexibility (see Figure 1). Such flexibility includes the ability to cycle on and off as well as run at low and various operational changes to minimum loads to complement variations in output from high penetration of renewable energy. With a lack of general experi- accommodate cycling can minimize ence in the industry, questions remain about both the fate of coal-fired power plants in this scenario and whether they can the extent of damage and minimize continue to operate cost-effectively if they cycle routinely. cycling-related maintenance costs.” To demonstrate that coal-fired power plants can become flexible resources, we discuss experiences from an actual multi-unit North American coal generating station (CGS).A,1 This flexibility—namely, the ability to cycle on and off and run at below 40% A BRIEF HISTORY OF THE CGS PLANT of capacity—requires limited modifications to hardware, but extensive modifications to operational practice. Cycling does When it came online in the 1970s, the CGS plant was intended damage the plant and impact its life expectancy compared to to run at an 80% annual capacity factor. However, the addi- baseload operations. However, strategic modifications, proac- tion of nuclear power soon thereafter displaced coal as the tive inspections and training programs, and various operational principal source of baseload generation. Consequently, CGS changes to accommodate cycling can minimize the extent of typically ran at 50% annual capacity factor until the early damage and minimize cycling-related maintenance costs. 1990s. To understand the effects of “two-shifting” (i.e., cycling on and off in a day) considerable research was conducted in Curtailment 100 Wind the 1980s. As a result, plant operations, the steam generator, PV and supporting equipment were modified. 75 CSP Storage Other 50 Gas CT After a competitive market was introduced in the early 2000s, Gas CC the CGS plant was operated for longer periods at full plant Hydro 25 Geothermal output—this period was also marked by significant forced out- Generation (GW) Generation Coal ages. For example, in 2004, the equivalent forced outage rate 0 Nuclear Mar 25 Mar 26 Mar 27 Mar 28 Mar 29 Mar 30 Mar 31 Apr 01 (EFOR)—a measure of a plant’s unreliability—was 32%, which FIGURE 1. Simulated dispatch of generation over one week represented the accumulated latent damage from the cycling in a high renewable energy scenario (annual load served by that CGS performed in the 1990s. Typical EFOR for a baseload 2 25% wind, 8% solar photovoltaic). coal-fired power plant is 6.4%. Notes: PV = solar photovoltaic; CSP = concentrated solar power; CT = combustion turbine; CC = combined cycle The competitive market created the incentive for CGS units to Source: Lew et al., 2013 continue to operate flexibly—for example, that they be able to

www.cornerstonemag.net 41 TECHNOLOGY FRONTIERS

thermal stresses within single components and between different components when materials heat at different rates.

Other typical effects of cycling and operating at low loads include:

• Stresses on components and turbine shells resulting from changing pressures • Wear and tear on auxiliary equipment used only during cycling • Corrosion caused by oxygen entering the system during start-up and by changes in water quality and chemistry • Condensation from cooling steam during ramping down and shutting down, which can cause corrosion of parts, water leakage, and an increased need for drainage

FIGURE 2. Example of large nick in turbine fin (#96) due to impact These effects (summarized in Table 1) can cause equipment with dislodged material formed by oxidation (Debra Lew) components, particularly in the boiler, to fatigue and fail. In turn, equipment failure leads to increased outages, increased opera- two-shift and operate at an output below intended minimum tions and maintenance (O&M) costs, additional wear and tear load. Although the two- and sometimes four-shifting created from the increased O&M, and more extensive and sophisticated wear and tear and reduced the plant’s cost competiveness, training, inspection, and evaluation programs.3 The damage the CGS owners operated the plant in this fashion to compete from cycling is not immediate—for example, components may in the wholesale power market. fail and EFOR may rise a few years after significant cycling.

EXAMINING THE IMPACT OF CYCLING AT CGS MODIFYING THE PHYSICAL PLANT AND OPERATING PROCEDURES The CGS coal units were intended to primarily run at full output and start cold only a few times a year. However, each CGS coal- Physical Modifications fired unit has experienced an average of 1760 starts, including 523 cold starts throughout its lifetime. The overarching effect The CGS plant owner made numerous physical modifications of this type of cycling is thermal fatigue. For example, large to equipment to prevent and address impacts from cycling and temperature swings from cold feedwater entering the boiler low-load operations. These changes have focused on actions on start-up and from steam as it is heating create fluctuating that improve drainage and thermal resiliency and reduce

TABLE 1. Specific experiences from cycling at CGS

Problem Impact/Cause

Failure of boiler tubes Caused by cyclic fatigue, corrosion fatigue, and pitting Cracking in dissimilar metal Due to rapid changes in steam temperature welds, headers, and valves Due to movement between the rotor and casing during “barring” Cracking of generator rotors (slow turns to keep rotors from being left in one position too long during turning-gear operation) Oxidation from exposure to Oxides in boiler tubes can dislodge due to thermal changes and air on start-up and draining lead to damage downstream, such as the turbine blades (see Figure 2) From oxides, but also from wet steam that occurs on start-up, during Corrosion of turbine parts low-load operations, and during poor plant storage conditions when the plant is dried

Condenser problems Can occur when thin tubes crack from thermal stresses at start-up and shutdown

42 opportunities for corrosion, as described in Table 2. There were from cycling. Training programs to reinforce the skills needed no major capital retrofits to allow additional cycling flexibility. to monitor the impacts of cycling were also central to the CGS owner’s strategy. Decisions on whether and when to replace parts or modify components were made on a case-by-case basis. In other words, A LOOK AT COSTS AND EMISSIONS the plant owner based such decisions on whether wholesale power market opportunities in the coming year justified the The costs associated with cycling, and modifications made cost of modifications to reduce the forced outage rate. in response, are difficult to distinguish from normal operation efforts. Modifications were made over the course of Operating Procedures decades, in response to both cycling and noncycling wear and tear, to achieve EFOR rates that varied highly by unit and The owner of CGS estimates that once the physical changes year. Extrapolating cost implications to other coal-fired power were in place, 90% of future cost savings came from modifying plants generally from the experiences at CGS is difficult due to operating procedures. For example, establishing procedures variations in age, design, and history of operations. Moreover, and training on boiler ramp rates was especially effective. decisions on the scope and timing of modifications depend Controlled ramp rates help minimize thermal fatigue; continual on business case justifications, which are highly market- and reinforcement of the importance of controlled ramping through context-driven and could vary from year to year. training helps ensure that ramp rate procedures are followed. Studies of coal-fired power plants, such as Kumar et al.,5 evalu- Another example of effective modifications to operating pro- ate cycling costs by calculating operating, maintenance, and cedures is high-energy (i.e., high temperature or pressure repair costs associated with cycling. The plants in this study steam) piping inspections, the value of which is not always represent typical operations where coal-fired power plants appreciated at other coal-fired power plants. The inspection are operated and maintained according to baseload require- program at CGS covers all the failure mechanisms that can ments. However, the CGS plant owner recognized early on that occur (e.g., thermal and corrosion fatigue), and establishes a CGS would be cycling significantly and, therefore, modified repair process and a repair program for each failure mecha- operating practices and equipment to minimize the impacts of nism. The owner employs many similar inspection programs, cycling. Thus, because of the owner’s proactive changes, the for example, for the hanger rods that hold the high-energy costs to mitigate cycling based on EFOR rates at CGS are likely piping. These examples illustrate that effective operating pro- less than those for other plants with similar cycling and EFOR cedures require an understanding of all components impacted rates whose owners are not as proactive. by cycling—not just the major ones. Table 3 describes some of the modifications that were made to CGS’s operating proce- Cycling also incurs costs associated with increased emissions dures to support cycling. rate. The selective catalytic reduction (SCR) system, which controls some emissions, must be operated at a minimum load. Changes to plant operating procedures were critical to However, if a power plant needs to operate below this level, enabling CGS to cycle on and off cost-effectively. Controlling the owners may have authority to run the plant without the the rise in temperatures during plant start-up and temperature SCR system, as is the case with CGS. Other emissions impacts drops on shutdowns as well as having rigorous inspection pro- occur due to increased fuel use at start-ups, reduced plant grams for major and minor components limited the damage efficiency at less than full load, and reduced effectiveness

TABLE 2. Examples of physical modifications to support cycling

Added a metal overlay to water walls to minimize oxidation, cut back membranes in various areas to reduce Boiler start-up stresses, and replaced dissimilar metal welds. Added drains, upgraded the lubrication system, modified vacuum pumps and low-pressure crossover bellows, Turbines and inspected the non-return valves, which can be damaged during shutdowns. Generator Insulated and epoxied key parts to reduce rotor cracking from rubbing and established continual tests and Rotors checks to monitor trends. Plugged tubes at the top of the condenser that had been damaged as a result of low-load operation and Condenser water impingement, reducing overall efficiency; also installed stainless-steel air removals and retubed the existing brass on several units.

www.cornerstonemag.net 43 TECHNOLOGY FRONTIERS

TABLE 3. Example modifications to operating procedures to support cycling

Accelerated forced cooling for the boiler enabled the owner to quickly shut down the unit to repair a boiler tube and be back online in two days. However, after a year of implementing accelerated Natural cooling forced cooling, the units recorded a noticeable increase in corrosion and cyclic fatigue failures. The shutdown procedures are now to keep the boiler shut for the first four hours (natural cooling).

Economizer inlet headers can crack from intermittent additions of cold feedwater to the hot inlet Monitoring economizer header. The plant owner keeps the temperature difference between the header and water at less inlet headers than 30°C, below the boiler manufacturer recommendations.4 Pressure part The owner established a pressure-part management program, reviewing every pressure management component and establishing causes for degradation and failure. These included a program to monitor boiler metal temperature; a tube replacement and Other changes to boiler inspection strategy; a thermal and cyclic fatigue inspection and repair program; a fly-ash erosion operating procedures program to reduce tube failures; and inspection programs for expansion joints, dissimilar metal welds, and flow-accelerated corrosion. The owner established training and monitoring procedures, with associated monitoring Temperature monitoring equipment, to limit ramp rates and to monitor temperature changes to thick-walled fittings, for turbine parts headers, and the casing to the main steam line. To reduce corrosion, proper water chemistry must be maintained to protect surfaces that oxidize. Water chemistry Water chemistry varies with cycling, so the owner maintains a chemistry staff onsite maintenance and established a Chemistry Managed System (following ISO standards). Overall monitoring The owner compared reports on best practices associated with cycling with CGS’s equipment programs status and mitigating actions and created an overall plant monitoring program. of pollution-control equipment when flue gas temperatures boiler to reduce thermal shocking of tubes in the boiler. In con- at start-up are too low to support the chemical reactions trast, almost all other boilers in North America are a “pendant needed.6 Although emissions rates during cycling can be design”, which results in water accumulating at the bottom of higher than during noncyclic operation, Lew et al.6 showed the U-shape and leading to slow drainage. This design cannot that the avoided emissions from the added wind and solar far be modified, although a $10–15-million bypass system could be outweigh the impacts of cycling-induced emissions. added to improve temperature control and reduce tube failure.

CAN THE CGS EXPERIENCE BE REPLICATED? Automation of CGS’s drainage system, absent in most coal- fired power plants, was also critical to reducing failures. Earlier The CGS plant achieved the flexibility to cycle over several in plants’ projected lifetimes, such major retrofits could be decades; this experience has provided valuable information economically feasible. on impacts, recommended modifications to operations and equipment, and relative costs. However, some of the aspects Operating Distinctions of CGS that improve the plant’s flexibility might not easily translate to other contexts. CGS experiences much higher EFOR rates than typically accommodated in markets where coal-fired power plants run Physical Distinctions at baseload. The plant owner can manage these high EFOR rates because of the role CGS’s coal-fired units play in its sys- Some of CGS’s original plant designs are conducive to cycling— tem operations. The owner found that EFOR rates could be the owner did not need to conduct major-capital retrofits. For reduced by being highly proactive with inspections and strate- example, CGS’s boiler tubes are horizontal, which facilitates gic operational modifications. cycling by improving drainage; this reduces corrosion fatigue and the time needed to come back online (see Figure 3). Effective However, a trade-off between maintenance costs and EFOR operating practice requires drainage of any residual water in the rates exists. Grid operators may need to change how they

44 operate their systems, and coal-fired power plant operators Gas Flow may require a cultural shift to adapt to higher EFORs. This is particularly true because justifying maintenance costs over EFOR rates could become increasingly difficult if the cost per Gas Flow unit of energy generated increases at low load.

Regulatory Distinctions

Operating at low generation levels could be challenging if plants are required to run environmental controls at all output Pendant Design Horizontal Design levels. Operating an SCR system requires a minimum generating level that is frequently higher than the low generating FIGURE 3. CGS has a horizontal, not pendant, boiler design, levels at which the CGS plant owner is permitted to operate. which facilitates drainage needed to reduce corrosion fatigue and allow the plant to come online faster. The pendant design more easily allows water accumulation. (Graphic: FROM BASELOAD TO PEAKING PLANT Steve Lefton, Intertek)

At CGS, the plant owner has achieved what few coal-fired NOTES power plant operators have been able to do: modify a plant that was intended to run only at baseload into one that can A. For commercial reasons the CGS is not further identified. meet peak demands—cycling on and off up to four times a day to meet morning and afternoon electricity demand. Key to ACKNOWLEDGMENTS the owner’s success is changing operational practices: monitoring and managing temperature ramp rates; creating a suite This publication was produced under direction of stthe 21 of inspection programs for all impacted equipment (large and Century Power Partnership by the National Renewable Energy small); and continual training to reinforce the skills needed in Laboratory (NREL) under Interagency Agreement DE-AC36- monitoring and inspections. 08GO28308 and Task Nos. WFH1.2010 and 2940.5017.

The owner’s success in cycling has also benefited from factors REFERENCES specific to CGS. The original plant design, although intended for baseload operation, included features that facilitate cycling. 1. Cochran, A., Lew, D., & Kumar, N. (2013). Flexible coal: Evolution Although the cycling features were an advantage for the unit’s from baseload to peaking plant, NREL Report No. BR-6A20-60575. operating regime, additional modifications and procedural Golden, CO: National Renewable Energy Laboratory. www.nrel. changes were required to improve equipment reliability. gov/docs/fy14osti/60575.pdf 2. Vuorinen, A. (2007). Planning of power system reserves, www. optimalpowersystems.com/stuff/planning_of_power_system_ Also, the decades-long practice in cycling has increased the reserves.pdf owner’s tolerance for rates of forced outages that are higher 3. Electric Power Research Institute. (2001). Damage to power than those that are typical for plants required for baseload. plants due to cycling. Product ID 1001507. Palo Alto, CA: EPRI. www.epri.com/abstracts/Pages/ProductAbstract.aspx?Product Id=000000000001001507 The ability of other coal-fired power plant operators to repli- 4. Babcock & Wilcox. (1994). Economizer inlet header cracking. cate CGS’s flexibility will be instrumental in valuing coal in an www.babcock.com/library/pdf/PSB-22.pdf increasingly low-carbon energy system. Although the CGS unit 5. Kumar, N., Besuner, P., Lefton, S., Agan, D., & Hilleman, D. has certain inherent design features that assist in its operating (2012). Power plant cycling costs. NREL/SR-5500-55433. Work mode, retrofits and operational modifications to other coal- performed by Intertek-APTECH, Sunnyvale, California. Golden, CO: NREL. www.nrel.gov/docs/fy12osti/55433.pdf fired power plants can allow for increased flexible generation 6. Lew, D., et al. (2013). The Western Wind and Solar Integration Study across many power systems. Coal-fired power plants can Phase 2. NREL/TP-5500-55588. Golden, CO: National Renewable cycle, and if designed and operated appropriately, can provide Energy Laboratory. www.nrel.gov/docs/fy13osti/55588.pdf flexibility, sometimes more significantly than even CGS. There is a cost to cycle and also increased risk of unavailability, but The authors can be reached at [email protected], this is true for other types of generation as well. [email protected], and [email protected]

www.cornerstonemag.net 45 TECHNOLOGY FRONTIERS

Geothermal Assisted Power Generation for Thermal Power Plants

By Nigel Bean utilizing unconventional geothermal resources. As coal-fired Chair of Applied Mathematics, power plants rarely exist near conventional (hydrothermal, School of Mathematics, University of Adelaide volcanogenic) geothermal resources, some have drawn the incorrect conclusion that GAPG is of little value or can only Josephine Varney be applied in rare cases. However, the development of uncon- Ph.D. Candidate, University of Adelaide ventional (nonhydrothermal, nonvolcanogenic) geothermal resources offers the potential for geothermal energy tobe exploited over a much larger geographic range. Therefore, we believe that GAPG should be strongly considered as a means he recent push to reduce carbon emissions from the for integrating conventional energy with renewable energy in electricity sector encompasses common, immediately Tavailable approaches such as increasing power plant the most efficient manner possible. efficiency and increasing the deployment of renewables. The opportunity now exists to accomplish these goals simultaneously through the use of geothermal energy to increase the “Up to three times as much power power output, and decrease the carbon intensity, of thermal power plants. This technology is referred to here as geothermal can be generated per kilogram of assisted power generation (GAPG). Basically, GAPG employs hot geothermal fluid to heat the boiler feedwater at a thermal geothermal fluid as can be achieved power plant. The steam that would otherwise be taken from the turbines to heat the feedwater is allowed to run through in a stand-alone geothermal plant.” the turbines, thereby generating extra power and increasing plant efficiency. Here we use efficiency to mean “fossil fuel efficiency”, as more power is generated per unit heat (MMBtu) of fossil fuel, because of the addition of the geothermal heat. UNCONVENTIONAL GEOTHERMAL RESOURCES

Not only would this technology increase the efficiency of exist- Geothermal energy has been defined as “utilizable heat from ing thermal power plants, most of which are coal fired, it would the earth”.1 Given that the earth’s temperature increases with also assist the development of the immature technology of depth below the surface, geothermal energy exists everywhere. Further, since it is possible to use geothermal energy to generate power, it has the potential to be a renewable, carbon-free source of baseload electricity. However, while geothermal energy exists everywhere, the cost of extracting this energy does not make it commercially viable everywhere. To be commercially viable a geothermal resource must have sufficient temperature and flowrate that can be accessed relatively simply.

Conventional geothermal resources—characterized by depths of <3000 m, high temperature, and highly permeable rock formations—are generally commercially viable, depending on the regional energy market (see Figure 1). Such resources are usually found in volcanic regions, but the last 40 years have seen growing activity in research and development of the unconventional geothermal resources that exist outside the volcanic regions. To date, only one of these resources, Steam rises as a result of the excess heat of a standalone at Landau in Germany, has been shown to be commercially geothermal plant. GAPG would use geothermal heat more viable. However, given the significant promise of the uncon- efficiently. ventional geothermal resource, work to develop it continues.

46 VOLCANIC SEDIMENTARY ENHANCED GEOTHERMAL SYSTEMS

POWER POWER POWER

INSULATING INSULATING INSULATING SEDIMENTS SEDIMENTS SEDIMENTS

Underground Water Reservoir Underground Water Reservoir

SANDSTONES OR CARBONATES FRACTURES ENHANCED BY STIMULATION

HOT VOLCANICS HEAT FROM CENTER HEAT FROM CENTER OF EARTH OF EARTH

HYDROTHERMAL HOT ROCKS VOLCANIC FIGURE 1. Schematic of geothermal resources

The first step is to find geothermal resources with sufficient geothermal developments to allow stimulation trials/demon- temperature and at a depth that can be drilled economically. strations to support the development of this technology. Unconventional geothermal resources with the potential to be used for electricity generation are divided into two types:deep In the near term, the development of unconventional geo- natural reservoirs (DNRs) and enhanced geothermal systems thermal resources holds significant financial risks, which are (EGSs).1 DNRs are systems that make use of deep, naturally largely based on specific geological formations and the need occurring aquifers with high permeability. EGS resources have for stimulation. Such risks must be mitigated in some way; little natural permeability, hence these resources must have from this perspective, GAPG is a major opportunity. Figure 1 their permeability increased via stimulation or fracturing. shows a simplified means of extracting geothermal energy. Note that actual geothermal developments have many wells, The most significant unknown in unconventional geothermal as each producing well can only produce a limited amount of systems is the flowrate per well (or well pair). Unconventional flow. This means that the flow from any geothermal resource geothermal resources are chosen for their heat and their increases in a stepwise manner, with each new producing well potential permeability. The degree of permeability of a drilled. resource is directly linked to its flowrate. However, when there is insufficient natural flowrate, a reservoir’s permeability UNDERSTANDING GAPG THROUGH MODELING can be increased by fracturing. Stimulation technology in a geothermal context is immature, producing “good results some GAPG is based on the concept of using high-temperature of the time”.1 However, stimulation technology has provided geothermal fluid to heat the boiler feedwater of a thermal huge productivity improvements in oil and gas wells, so there power plant. It was first suggested by Khalifa et al. in 19782 as is hope that similar results will be possible in unconventional a replacement for low-pressure feedwater heaters (FWHs). In geothermal wells. Still, there must be sufficient unconventional 2002, Bruhn built on Khalifa’s design,3 making it significantly

www.cornerstonemag.net 47 TECHNOLOGY FRONTIERS

more flexible by allowing GAPG to partially replace any of the and/or ṁG4 (depending on the temperature and flowrate of low-pressure FWHs. After considering the low-temperature the geothermal fluid). geothermal resources most often available near thermal power plants, in 2010, Buchta focused on very low-temper- Given that geothermal fluids are not clean enough to mix with ature geothermal fluids (30–100°C) and considered applying feedwater, GAPG can only be used to replace closed feed- GAPG to only the first low-pressure FWH.4 water heaters (i.e., not the deaerator). In order to cool the extra steam coming through the turbine(s), additional con- Of course, geothermal energy is not the only renewable energy denser capacity is required, which could be managed by the source that can be applied to increasing the efficiency of thermal installation of a new, small condenser. power plants. Hu et al. investigated both geothermal and solar thermal sources for efficiency gains5 and found that the higher temperatures achievable from solar power makes it possible to RESULTS consider applying heat to the intermediate- and high-pressure FWHs. Then, more recently, Varney and Bean determined the In our modeling, we retrofitted GAPG to a 500-MW natural- net-power gain for all feasible geothermal flowrates and, fur- gas-fired, supercritical steam power station, specifically, the ther, discussed the flowrate and power limits of GAPG.6 Public Service Company of Oklahoma, Riverside Station Unit 1. Although we modeled a gas-fired plant, the analysis could Focused research over many years has generally found that have been applied to a coal-fired power plant and would yield GAPG can be retrofitted to any large thermal power station, the same results. although the economics are site-specific. It can be used to fully or partially replace the low-, intermediate-, or high-pres- One major advantage of GAPG is it’s flexibility: Power can be sure FWHs; however, it is most likely to be used to replace only generated from low geothermal fluid flowrates that otherwise the low-pressure FWHs. Depending on the needs of the indi- might be of little value in a stand-alone geothermal facility. vidual plant, GAPG can increase the power generated (power As these flowrates increase, power generation increases. For boosting mode) or it can be run to reduce the amount of fos- example, see Figure 3 which shows the incremental electricity sil fuel consumed (fuel saving mode). The simplest and most generated as the flowrate of the geothermal fluid is increased. flexible implementation was described by Bruhn and is shown Note that three different temperatures were evaluated (i.e., in Figure 2.3 In Bruhn’s implementation of GAPG, feedwater 150, 175, and 200°C). is withdrawn upstream of the first low-pressure FWH and is then heated by the geothermal fluid in the geothermal feed- Using geothermal heat to boost the efficiency of a thermal water heater (GFWH). The geothermally heated feedwater is power plant increases thermal efficiency above stand-alone geo- then returned to the feedwater stream via flows G1ṁ , ṁG2, ṁG3, thermal plants by 1.7 to 2.9 times, depending on the geothermal

Units: FWH - Feedwater heaters, GTh_C GFHW - Geothermal feedwater heater Steam take-oﬀs from States: F’s, G’s, b’s Flows: ṁ’s, ṅ’s Steam: Condensate: GFWH low pressure turbine GTh_H Geothermal Fluid:

ṁG1 ṁG2 ṁG3 ṁG4 ṅT

ṁG G2 ṁ2 G3 ṁ G4 ṁ G1 ṁ1 3 4

b1 b1_4

ṁ - ṁ - ṁ - ṁ ṁT- ṁ7- ṁ6- ṁ5 FWH1 FWH2 FWH3 FWH4 T 7 6 5

F1 F2 F3 F4 ṁ ṁ1+ ṁ2 + ṁ3 + ṁ4 ṁ2+ ṁ3 + ṁ4 ṁ3 + ṁ4 4 FIGURE 2. Schematic of GAPG

48 6 fluid temperature. However, there is a limit to the amount of 30 7 geothermal energy that can be utilized through GAPG at any 6 given thermal power plant—once the appropriate FWHs are 25 totally replaced by geothermal feedwater heaters, no further 5 20 additional power can be produced. To achieve this maximum 4 power limit, a geothermal resource temperature greater than 15 the outlet of the hottest appropriate FWH (in our modeling the 3 MaiximumExtra hottest low-pressure FWH was ~160°C) is needed (see Figure (MW) Power Net 10 2

4a). As the geothermal resource temperature increases above (%) Power Net Original

~160°C, the flowrate required to reach this maximum power limit 5 1 Power/ Net Extra Maximum 50 100 150 200 250 decreases (see Figure 4b). At temperatures less than ~160°C, the Geothermal Fluid Temperature (°C) maximum power limit cannot be achieved, irrespective of the flowrate (see Figure 4a). Our modeling showed that power could 290 be increased by a maximum of ~6.5% in the modeled 500-MW 270 supercritical plant. To achieve maximum power, a geothermal fluid flowrate of 190–290 kg/s was needed, with lower- flow 250 rates for the higher geothermal fluid temperatures and higher 230 flowrates for the lower geothermal fluid temperatures. Despite 210 this maximum power limit, considering the reduced risk to the geothermal developer and the power producer, it is still likely to (kg/s) Flowrate 190 be worthwhile to take advantage of GAPG. Geothermal Maximum 170 150 UNDERSTANDING THE IMPLICATIONS 50 100 150 200 250 Geothermal Fluid Temperature (°C) Coal-Fired Power Generators FIGURE 4. (a) Maximum power output from GAPG; (b) maximum flowrate GAPG allows coal-fired power plants to generate more power and reduce their carbon intensity through increased efficiency. Geothermal Developers Once a geothermal developer brings hot geothermal fluid to the surface, GAPG yields very little risk for the power plant Unquestionably, greater deployment of GAPG has major impli- owner. The revenue that can be generated by extra power cations for geothermal developers. GAPG allows them to focus production will be recognized by the plant operators, as will on what they do best, getting hot geothermal fluid from the the capital costs of installing the necessary geothermal feed- ground to the surface, and does not require the expertise or water heat exchangers, additional condenser capacity, and capital to produce and sell electricity. Further, the power plant is extra piping. Hence, power plant operators can decide what able to generate up to three times as much power per kilogram they are willing to pay for the hot geothermal fluid in order to of geothermal fluid as a stand-alone geothermal power plant.6 make sufficient profits—a site-specific consideration. Finally, if Importantly, GAPG allows the developer to sell whatever hot the geothermal fluid stops flowing, for any reason, the power fluid they are able to get to the surface. This means that they can plant can revert to its original operating conditions. take small steps—generate some revenue while learning more about the local geothermal resource and enhancing their capa- 30 bility. Later, the flowrate could be increased to further increase 25 the amount of heat provided to the thermal power plant. 20 15 COSTS 10 150°C 175°C Looking at the equipment required for a GAPG development, 5 200°C drilling costs clearly are the largest and most significant por- Extra Net Power (MW) Power Net Extra 0 tion of the overall capital cost. Of course, drilling costs vary 0 50 100 150 200 250 300 significantly with geology and local drilling market conditions. Geothermal Fluid Flowrate (kg/s) For example, it is estimated that, on average, a 1.5-km deep FIGURE 3. Geothermal fluid flowrate versus power generation well in the U.S. will cost $2.9 million and a 5-km well will cost

www.cornerstonemag.net 49 TECHNOLOGY FRONTIERS

$10.5 million. However, in Australia, which has a small num- with enormous potential. Geothermal energy is one of the ber of local drilling rigs and had to mobilize some rigs from few renewable energies capable of providing baseload power; the U.S., the expected cost for similar wells is $6.6 million and further, the size of the unconventional resource is potentially $15.3 million (all estimates are given in U.S. 2014 dollars).1 “truly vast”.1 For unconventional geothermal energy to progress it must take small steps and GAPG offers one such step. Further, it is difficult to estimate how many wells are required, because flowrate per well is the other significant unknown Additional opportunities may exist for the application of geo- in unconventional geothermal developments. The highest thermal energy at conventional power plants in the future. For flowrate from an unconventional geothermal well has been instance, low-temperature geothermal fluids are characterized observed at a site in Landau, Germany, which has a flowrate by temperatures in the range of the regeneration tempera- of 70 kg/s. However, the next highest flowrate per well was tures of post-combustion amine-based CO2 capture systems. recorded at Habanero 1 in Australia, which achieved a maxi- When commercial CCS comes online, GAPG could provide the mum flowrate of 40 kg/s. For these reasons, an average cost thermal load needed for CCS, thus allowing the power plant for a GAPG development cannot accurately be provided. efficiency loss from CCS to be dramatically reduced. Additionally, as mentioned earlier, stimulation technology, which can potentially increase flowrate, is currently far from GAPG allows unconventional geothermal developers to con- certain. Therefore, predicting the total costs to produce a centrate on the geothermal resource, not power conversion. given flowrate at a particular site is currently highly uncertain. Accordingly, power conversion can be carried out by expert However, with knowledge gained through further deployment thermal power plant operators, and up to three times as much of GAPG (or other forms of exploration in unconventional geo- power can be generated per kilogram of geothermal fluid as thermal resources) this uncertainty can be reduced. can be achieved in a stand-alone geothermal plant. GAPG offers power plant operators a way to increase power produc- Although accurate costings cannot be provided, it is fair to say tion and decrease their carbon footprint at essentially no risk. that, in general, unconventional geothermal developments GAPG is potentially a win-win option for both the geothermal (without the integration offered by GAPG) are not commer- developer and the power plant operator. cially viable yet. Based on drilling costs from the U.S., it is estimated that flowrates in the vicinity of 80–100 kg/s per REFERENCES well are required for commercial viability.1 However, it is clear 1. Australian Renewable Energy Agency. (2014). Looking forward: that GAPG provides up to three times more power than stand- Barriers, risks and rewards of the Australian Geothermal Sector alone unconventional geothermal developments. As much as to 2020 and 2030. Canberra: Commonwealth of Australia. geothermal energy development is driven by local markets, 2. Khalifa. H.E., DiPippo, R., & Kestin, J. (1978). Geothermal including renewable portfolio standards, it is important that preheating in fossil-fired steam power plants. Proceedings of th GAPG be recognized as a renewable energy even though it is the 13 Intersociety Energy Conversion Engineering Conference, San Diego, California. integrated with existing thermal power plants. 3. Bruhn, M. (2002). Hybrid geothermal–fossil electricity generation from low enthalpy geothermal resources: geothermal feedwater Although the economics of GAPG will be uncertain until the preheating in conventional power plants. Energy, 27, 329–346. technology is deployed, it is certain that GAPG is more eco- 4. Buchta J., & Wawszczak, A. (2010). Economical and ecological nomical than stand-alone geothermal plants. In addition, aspects of renewable energy generation in coal fired power plant supported with geothermal heat. Paper presented at the as greater experience and improved technology make lower Fourth IEEE Electrical Power and Energy Conference, 25–27 drilling costs and higher flowrates possible, unconventional August, Halifax, Nova Scotia, Canada. geothermal developments used for GAPG will become an ideal 5. Hu, E., Nathan, G.J., Battye, D., Perignon, G., & Nishimura, A. first step toward making unconventional geothermal energy (2010). An efficient method to generate power from low to medium temperature solar and geothermal resources. Paper commercially viable on a broad scale—to the future benefit of presented at Chemeca 2010: Engineering at the Edge, 26–29 both geothermal energy developers and the energy consumers September, Adelaide, South Australia. who currently rely on electricity from thermal power plants. 6. Varney, J., & Bean, N. (2013). Using geothermal energy to preheat feedwater in a traditional steam power plant. Proceedings of the 38th Workshop on Geothermal Reservoir Engineering, Stanford LOOKING FORWARD University, Stanford, California.

Unconventional geothermal energy is a relatively immature The authors can be reached at [email protected] technology, with high capital costs and large risks, but also and [email protected]

50 Shenhua’s Development of Digital Mines

By Han Jianguo supported by recent policies on safer coal production, energy Deputy General Manager, Shenhua Group Co., Ltd conservation, and emissions reduction. President, China Shenhua Energy Co., Ltd As the primary source of China’s energy and a raw material for many industries, coal is pivotal to the nation’s economic development. However, coal mining is a complicated opera- igital mines are based on the innovative application of tion, often carried out deep underground with many potential well-established, advanced information technologies to the areas of geological resource exploration, mine risks. These risks can be difficult to detect and even more so D to predict. Among other reasons, advanced mining systems, design and construction, safe and efficient production, operations, and decision-making. Digital mining allows for such as those incorporated into digital mines, are important because they can significantly reduce accidents.2 all aspects of mining to be evaluated simultaneously using digitized displays. The digital mine system can respond to, process, and utilize data to enable integration of different mining processes so as to achieve unified, centralized management “Digital mining incorporates modern of mining operations. Digital mining incorporates modern mining operations characterized by increased safety, reduced mining operations characterized environmental impact, intelligence, and high efficiency.1 In China, Shenhua Group (Shenhua) has led the development by increased safety, reduced and deployment of digital mines. The demonstration of China’s first digital mine successfully came online in the Jinjie environmental impact, intelligence, Coal Mine of Shenhua’s Shendong Coal Group, Co., Ltd on 27 December 2013, representing a major milestone for Shenhua and high efficiency.” and China.

THE IMPETUS FOR DIGITAL MINES IN CHINA Recently, mining technologies in China have been improved in significant ways: from the use of fully mechanized mining to the China’s government made it clear that the coal industry application of large, automated equipment, information tech- should increase efforts during the 12th Five-Year Plan period nologies, and artificial intelligence. Taking advantage of these (2011–2015) to develop and deploy an innovative coal system, modern technologies has propelled the development of China’s 3 founded on science and technology, that addresses the needs coal industry—and digital mines are a necessary next step. of coal-producing enterprises, is market oriented, and is based Today, China’s coal industry is facing the reality of a market on collaboration between industry, universities, and other characterized by slowing demand growth, decreased profits research institutions. This transformation in mining is further for many coal enterprises, and related problems such as overstaffing, low efficiency, poor safety records, and poor management. These issues are restricting the healthy and steady development of coal enterprises. Thus, digital mines and the associated technologies are needed now more than ever.

ARCHITECTURE AND THE MAJOR COMPONENTS OF A DIGITAL MINE

Shenhua’s digital mine was developed taking into consideration the actual needs of coal producers (both underground and The ability to monitor operations from a central location is a open-pit) in China. Three key challenges had to be addressed: key component of the digital mine at Jinjie. mining information acquisition, transmission, and processing.

www.cornerstonemag.net 51 TECHNOLOGY FRONTIERS

Digital Mine Architecture

Shenhua’s digital mine consists of a five-level structure of L5 information standards (i.e., equipment, controls, production Decision support level execution, operation management, and decision support), • Operaons which fully incorporate information-based corporate decision- performance management • Enterprise support making as well as information-based production management on decision-making and automated production processes. The complete architec- L4 Operaon management level ture of the digital mine is shown in Figure 1. • Enterprise resource planning (ERP) • Strategic resource management (SRM) • Strategic resource management system The architecture of Shenhua digital mines includes the com- • Coal producon and producon control • Synergized dispatching system of producon, ponents listed in Table 1. transportaon, and sale L3 Producon execuon level • Centralized intelligent and integrated producon management system Centralized Platform Design L2 Controls level • Centralized producon monitoring and control system L1 Equipment level Two platforms have been developed for Shenhua’s digital • Smart controllers • Smart instruments • Base staons • Smart cameras mines—the centralized production-monitoring platform and FIGURE 1. The integrated application architecture of digital the production execution platform. Within these platforms are mines 68 subsystems. Data can be freely transferred among these platforms and subsystems. and management for data exchanges between production management and control. The centralized production-monitoring platform is primarily used to integrate data and to control the onsite surveillance The interacting network for underground coal mines is system and monitoring system; the production execution plat- shown in Figure 2. As shown in the figure, information can form mainly provides support to the subsystems of production be exchanged and shared through a network. An interface

TABLE 1. Major components in Shenhua’s digital mine

Digital Mine Area Components Included Infrastructure Data center, network, admin communication system, dispatching display, and a video-conference system Monitoring system: Fully mechanized coal mining face, heading face, hoisting system, main transport, subsidiary transport, power distribution, water supply and sewage, ventilation, coal washery, truck Centralized loading, gas extraction, nitrogen injection, grouting, fire control sprinkling, refrigeration and cooling, air Production compression, boilers, and outsourcing coal monitoring Monitoring Surveillance system: Safety surveillance and monitoring, personnel and vehicle tracking and positioning, System industrial television, communication dispatch, early warning of gas and coal outburst, beam tubes, dust, hydrogeology, roof pressure, microseism of ground pressure, wastewater treatment, waste rock discharge in production, gas inspector patrolling, and an unattended intelligent lamp room system Production execution platform, with a 3D exhibition subsystem, production management subsystem, Production dispatch management subsystem, electromechanical management subsystem, “one ventilation and Execution three prevention” management, safety management subsystem, coal quality management subsystem, System design management subsystem, energy conservation and environmental protection management subsystem, central data analysis subsystem, etc. Management of planning and overall budget, enterprise resource planning (ERP), supplier relation, Operation customer relation, strategic resource (SRM), costing, system, intrinsic safety, office automation, auditing, Management science and technology, energy conservation and emission reduction, archives, references, statistics, System administration and logistics, coal production supervision, etc. Decision Operation performance management and enterprise decision support Support System

Operaon n

Operaon and management decision-making and decision

ERP system … … aon system ty fe sources Coal producon supervisio and management Equipment Equipment management Project management Sa management Oﬃce automao Oper performance management Enterprise decision support Human re

Enterprise service bus (ESB) n l

ta ta n

Business on and e va l da

subsystem re ch nmen omechanical hibion

Producon ra Producon ty fe execuon execuon system eveno Dispat management Electr management One venlao and th pr Sa management Design management ro envi protecon Energy conser analysis Coal quality management Cent 3D ex Producon Producon management

*Plaorm and applicaon adapter, data adapter

Producon execuon plaorm

*Data adapter

Centralized producon monitoring plaorm em Hardware interfaces: Upper computer, Controls syst *Subsystem interfaces So ware interfaces: OPC, drives, DDE/NETDDE, PLC, subnetwork, extensions independent development ed producon ed producon liz n ra ce fa monitoring Cent Detecon system Monitoring system ching ng ……ty fe uck loading ce Hois Tr Hydrogeology Fully mechanized coal mining fa Heading Sa surveillance and monitoring Dispat communicao

Hardware interfaces: Hardwired or ﬁeldbus *Interfaces So ware interfaces: Drives (CAN, FF, Proﬁbus, Modbus, etc.)

Equipment Sensors Instruments Base staon Cameras Etc. FIGURE 2. The interacting network for digital mines: underground coal mines meeting international standards is provided at the network the coal mine and operation management through a single and serial port levels, so that all subsystems can be connected display was achieved. and various software and hardware can be integrated, making the systems connected and interconnected. Aided by this coal mine monitoring software platform, the demonstration digital mine operators were able to transition Architecture of the IT Infrastructure from a conventional top-down management model to more efficient, data-based control of mining, excavating, machining, The architecture of the IT infrastructure of Shenhua’s digi- transporting, and circulating. The use of this software platform changed the dispatch room into a 24-hour command post, tal mines can be divided into three layers, from the lowest accomplishing full data sharing, intelligent linkage, and auto- upward: network, mine machine room, and the application matic control for mining, excavating, mechanical operating, terminals (see Figure 3). transportation, and circulating systems by enabling control room operators to have full access to data throughout the MAJOR INNOVATIONS FROM SHENHUA’S mine as well as control of automated equipment and commu- DEMONSTRATION OF THE DIGITAL MINE nication with the personnel outside the control room.4

The Jinjie demonstration of Shenhua’s digital mine had several Another important accomplishment during the Jinjie demon- successful aspects. For instance, a software platform for coal stration related to the GIS-based automated mining model, mine monitoring was developed after analysis and assessment which allows the memory-based shear cutting of the coal- in the Jinjie demonstration mine. Through use of this system, face to be controlled remotely from the surface. Models and comprehensive monitoring and multifunctional operation of parameters for the slicing and control of the coal cutter were

www.cornerstonemag.net 53 TECHNOLOGY FRONTIERS

IMPACTS AND ACHIEVEMENTS Applicaon Dispatching Administrave Video-conference Etc. terminals display system communicaon system The Jinjie demonstration of Shenhua’s digital mine provided a large amount of information covering all underground System so ware Operang system System so ware Safety facilies systems, environments, and equipment. This cache of infor- Machine Data center Servers Virtualizaon mation helped achieve the complete, accurate, real-time, room Servers ViGap for the of the and automatic collection of data. Based on this, the overall mines mining Backups Storage area digital mines program established a big data-based production Backups Storage Resource supply management command system, which revolutionized how commands and controls are executed. For example, equipment is controlled Network Automaon Informaon Wireless by a remote computer rather than by a person. Additionally, plaorm network network network controls are now centralized rather than decentralized as was ViGap ViGap the case in the past. FIGURE 3. IT infrastructure architecture of the Jinjie coal mine The construction and application of Shenhua’s digital mines based on the geological drilling and the actual data (e.g., min- program has been applied at the following sites (in addition ing height and fluctuation) of the working face. This system to Jinjie): Da Liuta, Yu Jiaoliang, Shi Yitai, Shangwan, Bu Lianta, allowed for coal to be cut automatically and the slicing path Baode, Wulan Mulun, Ha Lagou, Cun Caota, Liuta, Jinfengcun to be recorded. The system was able to receive input through Caota, No. 1 mine at Wanli, and Bu Ertai. These 14 applications either the sensors or human intervention. No matter the are reporting substantial, positive impacts to operations, the source, the system recorded any interventions and incorpo- most important of which are described below. rated that information into subsequent slicing parameters (i.e., a self-correcting model). This process repeated itself Increased efficiency and downsized payrolls: The shift from automatically, and this technology has been applied to five direct onsite control to indirect remote control can reduce other fully automated mining faces in Shenhua Shendong Co. the operation personnel underground. For example, a change on a trial basis. to centralized control can reduce the underground workforce by 52 production workers. This represents a cost savings of One notable achievement of the Jinjie demonstration mine RMB9.2 million (US$1.49 million) and 190,700 labor hours. related to the transportation of coal on a conveyor whose speed was regulated using laser-based measurements in an Refined production management and reduced equipment intelligent closed loop. The laser-based detection device mon- downtime:Data sharing within the information systems makes itors the amount of coal on the belt: When an increase in the it possible for the equipment and system to operate only as quantity of coal was detected, the conveyor sped up imme- needed. Therefore, minimizing the ineffective operation time diately. This system led to energy savings and more efficient of the equipment and maximizing production efficiency can production. be achieved. Take the main transport belts, for example. It is estimated that the variable speed control technologies can The Jinjie demonstration mine used a 10-GB Ethernet (10- increase the utilization of the underground electromechani- giga) underground high-speed transmission network, allowing cal equipment by 2%. This translates into a reduced power the integration of a few sub-networks and allowing real-time consumption of 25% and a cost savings of about RMB500,000 transmission of mass data from multiple sources. In addition, (US$80,883) on each belt per year. a wireless portable hand-held terminal was successfully developed and used to monitor the real-time situations at mobile Improved productivity, enhanced recovery of resources, and locations. This underground network was able to satisfy the increased utilization of equipment: With the implementa- need to access and transmit 57,000 measured sources of data tion of the digital mines program, energy usage is reduced. as compared with the conventional 15,000 measured data Equipment abrasion is also reduced. The output of each coal- points. The transmission network is shown in Figure 4. face is increased by about 10% and excavation of this mining face is extended by more than 12%. The efficiency of the By using wireless internet technologies such as 3G, Wi-Fi, workforce can be increased by about 16% and the utilization and radio frequency underground, users achieved automated of the equipment by about 5%. In the last three years, coal data collection in real time using mobile terminals suchas output increased by 15.09 million tonnes and sales increased cellphones, tablets, and point inspectors, leading to under- by RMB7.873 billion (US$1.285 billion) in the Jinjie, Da Liuta, ground paperless records to ensure timely and accurate data and Yu Jiaoliang mines alone after they implemented the digi- collection. tal mines approach.

54 Shendong’s C & C08 Switch Telecommunicaon network 3G clock server

Base staon controller 3G core network of Shendong site

10-giga surface switch 10-giga surface switch

10-giga underground switch 10-giga underground switcchh Central substaon CentC ral substaon Central substaon

Substaon tree and ring networking

Central substaon Central substaon

10GE backbone circuited network Substaon chain-shaped networking FEF opcal port 10-giga underground switch 10-giga underground switchh Central Central substaon Central substaon substaon FE electrical ports / FE opcal port SMA FE opcal port FE opcal port Base staon antenna

Industrial control PLC Locator card Broadcast terminal Broadcast terminal Explosion-proof camera Cellphones Industrial control PLC FIGURE 4. Transmission network architecture of the mine at Jinjie

Enhanced safety: With the safety management system, acci- program is strategically significant for the industry. It will fur- dent prevention and control has replaced reactive approaches ther improve production efficiency, reduce costs, and enhance to safety. The artificial intelligence-based early warning sys- core competiveness for mining. It serves as a cornerstone to tem has significantly improved the safety-related data and the construction of a modern, safe production management considerably improved the safety of mining operations. system for the coal industry, leading to a modernized coal industry with a highly technical foundation, profitable opera- A newly formed GIS-based true three-dimensional emergency tions, low energy consumption, reduced pollution, increased rescue system linking the underground with the surface has been safety, and efficient utilization of personnel. created: Potential problems in operation can be remotely moni- tored and diagnosed. Experts can propose effective solutions and REFERENCES provide technical support directly online through consultation. 1. Han, J.G., Yang, H.H., Wang, J.S., & Pan, T. (2012). Research of construction of digital mine of Shenhua Group. Industry and CONCLUSIONS Mine Automation, 2012, 38(3), 11–14. (In Chinese) 2. Lu, X.M., & Yin, H. (2010). Definition, connotations and progress of digital mine. Coal Science and Technology, 38(1), 48–52. (In The rapid development and mutual integration of IT and Chinese) automation technology have rejuvenated organizational man- 3. Wu, L.X. (2000). The digital earth, digital China and digital mine. agement, production and decision-making, and technology Mine Surveying, 1, 6–9. (In Chinese) 4. Wang, J.S., & Pan, T. (2014). Practical exploration on construction and production scales of China’s coal industry. The construc- of digital mine. Industry and Mine Automation, 40(3), 32–35. (In tion and successful operation of Shenhua’s digital mines Chinese)

www.cornerstonemag.net 55 TECHNOLOGY FRONTIERS

Direct Carbon Fuel Cells: An Ultra-Low Emission Technology for Power Generation

By Christopher Munnings low-emission power generation. However, further improve- Senior Research Scientist, CSIRO Energy Flagship ments to conversion efficiency and emission reductions remain highly desirable. Direct carbon fuel cells (DCFCs) are an emerg- Sarbjit Giddey ing technology that has the potential to almost double electric Senior Research Scientist, CSIRO Energy Flagship efficiency (i.e., to 65–70%) and halve greenhouse emissions compared with conventional coal-based power plants. Rather Sukhvinder Badwal than burning coal, these fuel cells electrochemically oxidize it; thus their efficiency is not Carnot cycle limited. (See Figure 1 CSIRO Fellow, CSIRO Energy Flagship for a comparison of the efficiency of different coal-to-electricity options.) Furthermore, DCFCs produce two separate exhaust streams, one that is essentially oxygen-depleted air

nergy, particularly electrical power, is one of the most and the second being a concentrated stream of CO2. Thus the

critical components of any modern industrial economy energy penalty for CO2 capture is significantly lower (almost with most economies being based on low-cost abundant zero) compared to post-combustion capture. DCFCs are at E an early stage of development, but a number of groups have energy supplies. In this regard, coal continues to be the primary energy source of choice for electrical power generation. recently become involved in the development of this tech- Coal can be stored easily and converted into electrical power nology leading to a range of novel systems and concepts being on demand regardless of season or local weather conditions. investigated. In this article we provide a broad overview of the However, conventional coal-fired power generation can result technology. More comprehensive technical information on various systems can be accessed in References 1–3. in high emissions of CO2 and other pollutants. These can be captured or neutralized; however, in some cases this can greatly increase cost. “Direct carbon fuel cells are an New coal-based power generation technologies currently being demonstrated and deployed, such as oxy-combustion, emerging technology that has the supercritical or ultra-supercritical coal-fired power plants, various gasification technologies, and direct injection coal engines, potential to almost double electric can lead to incremental or dramatic reductions in emissions. Such technologies are critical as the world progresses to efficiency and halve greenhouse

70 emissions…” 60 50

ﬃ ciency (%) 40 WHY FUEL CELLS ARE MORE EFFICIENT THAN COMBUSTION 30 20 Fuel cells convert fuels to electricity via electrochemical oxi- 10 dation of fuel, rather than via combustion, to generate heat 0 and pressure that is then converted into electricity through a

Net Power Plant E Brown Black SC ST USC ST IGCC DICE DCFC Coal ST Coal ST heat engine, such as a steam or gas turbine. In conventional fuel cells, gaseous (CO, H2, CH4) or liquid (methanol, ethanol) FIGURE 1. Average efficiency of coal-based power generation fuels are converted into electrical power. DCFCs operate via technologies the same broad principle; however, the solid high-carbon fuel Notes: Brown Coal ST = brown coal steam turbine; Black Coal ST = black coal (such as coal) is consumed to produce electrical power through steam turbine; SC ST = supercritical steam turbine; USC ST = ultra-supercritical steam turbine; IGCC = integrated gasification and combined cycle (gas reactions (1) and (2), respectively occurring at the cathode turbine); DICE = direct injection coal engine; DCFC = direct carbon fuel cell and anode electrodes of the cell. The two electrodes are kept

56 separated by an oxygen ion-conducting ceramic membrane coal to electricity of around 65–70% are considered attain- (four types of direct carbon fuel cells are shown in Figure 2). able with the remainder of the energy being lost as waste heat.1 If the waste heat can be utilized (for instance, for coal - 2- Cathode: O2 + 4e → 2O (1) drying or pyrolysis) then overall efficiencies in the region of 80–90% could be achieved. This is higher than attainable with 2- - Anode: C + 2O → CO2 + 4e (2) a gaseous fuel; for comparison, leading MW-scale molten carbonate (FuelCell Energy) and solid oxide fuel cells (SOFC) The fuel is housed on the anode side of the membrane with (Bloom Energy), operating on natural gas, have an electrical air being used as the oxidant on the cathode side. The oxygen efficiency of around 47% and 52%, respectively. molecules become ionized [reaction (1)], and the oxygen ions flow across the membrane and react with the fuel to produce

CO2 [reaction (2)]. The electrons released via this process move through an external load generating an electrical cur- “Solid fuels ... can be easily rent. Fuel cells operate similarly to a battery; however, unlike a battery, the fuel cell is continuously “charged” as the fuel is separated from the gaseous replaced at the anode as it is consumed. products ... leading to nearly Electrochemical oxidation of fuels to produce electricity is highly efficient because fuel cells contain few moving parts 100% fuel utilization...” and do not rely on pressure or temperature gradients to operate (again, not Carnot cycle limited). The efficiency of a fuel cell system is defined by four factors: system losses, fuel FUEL CELL DESIGNS: KEY CHALLENGES utilization, electrochemical losses, and the thermodynamic AND TECHNICAL MERITS (theoretical) efficiency of the system. The system losses are typically a minor component (approximately 10%) and are DCFC technology is at an early stage of development, with largely similar for most high-temperature fuel cells. Solid many organizations focusing on the fundamental aspects of fuels (such as coal) can be easily separated from the gaseous the technology.1,3 In general, the key challenge is to strike a products (i.e., CO2 in the exhaust) leading to nearly 100% fuel balance between cost, performance, and lifetime. utilization compared to 80–95% for conventional gaseous fuel cells. Electrochemical losses are caused by slow reaction kinet- At the core of each proposed fuel cell system is the cell design, ics at the electrode/electrolyte interface and transport of ions which determines all other features. The four most commonly through electrodes and the electrolyte. These losses are sig- suggested fuel cell designs that can use solid fuels are shown nificantly reduced by operating at high temperature but are in Figure 2 and compared in Table 1. still greater for carbon than for conventional gaseous fuels. The thermodynamic efficiency of a DCFC is largely indepen- The main difference between each of these systems, and com- dent of temperature, and theoretically 100% of the chemical pared with other conventional fuel cells, is the fuel electrode energy in the fuel is available for conversion to electricity. (anode) and the fuel delivery system. Modifying the fuel elec- Taking the typical losses into account, practical efficiencies for trode allows a greater area for the reactions to occur between

Molten metal Gasiﬁcation Molten salt Solid state reaction - e e- e- e-

CO2 MO CO2 CO2 CO2 2- 2- O 2 2- O CO CO3 2- C O 2- O2 (air) O O2 (air) O2 (air) M O2 C or CO CO C or CO C or CO

Reaction zone Anode Electrolyte Cathode

FIGURE 2. Pictorial representation of different DCFC designs under consideration globally

www.cornerstonemag.net 57 TECHNOLOGY FRONTIERS

TABLE 1. Comparison of four common direct carbon fuel cell designs

Molten carbonate/hybrid Descriptor Molten metal Gasification Solid state with solid oxide*

“Metal shuffle” In the molten carbonate The fuel can be gasified The anode is a mixed mechanism: system, the molten within the anode chamber ionic electronic electrolyte is held or gasified externally, conducting (MIEC) Metal is oxidized at between porous then cleaned and fed material. the surface of the electrodes. to a conventional high- solid electrolyte. The MIEC material temperature solid oxide or In the hybrid system, supplies oxide ions and The metal oxide mixes molten carbonate fuel cell. the electrolyte is a solid removes electrons, with molten metal oxide with the molten External gasification leads allowing the entire anode Design then contacts the carbonate only in the fuel to lower efficiency. Internal surface to be used for principles fuel. chamber. gasification requires novel fuel oxidation reactions. The fuel reduces the anode materials not used In both cases, fuel mixes oxide back to metal. in conventional fuel cells. with molten carbonate which supplies oxygen Both systems can use to the reaction sites via porous electrodes. movement of carbonate ions. Potentially simple fuel Fuel is fed continuously Conventional solid oxide or Can consume both solid feed system to the electrode/ molten carbonate fuel cell and gaseous fuels electrolyte interface. can be used. Fast fuel oxidation Solid anode material reaction Could use a wide range of Waste heat can be used avoids corrosion and solid fuels to produce gasification containment issues of Could use a wide products (CO and H ) to molten systems. Advantages range of fuels Has the highest electrical 2 increase system efficiency. efficiency of any Less complex than High tolerance to technology gasification systems sulfur impurities and allows kW-scale deployment before scale-up Very low tolerance Short cell life Large, expensive plant Difficult to deliver solid to ash needed to integrate all fuel to reaction sites Difficult to stop the components (e.g., gasifier, Tested mainly with reaction between the Slow reaction kinetics for hot gas cleanup, high- high-purity non-solid molten carbonate and fuel oxidation reaction temperature fuel cell, gas fuels, e.g., heavy oils, other cell materials turbine, etc.). Disadvan- natural gas Molten carbonate can tages Comparably low Low cell operating speed up the formation efficiencies if waste heat voltages reduce of carbon monoxide from fuel cells is not used efficiency (CO), which is lost to the for gasification. exhaust, reducing overall efficiency

Potential electric ~30%1 up to 80%1 35–58%1,3 65–70%1 efficiency

*Various other molten salts and mixtures of molten salts have been trialed, including sodium and potassium hydroxides with consumable carbon anodes.1

58 The direct contact solid state designs fall in-between the external gasification fuel cell systems and systems with molten components and are more resilient to impurities than conventional SOFCs or fuel cells containing molten components. This is because the MIEC anodes are typically a solid ceramic material, which is far more resistant to chemical attack or poisoning and thus will tolerate a greater level of impurities and ash than molten systems. High levels of ash will still be detrimental to the performance of the fuel cell and will be more difficult to remove from a fuel cell system than a gasifier. Thus ash content of the fuel may need to be reduced by fuel pre-processing prior to its use in a direct-contact solid-state fuel cell. Although high ash contents are generally considered detrimental, not all ash constituents have a negative impact on cell performance: Some impurities contribute The 59-MW fuel cell park, South Korea, is indicative of the to improvement in cell performance. This was well demonstrated scale of a direct carbon fuel cell facility (photo courtesy of by Rady et al., who showed that the presence of brown coal ash FuelCell Energy). led to a 25% increase in power output of the fuel cell. the solid fuel and the electrode/electrolyte interface. Having a larger reaction area means that more electrons can be pro- FUEL CELL POWER PLANTS duced, and therefore more electrical power can be generated. Conventional fuel cells have porous electrodes, which allow One key advantage of high-temperature fuel cells is the greater gas to penetrate and react over a large area. As this is not pos- availability of the waste heat from the system. This, combined sible with a solid fuel, alternative fuel electrode designs are with the low-pressure operation and the modular nature of needed to increase the area available for reaction. fuel cells, allows far greater flexibility in design of fuel cell plants and leads to greater integration possibilities. Figure 3 provides a schematic overview of an envisaged DCFC power FUEL REQUIREMENTS generation module operated on coal. Depending on the technology chosen, 10–30% of the fuels’ energy may be available as The fuel requirements are yet to be fully determined, with only high-grade heat (600–800oC) that could be used for fuel drying limited studies investigating the effect of impurities and fuel or pyrolysis, used within a low-pressure steam turbine, or used composition on the overall fuel cell performance. There are no for the production of syngas. In this way the DCFC can be seen defined specifications for an ideal fuel; however, fuel proper- both as a coal-based power production technology and as a ties which could potentially improve the performance of the key enabler for the production of high-value-added products fuel cell include high electrical conductivity, low crystallinity, for export from abundant low-grade fuels, such as Victorian small particle size, friable particles, high surface area, and low brown coal. Furthermore, since the waste stream from a DCFC ash. DCFCs are less sensitive to other fuel properties that are 2 is pure CO2, this whole process could conceivably have a very critical for combustion, such as moisture and thermal content. small carbon footprint if CCS is employed. Further reductions in CO emission could be realized if waste biomass sources are In terms of reactivity with fuel impurities, systems with 2 mixed with conventional fossil fuel carbon sources. molten components generally will have significantly more stringent fuel requirements as even small levels (less than 1%) of ash will accumulate within the anode chamber and react CURRENT STATUS AND FUTURE with the molten metal or carbonate components, leading to PROSPECTS FOR COAL-FUELED DCFCS solidification of some components and rapid degradation in cell performance. In general, grid-connected fuel cells are becoming a reality— with a number of commercial systems now available in several If gasification is to be used in conjunction with conventional markets ranging in size from a few hundred watts to larger fuel cells, then ash can be removed during gasification; how- scale units in the MW range. All of these systems operate on ever, gas cleanup to remove particulates, sulfur, mercury, and gaseous fuels. These fuel cell systems offer some benefits in phosphorous-based impurities would still be required. If these terms of emissions, efficiency, and flexibility of scale, but are impurities can be reduced or eliminated via coal cleaning or essentially an incremental step when compared to advanced careful selection of fuel, then it is likely to significantly reduce combined-cycle gas turbines. DCFCs are, by comparison, the overall capital cost of the final gasification DCFC installation. in their infancy, but offer a step increase in efficiency over

www.cornerstonemag.net 59 TECHNOLOGY FRONTIERS

Thermal output

Oxygen Coal pre- depleted air treatment & Air pulverization

Pure CO2 for Material ﬂow sequestration

Gas ﬂow recycle 2

Thermal ﬂow CO

o 800 C Fuel cell stack

Ash & other by-products

FIGURE 3. A schematic of an envisaged DCFC power generation module operated on coal traditional and emerging solid fuel combustion technologies REFERENCES with the added advantages of low greenhouse gas emissions and the low cost and energy requirements for CCS. This implies 1. Giddey, S., Badwal, S.P.S., Kulkarni, A., & Munnings, C. (2012). the fate of DCFCs is largely dependent on developments in the A comprehensive review of direct carbon fuel cell technology. global energy market. If there is a drive to maintain and grow Progress in Energy and Combustion Science, 38, 360–399. 2. Rady, A.C., Giddey, S., Badwal, S.P.S., Ladewig, B.P., & power production from solid fuels, particularly low-grade solid Bhattacharya, S. (2012). Review of fuels for direct carbon fuel fuels, DCFC is likely to become a very attractive future tech- cells. Energy & Fuels, 26, 1471–1488. nology that could offer a 10–50% increase in efficiency over 3. Gur, T.M. (2013). Critical review of carbon conversion in “carbon conventional power generation technologies, that is compat- fuel cells”. Chemical Reviews, 113, 6179–6206. ible with carbon capture and storage, and that is adaptable in 4. Giddey, S., Badwal, S.P.S., Kulkarni, A., & Munnings, C. (2014). terms of scale of deployment. Performance evaluation of a tubular direct carbon fuel cell operating in a packed bed of carbon. Energy, 68, 538–547. 5. Rady, A.C., Giddey, S., Badwal, S.P.S., Ladewig, B.P., & ACKNOWLEDGMENTS Bhattacharya, S. (2014). Direct carbon fuel cell operation on brown coal. Applied Energy, 120, 56–64. The authors acknowledge the support of Brown Coal Innovation Australia (BCIA) for this work and Dr. Aniruddha Kulkarni for the The lead author can be reached at Christopher.Munnings@ internal review of this document prior to publication. csiro.au

60 Exploring the Status of Oxy-fuel Technology Globally and in China

By Zheng Chuguang institutions and companies advancing oxy-fuel technolo- Professor, State Key Laboratory of Coal Combustion, gies include the following: Energy & Environmental Research Huazhong University of Science and Technology Center, Argonne National Labs (ANL), Babcock & Wilcox Director, Advanced Coal Technology Consortium, (B&W), Air Products, and Jupiter Oxygen in the U.S.; IHI and Clean Energy Research Center Hitachi in Japan; Canmet in Canada; International Flame Research Foundation in the Netherlands; BHP Billiton, Newcastle University, and CS Energy in Australia; CIUDEN xy-fuel technology is characterized by the use of pure in Spain; Alstom in France; Doosan Babcock in the UK; and oxygen or oxygen-enriched gas mixtures to replace air Vattenfall in Germany. Extensive research, development, and during combustion of (most often) fossil fuels. After demonstrations are also occurring in China (shown in red in O Figure 1), which are discussed in detail in later sections. the fuel is burned, flue gas with a high concentration of 2CO

is generated, which facilitates the capture of CO2. First proposed by Abraham in 1982, the purpose of the technology 1 was to produce CO2 for enhanced oil recovery (CO2-EOR). As “Following 30 years of development, concerns related to climate change have intensified, the need to control CO2 emissions (as the principal greenhouse gas) oxy-fuel technology has matured has also gradually increased in prominence. As a technology option with great potential for reducing 2CO emissions, oxy- and possesses the fundamental fuel combustion has become a focus of research worldwide.2 characteristics necessary for THE STATUS OF INTERNATIONAL OXY- FUEL TECHNOLOGY DEVELOPMENT commercial application.”

Figure 1 shows the development status and capacity of oxy- fuel projects at various research institutions; projects range in Pilot-Scale Demonstrations scope from laboratory scale to commercial applications. Some projects began as early as the 1980s. The principal research Since 2005, oxy-fuel pilot projects have significantly advanced the overall technology. Table 1 lists the pilot projects at the 1000 tens of MWe scale that are under construction or have been Lab- and pilot-scale (≤1 MWe) Whiterose 426 completed. These include the world’s first 10-MWe oxy-fuel ENEL 320 Pilot- and demonstration-scale (without CCS) Endosa 300 comprehensive process test installation, built by Sweden’s Shenmu 200 Demonstration-scale (with CCS) FutureGen 168 Vattenfall in 2008 in Schwarze Pumpe, Germany. The world’s 100 Youngdong 100

) first 30-MW oxy-fuel pilot power plant, which also boasted

e e Renfrew 30 Callide A 30 the world’s largest capacity, was completed by Australia’s CS Pearl Plant 22 International Comb 11.7 Vattenfall 10 Oxy-coal 13.3 Energy in 2011 in Callide. The 7-MW oxy-fuel pulverized coal B&W 10 HUST 12 e 10 CIUDEN 10 Jupiter 6.7 boiler and world’s first 10-MWe oxygen-enriched fluidized bed TOTAL CIUDEN 6.7 JSIM/NEDO(Oil) 4.0 OHIO 10 (NG) 10 pilot were completed at CIUDEN’s Technology Development

Capacity (MW Center in 2012 in Spain. In China, the first 12-MWe oxy-fuel ANL/EERC 1.0 IFRF 1.0 ENEL 1.0 1 HUST 1 Alstom 1.0 power installation will be completed by the end of 2014. IHI 0.4 B&W/AL 0.4 PowerGen 0.3 ANL/BHP 0.2 IVD-Stuttgart 0.2 RWE-NPOWER 0.2 CANMET 0.1 HUST 0.1 Large-Scale Demonstrations 0.1 1980 1990 2000 2010 2020 Table 2 lists the large-scale oxy-fuel pilot projects being con- Year placed into operation ducted globally. In 2003, the U.S. government announced FIGURE 1. Status of international oxy-fuel project research.3 plans to construct a zero-emission plant based on coal gasifica- (Projects conducted in China are shown in red.) tion; the project was named FutureGen. After more than seven

www.cornerstonemag.net 61 TECHNOLOGY FRONTIERS

TABLE 1. Completed and planned oxy-fuel pilot projects

New or Construction Main Electricity CO CO Flue Gas Name (Location) MW 2 CCUS 2 e Retrofit Began Fuel Generated Capture Purity Purification Vattenfall (Germany) 10 New 2008 Coal No Yes Yes 99.9% SCR, ESP

Callide (Australia) 30 Retrofit 2010 Coal Yes Yes No FF

Total (France) 10 Retrofit 2009 NG Yes Yes Yes 99.9% FGD

CIUDEN (Spain) 10 New 2010 Coal Yes Yes No SCR, FF

CIUDEN (Spain) 7 New 2010 Coal Yes Yes No SCR, FF

Jamestown/Praxair (U.S.) 50 New 2013 Coal No No

Jupiter Pearl Power Station (U.S.) 22 Retrofit 2009 Coal No No

Babcock & Wilcox (U.S.) 10 Retrofit 2008 Coal No No 70%* SCR, FF

Doosan Babcock (UK) 13 New 2008 Coal No No

HUST (China) 12 New 2011 Coal No Phase 2 Phase 2 80%

Notes: SCR = selective catalytic reducer; ESP = electrostatic precipitator; FF = fabric filter; FGD = flue gas desulfurization; NG = natural gas *Post-drying years, the direction of this project changed. In August 2010, the South Korea is also actively making progress on an oxygen- U.S. Department of Energy launched FutureGen 2.0, which was enriched coal-fired power station demonstration project—the based on carbon capture from oxy-fuel coal combustion. US$1 country plans to build a 100-MWe pilot power station by 2015. billion (the total budget for the project is now $1.3 billion) was allocated for the construction of a 200-MWe (now adjusted to In China, several large-scale oxy-fuel projects are currently

168-MWe) commercial-scale oxy-fuel power station. The objec- conducting pre-feasibility or feasibility studies, including the tive is to obtain 90% carbon capture and remove most of the Shenhua Group’s 200-MWe Shenmu power plant, Sunlight pollutants, including SOx, NOx, Hg, and particulate matter. Coking’s 350-MWe thermoelectric pilot, China Datang

Corporation’s 350-MWe Daqing power plant, and Xinjiang

The UK power company Drax also announced its White Rose Guanghui Energy’s 170-MWe pilot. commercial-scale 426-MWe oxy-fuel carbon capture demonstration project. The Yorkshire-based project obtained Among the aforementioned industrial-scale installations, official support from the UK’s Department of Energy & Climate a number of key components necessary for the oxy-fuel Change in December 2013. A front-end engineering design process have been verified. For instance, major power equip- (FEED) study is currently being conducted. ment manufacturers such as Alstom, IHI, Doosan Babcock,

Table 2. Large-scale oxy-fuel projects

Project Owner/ Technology Progress and Planned Country Scale and Parameters Power Plant Source Construction Start Time Drax Power 426 MW Alstom, UK e Entering Phase 2, feasibility study White Rose Ultra-supercritical Air Products FutureGen 2.0 168 MW B&W, NETL, Foster Wheeler, Entering Phase 2, U.S. e Ameren and FGA Subcritical Air Liquide feasibility study underway South Pre-feasibility study completed; Young Dong 100 MW Doosan Babcock Korea e applying for permit

62 Hitachi, and B&W have completed evaluation tests on single Program for carbon emissions reduction, and launched a com-

10-MWe oxy-fuel swirl burners that can be used in large-scale prehensive national system for the research, development, and demonstrations. Alstom has completed verification tests on demonstration of oxy-fuel-based CO2 capture. Table 3 lists the a 15-MWth oxy-fuel tangential combustion system. Foster major fundamental oxy-fuel combustion research projects sup- Wheeler has completed semi-industrial verification of a ported by the Chinese government and industry.5

10-MWe oxy-fuel CFB. Gas separation equipment suppliers Air Products, Linde, and Air Liquide have completed evaluation HUST has already carried out much research and development tests of compression/purification systems at the 10–30-MWth work on basic oxy-fuel combustion, technology development, level. The success of these tests has laid the foundation for and pilot projects, which has largely driven oxy-fuel combus- further large-scale projects. tion technology development in China. Based on progress to date, HUST has developed a roadmap for oxy-fuel technology THE CURRENT STATUS OF OXY- development in China (see Figure 2). FUEL TECHNOLOGY IN CHINA Laboratory- and Small-Scale Tests The foundation for Chinese oxy-fuel combustion research began in the mid-1990s. Huazhong University of Science and Table 4 provides an overview of the oxy-fuel combustion

Technology (HUST) and Southeast University were the first small test systems (>10 kWth) that China has built or plans institutions to focus on the desulfurization mechanisms and to build. Overall, there are two main approaches to oxy-fuel combustion properties of oxy-fuel combustion.4 In 2006, HUST coal combustion (pulverized coal combustion and fluidized obtained the support of the first National High Technology bed combustion). To support the development of the overall Research and Development Program for carbon emissions re- technology and key components, there has been significant duction and the first National Key Basic Research Development oxy-fuel-related research activity and platform constructions.2

TABLE 3. Overview of fundamental oxy-fuel combustion research projects in China

Project Type Project Focus Organization(s) Dates National Key Basic Research Resource utilization and storage with CO - 2 HUST, et al. 2006–2010 Development Program EOR National Key Basic Research Combustion principles and HUST, et al. 2011–2015 Development Program separation technologies for low-cost CO2 National High CO emission reduction with synergistic Technology Research and 2 HUST 2005–2008 pollutant removal for coal combustion Development Program National High O /CO cycle combustion equipment Technology Research and 2 2 HUST, et al. 2009–2011 and system optimization Development Program National Science and Key technology and equipment R&D and HUST, DBC, SASE 2011–2014 Technology Support Program for 35-MW oxy-fuel carbon capture National Natural Science New concepts and methods for CO 2 HUST 2011–2014 Fund Key Project enrichment through oxy-fuel combustion National Special Project for U.S.-Chinese advanced coal technology International Scientific and HUST, Tsinghua University, et al. 2012–2014 cooperation Technological Cooperation National Special Project for Cooperative research on large-scale carbon HUST, Institute of Rock and Soil International Scientific and 2011–2013 capture and storage Mechanics, CAS Technological Cooperation Shenhua Group major Megatonne coal-fired HUST 2012–2014 science and technology project carbon capture demonstration

Notes: DBC = Dongfang Boiler Group Co., Ltd; SASE = Sichuan Air Separation Equipment Co., Ltd; CAS = Chinese Academy of Sciences

www.cornerstonemag.net 63 TECHNOLOGY FRONTIERS

200–600 MWe ≥Million tonnes/yr 40 MWth plant CO2-EOR 2.5 MWth CFB Commercial-scale Fundamental 50 kWth oxyfuel boiler burner, long-term study Oxy-CFB pilot In-bed head exchanger operation

1995 2005 2008 2011 2012 2013 2014 2015–2020

300 kWth PC pilot 3 MWth PC pilot 35 MWth plant Burner development, 7000 tonnes CO2/yr 0.1 million tonnes CO2/yr capture data collection, optimization, full chain validation ASU-CPU ASU-CPU-power generation and thermal design coupling FGC and drying integration and optimization FIGURE 2. Roadmap for research and development of oxy-fuel technology in China4

In 2006, HUST completed China’s first 300-kWth-test bed for Air Separation Equipment Co., Ltd., and Jiuda (Yingcheng) Salt oxy-fuel combustion and pollutant removal, achieving the Co., Ltd. The project involved rebuilding a 12-MWe oxy-fuel objective of enriching high concentrations of 2CO (95%) and boiler in the salt company’s power plant. The system uses a removing 85% of NO and 90% of SO . x 2 swirl combustion system positioned on the front wall and is equipped with a cryogenic air separation system. The design In 2011, HUST completed construction of China’s first 3-MWth oxy-fuel whole process test platform in Wuhan (see Figure 3). of the boiler and system is compatible with oxy-fuel combus- This platform is currently China’s largest capacity oxy-fuel test tion. Evaluation tests can be conducted on air combustion as platform, with a heat input of 3 MWth and an annual CO2 cap- well as dry and wet circulation oxy-fuel combustion. After con- ture capacity of up to 7000 tonnes. This system first separates struction is complete, the pilot is expected to achieve a flue oxygen from air, then enriches, compresses, and purifies the gas CO2 concentration higher than 80% and a CO2 capture rate CO2 generated during combustion. Thus the testing platform greater than 90% at a CO2 capture capacity of 100,000 tonnes/ incorporates the comprehensive oxy-fuel combustion process. year. The captured CO can be stored in the mine shafts of the The system was designed in accordance with industry stan- 2 disused salt mine. In addition, some of the CO can also be dards, and therefore possesses the capacity for deployment at 2 increased scale. A number of key technological breakthroughs used in the removal of calcium and magnesium during the salt were achieved during the design, construction, and commis- manufacturing process. The project and its commissioning are sioning of the system. expected to be completed by the end of 2014. CO2 capture, utilization, and storage (CCUS) will be incorporated during the Integrating the advantages and features of a circulating flu- second phase. idized bed, Southeast University has conducted systematic studies of CFB oxy-fuel technology.6,7 A CFB oxy-fuel pilot test installation (50 kWth) was constructed, which was the first in China to genuinely achieve flue gas recirculation and the first internationally to be able to achieve wet flue gas circulation.

The 2.5-MWth circulating fluidized bed oxy-fuel test system that Southeast University has built in partnership with B&W has been fully constructed and is currently being commissioned.

Industrial Pilots

In May 2011, HUST launched an industrial 12-MWe oxy-fuel pilot project (see Figure 4). The construction of this project was financially supported by China’s Ministry of Science and FIGURE 3. 3-MWth oxy-fuel comprehensive process test system Technology, Dongfang Boiler Group Co., Ltd. (DBC), Sichuan (HUST)

64 TABLE 4. Overview of China’s oxy-fuel combustion small test systems (>10 kWth)

Organization Thermal Power (MWth) Furnace Type, Fuel Completion Year HUST 0.3 Vertical pulverized, coal 2006 HUST 3 Front wall pulverized, coal 2011 Vertical one-dimensional Tsinghua University 0.025 2008 pulverized coal furnace Zhejiang University 0.020 Fluidized bed, no flue gas circulation, coal 2004 Zhejiang University 2 Pulverized coal furnace 2010 North China Electric 0.025 Pressurized bubbling bed, coal 2011 Power University Southeast University 0.050 Fluidized bed, coal 2011 Southeast University 2.5 Fluidized bed, coal 2014 Institute of Engineering Thermophysics, Chinese 0.100 Fluidized bed, coal 2013 Academy of Sciences Institute of Engineering Thermophysics, Chinese 1 Fluidized bed, coal and semi-coke Under construction Academy of Sciences

Demonstration-Scale Projects project aims to provide design and technology safeguards for the independent design, construction, and operation of Chinese companies are also actively preparing to launch large- megatonne-scale oxy-fuel projects. HUST, Dongfang Boiler scale oxy-fuel technology demonstration projects. Table 5 Group Co., Ltd., and Southwest Electric Power Design Institute provides an overview of such projects. took part in the research for this project, which was officially launched in November 2012. To date, the project has involved In March 2012, Shenhua Group announced a project to comparing various options for new build and retrofit, technical and economic evaluations, and preliminary research into integrate oxy-fuel combustion and carbon capture at the key equipment such as boilers, burners, and smoke coolers. megatonne scale into a coal-fired power plant. To date more than 70 million RMB (US$11.5 million) has been invested. This Shanxi International Energy Group Ltd. (SIEG) has also announced a cooperative agreement with Air Products, under

which Air Products’ exclusive oxy-fuel CO2 purification tech-

nology will be applied to SIEG’s 350-MWe oxy-fuel power generation demonstration project. Currently a feasibility study and the conceptual design of the installation are being completed. This project is based at SIEG’s power plant in Taiyuan,

Shanxi and will be used to provide purified CO2 emissions for utilization and storage.

On 21 September 2011, China Datang Corporation signed a memorandum of understanding with France’s Alstom, form- ing a long-term strategic partnership to jointly develop CCS pilot projects in China. Under the memorandum, Alstom and China Datang Corporation will collaborate to develop two coal-fired power plant CCS demonstration projects. Of these,

the 350-MWe coal-fired power plant located in Daqing will use

FIGURE 4. Picture of 12-MWe semi-industrial oxy-fuel pilot Alstom’s oxy-fuel technology. A feasibility study is currently installation (HUST) being carried out.

www.cornerstonemag.net 65 TECHNOLOGY FRONTIERS

TABLE 5. Demonstration-scale oxy-fuel pilot projects in China

Project Owner/ Scale and Progress and Planned Technology Source Power Plant Parameters Construction Start Time

Shenhua Group 200 MW Pre-feasibility study completed; e HUST, DBC Shenmu power plant High voltage feasibility study currently underway China Datang Corporation 350 MW Pre-feasibility study completed; e Alstom Daqing power plant Supercritical construction start date yet to be decided Shanxi International Energy Group Ltd. 350 MW Pre-feasibility study completed; e B&W, AP Taiyuan Yangguang Thermoelectric Supercritical construction start date yet to be decided 170 MW Xinjiang Guanghui New Energy e Jupiter Pre-feasibility study underway High voltage

Xinjiang Guanghui New Energy Co., Ltd. has signed a strategic demonstration projects, technology research and development, cooperation agreement with the U.S.-based Jupiter Oxygen environmental monitoring, storage uses, policies and regula- Corporation for a carbon capture, energy conservation, and tions, and international cooperation. emissions reduction project. Jupiter plans to invest US$200 million in collaborating with Xinjiang Guanghui New Energy REFERENCES Co., Ltd. to build and develop a carbon capture and boiler retrofit project. Through this technical cooperation, Xinjiang 1. Abraham, B.M. (1982). Coal-oxygen process provides CO2 for enhanced oil recovery. Oil and Gas Journal, 80(11), 68–75. Guanghui New Energy is expected to be able to reduce CO2 emissions by about 2.4 million tonnes yearly at its plant that 2. Buhre, B.J.P., Elliott, L.K., Sheng, C.D., Gupta, R.P., & Wall, T.F. (2005). Oxy-fuel combustion technology for coal-fired power produces 1.2 million tonnes of methanol and 800,000 tonnes generation. Progress in Energy and Combustion Science, 31(4), of dimethyl ether plant each year. 283–307. 3. Wall, T., Stanger, R., & Santos, S. (2011). Demonstrations of coal- fired oxy-fuel technology for carbon capture and storage and OUTLOOK issues with commercial deployment. International Journal of Greenhouse Gas Control, 5(S1), S5–S15. Following 30 years of development, oxy-fuel technology has 4. Zheng, C., Zhao, Y., & Guo, X. (2014). The research and matured and possesses the fundamental characteristics neces- development of oxy-fuel technology in China. Proceedings of sary for commercial application. Importantly, it is suitable for the Chinese Society for Electrical Engineering, 34(23), 3856– existing coal-fired power plants. For China’s coal power-domi- 3864. (In Chinese) 5. Social Development Science and Technology Division, Ministry nated energy mix to achieve greenhouse gas emission reduction of Science and Technology of the People’s Republic of China, et targets, large-scale demonstrations must be launched as soon al. (2011). Technology development report on carbon capture, as possible, to allow for the greatest likelihood for the com- utilization and storage (CCUS) in China. (In Chinese) mercialization of oxy-fuel. At present, China has announced a 6. Duan, L.B., Zhao, C.S., Zhou, W., Qu, C.R., & Chen, X.P. (2011). succession of special CCUS plans. A number of ministries, includ- O2/CO2 coal combustion characteristics in a 50 kW(th) circulating ing the National Development and Reform Commission, Ministry fluidized bed. International Journal of Greenhouse Gas Control, 5, 770–776. of Science and Technology, National Energy Administration, 7. Zhou, W., Zhao, C.S., Duan, L.B., Liu, D.Y., & Chen, X.P. (2011). CFD Ministry of Environmental Protection, and Ministry of Land modeling of oxy-coal combustion in circulating fluidized bed. and Resources, are promoting numerous strategies, including International Journal of Greenhouse Gas Control, 5, 1489–1497.

66 GLOBAL NEWS

Movers & Shakers will change its approach to the resource tax on coal. The country will now levy a resource tax based not on quantity, but on price, which will replace the previous quantity-based approach. Mitsubishi Corporation announced the opening of the The resource tax rate will be 2–10%; the exact amount will be Caval Ridge Coal Mine in Queensland, Australia. Run by determined by the provincial governments within the given BHP Billiton Mitsubishi Alliance (BMA), Caval Ridge is a new range. The statement also noted that the resource tax will be open-cut mine located in the northern Bowen Basin in Cen- reduced by 30% for coal produced from exhausted coal mines, tral Queensland that has the capacity to produce 5.5 million and by 50% for coal displaced from filling mining. tonnes per year of high-quality metallurgical coal for a mine life of about 60 years. Europe The board of the Rio Tinto Group has extended the tenure of Chief Executive Sam Walsh and Chief Financial Officer Chris The European Council (EC) has adopted several energy targets Lynch, providing a strong endorsement of their leadership, for 2030: reduce greenhouse gas emissions by 40% compared the Group’s strategy, and its focus on driving shareholder with 1990 levels; obtain 27% of its energy from renewable value. sources; and cut energy consumption by 27% compared with projected levels. The final text of the agreement includes a International Outlook flexibility clause stating that the EC will revisit these targets after the UN climate summit in December 2015. The agreement also includes provisions to compensate nations like Australia Poland, which relies on coal for around 90% of its energy.

With the passage of the Emissions Reduction Fund, the Germany Australian government has taken a step toward meeting its greenhouse gas emissions reduction goal of 5% below 2000 levels by 2020. The Emissions Reduction Fund is the center- At risk of missing its greenhouse gas reduction goal of a piece of the Direct Action plan, which replaced the Carbon 40% reduction in emissions by 2020 compared to 1990, Pricing Mechanism repealed in mid-2014. Germany is considering options that include further increasing efficiency and reducing the amount of coal-fired power generation in the country. Canada

On 2 October 2014, India the Boundary Dam CCS project began India’s Supreme Court canceled at least 214 coal licenses operation; the plant because they had been distributed without competitive is the first and only bidding. Coal Minister Piyush Goyal said that the country post-combustion cap- will auction 74 coal-mining licenses to private companies in ture facility operating the next several months. at the scale of about one million tonnes International CO2 each year. According to the head of the Global Carbon Capture and Storage Institute, Brad Page, “This trailblazing The U.S. and China announced an agreement to curb green- project clearly demonstrates that carbon capture and stor- house gas emissions. For its part, the U.S. agreed to reduce age (CCS) is possible on a large scale in the power sector. emissions by 26–28% compared to 2005 levels. China com- Importantly, the lessons learned at Boundary Dam will help mitted to peak its emissions by 2030 and also to obtain 20% progress CCS projects internationally as a vital technology of its energy from non-fossil sources. Under the deal, efforts to meet our climate change challenge.” on low-carbon energy technology development would also be expanded, including continued funding for the U.S.-China China Clean Energy Research Center (CERC). In addition, the U.S. and China have committed to equally fund a commercial-scale

The Ministry of Finance and the State Administration of Taxa- (about one million tonnes CO2 per year) CCUS project under tion released a statement that, from 1 December 2014, China which about 1.4 million m3 of freshwater would be produced.

www.cornerstonemag.net 67 GLOBAL NEWS

Key Meetings & Conferences

lobally there are numerous conferences and meetings geared toward the coal and energy industries. The table below highlights a few such events. If you would like your event listed in Cornerstone, please contact the Executive Editor at [email protected]

Conference Name Dates (2015) Location Website

13th Annual Hilton Singapore, 3–6 Feb www.coalmarketsasia.com/ Coal Markets Conference Singapore 2015 Australian Coal Wollongong, 11–13 Feb www.coalconference.net.au/ Operator’s Conference NSW, Australia www.chinaexhibition.com/Official_Site/11-4609- Beijing and Yinchuan World_CTX_2014_Conference_for_Natural_Gas,_ World CTX 2015 14–17 April (Ningxia Autonomous Liquid_Fuels_and_Petrochemicals_from_Coal,_ Region), China Petcoke_and_Biomass.html World of Coal Ash 4–7 May Nashville, TN, U.S. www.worldofcoalash.org/ Seventh International Con- ference on Clean 17–21 May Kraków, Poland www.cct2015.org/ibis/CCT2015/home Coal Technologies Clearwater 31 May–4 June Clearwater, FL, U.S. www.coaltechnologies.com/ Coal Conference

There are several Coaltrans conferences globally each year. To learn more, visit www.coaltrans.com/calendar.aspx

Meeting Spotlight Although biomass and waste gasification projects are usually significantly smaller in size, they are able to offer As was highlighted in the Autumn 2014 issue of Cornerstone, substantial environmental and/or waste remediation benefits; quite a few presentations were focused in these areas. coal gasification is growing globally, led by coal conversion projects in China. In this meeting spotlight, two conferences The 2015 annual GTC conference will be held in Colorado related to coal conversion are highlighted. The Gasification Springs, CO, U.S. Technologies Council Conference recently concluded and the World CTX Conference will be held early in 2015. World CTX 2015: Focus on Shale Gas Impact on Coal-to-X Development Gasification Technologies Council 2014 Conference The World CTX (Coal-to-X) Conference 2015 will be held in Beijing and Ningxia, China. This year, a focus on shale gas The Gasification Technologies Council (GTC) 2014 Con- will be added to the usual CTX subjects. In the U.S., the ference was held 26–29 October in Washington, DC. This growth of shale gas has placed a damper on coal conver- conference included many internationally known speak- sion projects. Since shale gas development may well spread, understanding the potential impact of shale gas on coal con- ers, most of whom were directly involved with advancing version projects is more necessary than ever. The trifecta of gasification projects. With the rapid upsurge in gasifica- considerations related to the environment, economics, and tion projects in China in recent years, many presentations energy security will impede or advance coal conversion in a focused on specific projects. These projects highlighted the changing global energy sector; this will be the focus of the wide range of potential products from coal gasification from next World CTX conference. The conference website and olefins to substitute natural gas to power. additional information are provided in the table above.

68 Recent Select Publications From the WCA

Mercury Control for Coal-Derived Gas Streams Looking Into the Future for Coal — Wiley-VCH — This newly published textbook covers technologies for the detection, capture, and regulation of The World Coal Association (WCA) and Assocarboni jointly mercury evolved from the combustion or gasification of coal. held a workshop in Rome on 18 November, bringing The information in this together global energy and environment leaders to discuss textbook is largely based the future global role of coal, practical action that can be on the successful U.S. taken to reduce emissions, and the energy challenges facing Department of Energy policymakers in Europe. Mercury Program and includes contributions The workshop “Looking into the Future for Coal” featured from an internation- presentations from representatives from the Australian, ally acclaimed group of experts, edited by Evan Indonesian, and Italian governments. A keynote speech J. Granite, Henry W. was given by the UNFCCC COP President Marcin Korolec, Pennline, and Constance Poland’s State Secretary for the Environment, responsible Senior. More informa- for Climate Policy. tion is available at www. wiley.com/WileyCDA/ The workshop built on the WCA’s Warsaw Communi- WileyTitle/pro qué, developed with the Polish Ministry of Economy and ductCd-3527329498. launched alongside COP19 in November 2013. The Commu- html niqué outlined practical steps that can be taken to tackle climate change and enable coal to continue to play its vital World Energy Outlook 2014 — International Energy role as an affordable, abundant, easily accessible source of Agency — For the first time, the IEA’s WEO will make projec- energy. tions to 2040 throughout the energy sector. Other specific topics covered in WEO Presentations and discussions at the workshop made clear 2014 include a look that most people are expecting a deal out of COP21 in Paris at whether oil output in 2015. There was support for the coal industry being an from North America active, constructive stakeholder and for the industry to can reduce fluctuations more fully promote the role of technology in reducing envi- amid abundance, the ronmental impacts from coal; this includes high-efficiency, potential effects of low-emissions (HELE) coal technology and carbon capture, expanding global LNG, utilization, and storage (CCUS). Participants also agreed that the effect of efficiency the industry should develop a more compelling narrative on regional energy pri- about coal, so that the broader community better under- ces, how energy can stands the vital role coal plays globally. improve life in sub- Saharan Africa, and Further information is available at www.worldcoal.org much more. WEO 2014 is available for purchase Divestment and the Future Role of Coal from www.iea.org/w/ bookshop/477-World_ The World Coal Association has published the latest in its Energy_Outlook_2014 series of “Coal Matters” fact sheets. Coal Matters - Divest- ment and the future role of coal looks at divestment Corrigendum: Volume 2, Issue 3: Page 12: In the figure campaigns and challenges the arguments being made showing potential uses for gasification “hydrogen for oil against the coal industry. refining” was listed twice. The lower term should have been “substitute natural gas”. Page 27: The caption under The fact sheet reviews growing energy demand and projec- the AP Image read, “Nabaj Sarif”, but should have read tions about the future of coal and looks at the role of coal “Nawaz Sharif”. in energy and modern infrastructure. The fact sheet also

www.cornerstonemag.net 69 GLOBAL NEWS

shows that markets are already managing any risks associ- discussed the future development of the international coal ated with fossil fuel investments. industry and other related subjects.

Technology has a huge role to play in reducing environmental Mr. Kenyon-Slaney acknowledged Shenhua Group’s con- impacts from the use of coal. The fact sheet looks at high- tribution to the WCA through the continued support of efficiency, low-emissions coal technology, carbon capture, Cornerstone and the Strategic Research Institute. Later, the utilization, and storage along with actions and investments WCA Chairman visited the Shenhua Science and Technology

taken by the coal industry to reduce CO2 emissions. Research Institute, the Shendong coal mine, and the Zhun- geer coal mine. By definition, divestment requires a change in ownership of assets: Institutes and individuals may sell their shares, but can only do this if other institutes and individuals buy these same shares. In other words, divestment does nothing to affect the demand for or use of fossil fuels.

Divestment campaigns aim to create the very risks they warn of in order to undermine investor confidence and deprive fossil fuel producers of the finance necessary to operate their businesses. However, forecasts show that demand for coal will continue to grow. The priority should therefore be how we access the benefits of coal while minimizing environmental impacts. For developing countries in need of energy, divestment campaigns can have serious consequences. Divestment will do nothing to address shared Making Mines Smarter and Safer global priorities on economic development and reducing GHG emissions and will, instead, hinder efforts to alleviate Recently Harvard Business Review (HBR) highlighted how energy poverty, particularly in developing countries where smart, connected products are transforming competi- coal is fueling economic development. tion and changing industries globally. The mining industry is no different. As part of the study, HBR highlighted how Technology, including efficiency improvements and CCUS, Joy Global, as a leading mining equipment manufacturer, has a vital role to play in offers the ability to monitor operating conditions, safety ensuring we can meet our parameters, and predict equipment servicing needs in the future energy and infra- challenging operating conditions of underground mines. structure needs as cleanly In fact, Joy Global is able to monitor service indicators for and sustainably as possible. fleets of equipment in different mines—even if the equip- This requires responsible ment is spread across multiple countries. For the full case investment decisions and study, visit hbr.org/2014/11/strategic-choices-in-building- balanced energy policies. the-smart-connected-mine/ar/1

A copy of Coal Matters – Divestment and the future role of coal can be down- loaded from the WCA website: www.worldcoal.org

Meeting of the Minds

On 3 November 2014, the Chairman of the World Coal Association, and Rio Tinto Chief Executive, Energy, Harry Kenyon-Slaney, visited Shenhua Group and met with the Chairman of Shenhua Group, Zhang Yuzhuo. The leaders

70 LETTERS

the region’s options for energy sources. Through the use of VOLUME 2, ISSUE 2 carbon capture and sequestration, as well as other clean coal technologies, Western Europe can simultaneously reduce AN ANALYSIS OF THE INTERDEPENDENCE its dependence on natural gas imports, as well as increase BETWEEN CHINA’S ECONOMY AND COAL the recovery rate from its North Sea oil reserves, and not he authors of this article analyzed the contribution increase its greenhouse gas emissions. While not neglecting of coal to China’s economy based on several metrics. long-run climate concerns, an increased use of new technolo- Much-needed proof was provided regarding the value gies to utilize the ample and widely available sources of coal T would enable Europe to respond to its short-term energy coal can provide. China has become the world’s second largest economy, continuing to grow at full steam, and is also the security needs while not burdening its economies with exces- largest coal producer and consumer. The country’s economic sive energy price increases. There are only a limited number growth and its reliance on coal are not unrelated as coal has of options for energy, and with energy goals that include a contributed tremendously to China’s development. This arti- reduced reliance on nuclear power and less dependence on cle provides an understanding as to why developing countries Russian natural gas, the answer to Western Europe’s energy continue to rely on coal as a leading energy source. Those that problem clearly involves a greater use of coal. undermine the value of the coal industry may do well to con- John Jelacic sider the information presented in this article. Independent Energy and Economic Analyst

After an analysis of the correlation between historical eco- his article is overly ambitious in its assertions of what is nomic data and coal production and consumption, the authors possible regarding bringing online coal-fired power plants calculated a positive correlation coefficient. The core of their Tthat are no longer operating in the EU. One example is analysis was the coal-dependence index that they defined the statement that some plants currently idled, such as those using four indices, which ultimately explained the interde- in the UK, could be “brought back online relatively quickly”. In pendency of coal and China’s GDP. As we know, coal provides many cases such plants are not actually idled, but completely more than 70% of total primary energy consumption and more shut down. In some cases these plants have even been partly than 70% of total power output in China. The authors demon- or fully demolished. Even for those plants still standing, they strated how coal is an irreplaceable energy source that helps could not be simply placed back into service. Their opera- ensure energy security, maintain social stability, and promote tion would be illegal as many of these plants do not have the the development of national and local economies. required environmental controls to operate legally today. In fact, this article does not take into account EU emission regu- From a global perspective, the relationship between coal and lations, including the Industrial Emissions Directive—this will economics remains strong. Although the global coal indus- be enforced as of 2016 and will actually result in the closure of try is facing a downward trend, characterized by lower coal additional plants. Generally, the strategy laid out in this article prices, I continue to believe that the perspective of the coal cannot realistically be followed under the current regulatory industry should be based on the fact that coal consumption environment in the UK and greater EU. will continue to grow, especially in developing countries. Drawing from the data in this article, I hope that the global Anonymous coal industry will face the future with optimism and extend its work to realize the cleaner utilization of coal resources for the Response: The article was based on a dynamic situation benefit of all. regarding the state of coal-fired power plants in the EU; unfor- tunately, some plants have been idled or demolished since the Zhang Songfeng original research was completed. However, the reader brings Researcher up a valuable point that the longer European leaders wait to Academy of Macroeconomic Research act, the more difficult it will be to reduce reliance on Russian National Development and Reform Commission energy supplies. Thus, the door of opportunity is closing and I suggest there should be an immediate moratorium on demol- VOLUME 2, ISSUE 3 ishing any coal-fired power plants in Europe. For instance, in the UK, potential power generation sources such as the 1000- A COAL-BASED STRATEGY TO REDUCE EUROPE’S MW Ferrybridge plant or the 350-MW Uskmouth plant must DEPENDENCE ON RUSSIAN ENERGY IMPORTS be protected.

ith Western Europe facing the apparently intractable The research and the article did take into account the envi- problem of its dependency on Russian natural gas ronmental upgrades that would be necessary to bring idled Wimports, it is refreshing to read a rational analysis coal-fired plants back online. For example, I noted on p. 46, that reminds us that an increased use of coal could broaden “It may be necessary to add more SO2 and NOx controls, and

www.cornerstonemag.net 71 LETTERS

perhaps other environmental upgrades, to the units.” While is commercial and supported by CO2 prices in the EU ETS. considerable investment may be required, adding environmental controls for criteria emissions include applying completely Finally, it is important to make clear that the article presented understood, fully commercial technologies already deployed an ambitious strategy to increase the energy security of the EU. throughout Europe and the world. There may be some regulations that are not compatible with the strategy, but it is worth weighing the value of a carbon- Regarding greenhouse gas emissions, the article showed that neutral strategy that improves energy security. Regulations CTG with CO2-EOR actually resulted in lower greenhouse gas can be modified more easily than global energy reserves. emissions compared to continuing to rely on the leaky and poorly maintained natural gas pipelines from Russia. As well, Roger Bezdek there may be additional opportunities to reduce greenhouse President gas emissions with CCUS from coal-fired power plants when it Management Information Services, Inc.

TO SUBMIT A LETTER TO THE EDITOR, EMAIL [email protected] OR [email protected] (CHINESE).

We’re in the process of planning the editorial schedule for 2015.

We’d appreciate hearing from you regarding what topics you would like us to cover.

We’re looking for any and all feedback from our readers.

Cornerstone aims to be inclusive to all things related to coal and energy, especially those pieces that are focused on scientifically derived solutions for the challenges associated with ever increasing energy demand. Our goal is to include diverse material, such as interviews, letters, op-ed editorials, technical articles, global news, conference listings, etc. If you are interested in contributing or have suggestions about what we should cover, please don’t hesitate to contact the editorial team.

If you have a suggestion, email the editorial team at [email protected] (English) or [email protected] (Chinese)

72 VOLUME 2 AUTHOR INDEX

Author(s) Title Pages Volume 2, Issue 1, Spring 2014 Michael Hightower Reducing Energy’s Water Footprint: Driving a Sustainable Energy Future 4–8 Diego Rodriguez Thirsty Energy: Integrated Energy-Water Planning for a Sustainable Future 9–11 Holly Krutka Exploring Global Energy Challenges: Exclusive Interview with Nobuo Tanaka 12–14 Wang Xianzheng Advancing China’s Coal Industry 15–18 Aleksandra Tomczak What to Watch in 2014: Policy Developments That Will Shape the Coal Industry 19–25 Tianyi Luo, Betsy Otto, Identifying the Global Coal Industry’s Water Risks 26–31 Tien Shiao, Andrew Maddocks Li Zheng, Pan Lingying, Liu Pei, Assessing Water Issues in China’s Coal Industry 32–36 Ma Linwei Rangan Banerjee Coal-Based Electricity Generation in India 37–42

Merched Azzi, Paul Feron Considering Emissions From Amine-Based CO2 Capture Before Deployment 43–46 Barbara Carney, Erik Shuster Exploring the Possibilities: The NETL Power Plant Water Program 47–51 Sean Bushart Advanced Cooling Technologies for Water Savings at Coal-Fired Power Plants 52–57 Anne Carpenter Water-Saving FGD Technologies 58–63 Chen Yinbiao, Zhang Jianli Supplying Water to Power Plants with Desalination Technology 64–68 Daman Walia, Sahika Yurek Moving Coal Up the Value Chain 69–73 Nikki Fisher, Thubendran Naidoo Turning a Liability into an Asset 74–77 Okty Damayanti Connecting Indonesian Communities to Clean Water 78–79 Volume 2, Issue 2, Summer 2014 Anthony Hodge Shifting the Paradigms of Health and Safety in Mining 4–8 Milton Catelin Commitment to Safety 9–10 Modern Energy: The “Golden Thread” That Connects Gregory H. Boyce 11–14 People, Economies, and Progress Zhang Kehui Studying the Dominance of Coal in China’s Energy Mix 15–20 Jim Spiers Hedging Carbon 21–24 Nicholas Newman Advancing the Alleviation of Energy Poverty 25–29 Anil Razdan Energy Poverty in India and What’s Needed to Address It 30–35 Nikki Fisher Balancing South Africa’s Energy Poverty and Climate Change Commitments 36–38 Aleksandra Tomczak Europe Struggles to Pay Its Energy Bill 39–41 Shenhua Group’s Preemptive Risk Control System: Hao Gui 42–46 An Effective Approach for Coal Mine Safety Management Melanie Stutsel Evaluating Safety and Health in Australia’s Mining Sector 47–52 CORESafety®: A System to Overcome the Plateau in Bruce Watzman 53–56 U.S. Mine Safety and Health Management Aaron Leopold Sustainable Charcoal: A Key Component of Total Energy Access? 57–61 Xie Heping, Wu Gang, Liu Hong An Analysis of the Interdependence Between China’s Economy and Coal 62–66 Yuan Liang Synergetic Technologies for Coal and Gas Extraction in China 67–71 Uichiro Yoshimura, Toshiro Matsuda The Global Need for Clean Coal Technologies and J-COAL’s Roadmap to Get There 72–77

www.cornerstonemag.net 73 VOLUME 2 AUTHOR INDEX

Author(s) Title Pages Volume 2, Issue 3, Autumn 2014 Gasification Can Help Meet the World’s Growing Demand Alison Kerester 4–12 for Cleaner Energy and Products Laura Miller The Drivers and Status of the Texas Clean Energy Project 13–18 Carbon Pollution Standards for New and Existing Power Plants Kyle Aarons 19–23 and Their Impact on Carbon Capture and Storage A.M. Shah India Re-energized 24–28 Ni Weidou, Song Shizhong, Developing High-Efficiency, Low-Carbon, Clean Coal in China 29–33 Wang Minghua A Coal-Based Strategy to Reduce Europe’s Dependence Roger Bezdek 34–39 on Russian Energy Imports Janet Gellici The Reliability and Resilience of the U.S. Existing Coal Fleet 40–45 Harry Morehead, Juergen Battke Improving the Case for Gasification 46–49 Rob van den Berg, Zhong-Xin Chen, The Shell Coal Gasification Process for Reliable Chemicals, 50–54 Sze-Hong Chua Power, and Liquids Production Carrie Lalou Distributed Power With Advanced Clean Coal Gasification Technology 55–60 Xu Shisen Moving Forward With the Huaneng GreenGen IGCC Demonstration 61–65 Rob Jeffrey, Rosemary Falcon, The Benefits and Challenges Associated With Coal in South Africa 66–70 Andrew Kinghorn Volume 2, Issue 4, Winter 2014 Stephen Mills The Energy Frontier of Combining Coal and Renewable Energy Systems 4–10 The Rise of Electricity: Offering Longevity, Improved Frank Clemente 11–16 Living Standards, and a Healthier Planet Patrick Falwell, Brad Crabtree Understanding the National Enhanced Oil Recovery Initiative 17–20 Benjamin Sporton Developing Country Needs Are Critical to a Global Climate Agreement 21–24 The Flexibility of German Coal-Fired Power Plants Hans-Wilhelm Schiffer 25–30 Amid Increased Renewables Janne Kärki, Antti Arasto Toward Carbon-Negative Power Plants With Biomass Cofiring and CCS 31–35 Christopher Long, Peter Valberg Evolution of Cleaner Solid Fuel Combustion 36–40 Jaquelin Cochran, Debra Lew, Making Coal Flexible: Getting From Baseload to Peaking Plant 41–45 Nikhil Kumar Nigel Bean, Josephine Varney Geothermal Assisted Power Generation for Thermal Power Plants 46–50 Han Jianguo Shenhua’s Development of Digital Mines 51–55 Christopher Munnings, Sarbjit Giddey, Direct Carbon Fuel Cells: 56–60 Sukhvinder Badwal An Ultra-Low Emission Technology for Power Generation Zheng Chuguang Exploring the Status of Oxy-fuel Technology Globally and in China 61–66

74 Coal Classification Industry Approach to Hazard Classification under the Revised MARPOL Convention and the IMSBC Code

The International Maritime Organization (IMO) The reports are available free of charge to WCA has introduced new environmental and health Members. classification criteria for internationally shipped solid bulk cargoes under the International Convention The reports are also available to non-WCA Members to for the Prevention of Pollution from Ships (MARPOL) purchase. If you would like information on purchasing and the International Maritime Solid Bulk Cargoes this package of reports, please email the WCA Team at: (IMSBC) Code. [email protected]

The World Coal Association (WCA), together with You can also get the reports for free if you join the ARCHE - a specialist environmental toxicology WCA. Join today and you can get instant access to consultancy - has prepared a package of reports to this package of reports, along with all the other assist coal companies with complying with the new benefits of membership. If you would like to discuss environmental and health classification requirements. WCA membership options, please get in touch: The package consists of three reports and a summary [email protected] document:

Report 1: New Compliance Requirements of the MARPOL Convention and the IMSBC Code

World Coal Association Report 2: Analysis of Coal Composition, Ecotoxicity 5th Floor, Heddon House and Human Health Hazards 149-151 Regent Street London W1B 4JD, UK +44 (0) 207 851 0052 Report 3: Coal Classification Guidance www.worldcoal.org [email protected]

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CONNECT WITH US Like what you’re reading? Disagree with an author? Have a correction? Email the editors at [email protected] (English) or [email protected] (Chinese). www.cornerstonemag.net In many countries, coal and renewable energy systems are being deployed at greater percentages and, thus, there is increased interest in how to optimally integrate these systems. In fact, there are a significant number of opportunities.