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Comparison of Geothermal with Solar and Wind Power Generation Systems Renewable and Sustainable Energy Reviews 42 (2015) 1464–1474 Contents lists available at ScienceDirect Renewable and Sustainable Energy Reviews journal homepage: www.elsevier.com/locate/rser Comparison of geothermal with solar and wind power generation systems Kewen Li a,b,n, Huiyuan Bian a, Changwei Liu a, Danfeng Zhang a, Yanan Yang a a China University of Geosciences, Beijing, China b Stanford University, Stanford Geothermal Program, Stanford, CA 94305, USA article info abstract Article history: Geothermal, solar and wind are all clean, renewable energies with a huge amount of resources and a Received 10 May 2014 great potential of electricity generation. Geothermal energy had definitely dominated the renewable Received in revised form energy market in terms of the installed electricity power about 30 years ago. The unfortunate fact is that 6 September 2014 the total installed capacity of geothermal electricity has been eclipsed by solar and wind in recent years. Accepted 18 October 2014 In this paper, benefits of using renewable energy resources (RER) have been summarized and attempt has been made to explain the recent trends causing the shift from geothermal energy to solar and wind. Keywords: Cost, payback time, size of power generation, construction time, resource capacity, characteristics of Geothermal energy resource, and other factors were to compare geothermal, solar, and wind power generation systems. Solar Furthermore, historical data from geothermal, solar, and wind industries were collected and analyzed at Wind power generation the global scale. The data from hydropower were also considered in the comparison. Finally, we Comparison proposed suggestions for the geothermal industry to catch up with solar and wind industries. & 2014 Elsevier Ltd. All rights reserved. Contents 1. Introduction.......................................................................................................1464 2. Comparison of resources, installed power and capacity increase . 1466 3. Comparison of cost, efficiency, and environmental impacts . 1468 4. Comparison of social impacts and government barriers . 1468 5. Unit power size and modularization . 1468 6. Solutions to speed up geothermal power growth . 1470 6.1. New technology. 1472 6.2. Co-produced geothermal power from oil and gas fields.............................................................. 1473 6.3. EGS........................................................................................................ 1473 7. Conclusions....................................................................................................... 1473 References............................................................................................................ 1473 1. Introduction keep atmospheric greenhouse gases below 450 ppm in order to keep the temperature rise under a 2 1C target [3]. It seems that this The overdevelopment and consumption of fossil energy is a big challenge. In the coming decades, global environmental resources (FER) have caused environmental and ecological pro- issues will significantly affect patterns of energy use around the blems that impacts our daily lives. Continued dependency on fossil world. Any future efforts to limit carbon emissions are likely to fuels may increase the rate of global warming with disastrous alter the composition of total energy-related carbon emissions by consequences [1]. When the Intergovernmental Panel on Climate energy sources. Air pollution is becoming an important environ- Change (IPCC) issued its 2007 assessment [2], it recommended to mental concern in some of the developing countries. In this regard, renewable and clean energy resources (RCER) are becom- n Correspondence address: China University of Geosciences, Beijing, China. ing attractive for sustainable energy development and environ- E-mail address: [email protected] (K. Li). mental pollution mitigation in these countries [4–12]. http://dx.doi.org/10.1016/j.rser.2014.10.049 1364-0321/& 2014 Elsevier Ltd. All rights reserved. K. Li et al. / Renewable and Sustainable Energy Reviews 42 (2015) 1464–1474 1465 Not only do future energy technologies need to be clean and power generation has been considered to compare with hydro- renewable, but they also need to be robust, especially in some power, solar and wind energies in this paper. developing countries such as China [13,14]. The recent heavy fog Trying to find the reason for the stagnant growth in geothermal enveloping a large swathe of Eastern and Central China is a stark power generation, Kubota et al. [15] conducted semi-structured example. There was neither sunshine (no solar energy) nor wind interviews with 26 stakeholders including developers, hot spring (no wind turbine rotating). Furthermore, Beijing was hit 4 times by inn managers, and local government officials. The results showed heavy haze and fog within one month in January 2013. Hundreds that the societal acceptance of geothermal power by local stake- of flights were cancelled and highways were closed. The Beijing holders was the fundamental barrier as it affected almost all other meteorological observatory issued a yellow alert (the highest level barriers, such as financial, technical, and political risks. They alert) for heavy fog on January 22, 2013. thought that a key reason for opposition was identified as The existing energy systems in many countries are not sustain- uncertainty about the reversibility and predictability of the able due to the increasing energy demand triggered by population adverse effects on hot springs and other underground structures expansion and economic growth, as well as short-and long-term by geothermal power production and reinjection of hot water from uncertainty in connection with the availability of resources. A new reservoirs. energy structure with consumption-rationing and high efficiency Evan et al. [24] has assessed the non-combustion based renew- needs to be achieved simultaneously. More emphasis on the use of able electricity generation technologies against a range of sustain- renewable and clean energy sources is important to shift the ability indicators and using data obtained from the literature. The structure of our energy system towards sustainability [15]. cost of electricity, greenhouse gas emissions and the efficiency of Ming et al. [16] analyzed the physical and technical potential of electricity generation were found to have a very wide range for several disrupting technologies that could combat climate change each technology, mainly due to variations in technological options by enhancing outgoing long wave radiation and cooling down the as well as geographical dependence of each renewable energy Earth. The technologies proposed were power-generating systems source. The social impacts were assessed qualitatively based on that were able to transfer heat from the Earth’s surface to the the major individual impacts discussed in literature. It was found upper layers of the troposphere and ultimately to space. The that wind power is the most sustainable, followed by hydropower, economic potential of these technologies is clear, as they simulta- photovoltaic and then geothermal. Dombi et al. [25] assessed the neously produce renewable energy (RE), thus reducing future sustainability of renewable power and heat generation technolo- greenhouse gases emissions, and also are more socially acceptable gies, ten technologies of power generation were examined in a compared to geoengineering. multi-criteria sustainability assessment frame of seven attributes One of the currently practical solutions to the problems caused which were evaluated on the basis of a choice experiment survey. by FER may be the large scale utilization of RE. In recent decade or The results demonstrated that concentrated solar power (CSP), so, RER have grown fast, especially the solar and wind energies hydropower and geothermal power plants were favorable tech- although the utilization of RE is still far from its potential at a nologies for power generation. global scale [17]. The relatively fast growth of using RER might be As analyzed by Resch et al. [26], the theoretical and technical because of their many benefits: (1) reducing the emission of CO2 potentials of RER are huge compared to the status quo of energy as well as other greenhouse gases and improving environment; consumption in general and the current deployment of RER, (2) assisting with energy independence in many countries without respectively. From a theoretical perspective RER could contribute enough fossil energy resources; (3) diversifying resources of to meet more than 300,000 times the current overall primary energy production and improving the structure of the existing energy demand at global scale. They also pointed out, by con- energetic systems; (4) contributing to a sustainable development; sidering technical constraints still the potential remains 16 times (5) increasing local labor employment; (6) reducing risks and higher than current needs, but at present (2008) RER cover disasters (for example, explosions of natural gas pipes) caused by approximately only 13.1%. De Vries et al. [27] investigated the using FER. RER potential for the first-half of the 21st century at a global level. As summarized in Renewables 2014: Global Status Report [17], Unfortunately geothermal energy was not considered. Only wind, hydropower rose by 4% to approximately 1000 gigawatts (GW), solar-PV and biomass were included. while other renewables collectively grew nearly 17% to an esti- Haas et
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