The Wind Energy (R)Evolution: a Short Review of a Long History

Renewable Energy 36 (2011) 1887e1901

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Renewable Energy

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Review The wind energy (r)evolution: A short review of a long history

John K. Kaldellis*,D.Zaﬁrakis

Lab of Soft Energy Applications & Environmental Protection, TEI of Piraeus, Greece article info abstract

Article history: Although wind energy exploitation dates back ﬁve thousand years ago, contemporary societies are based Received 30 November 2010 almost exclusively on fossil fuels for covering their electrical energy needs. On the other hand, during the Accepted 6 January 2011 last thirty years, security of energy supply and environmental issues have reheated the interest for wind Available online 4 February 2011 energy applications. In this context, the present work traces the long and difﬁcult steps of wind energy development from the California era to the construction of huge offshore wind parks worldwide, Keywords: highlighting the prospects and the main challenges of wind energy applications towards the target of Wind power 1000 GW of wind power by 2030. Global market Ó Technological evolution 2011 Elsevier Ltd. All rights reserved. Economics of wind Environmental impacts Future prospects

1. Introduction both of the aforementioned concepts dictating the future horizontal-axis design approaches later emerging in the 70s. It was centuries ago when the technology of wind energy made One of the most important milestones of the wind energy history its first actual stepsealthough simpler wind devices date back coincides with the USA government involvement in the wind energy thousands of years agoewith the vertical axis windmills found at the research and development (R&D) after the oil crisis of 1973 [6e8]. Persian-Afghan borders around 200 BC and the horizontal-axis Following, in the years between 1973 and 1986, the commercial WT windmills of the Netherlands and the Mediterranean following market evolved from domestic and agricultural (1e25 kW) to utility much later (1300e1875 AD) [1e3]. Further evolution [4] and interconnected wind farm applications (50e600 kW). In this perfection of these systems (Fig.1) was performed in the USA during context, the first large-scale wind energy penetration outbreak was the 19th century, i.e. when over 6 million of small machines were encountered in California [9], where over 16,000 machines, ranging used for water pumping between 1850 and 1970. On the other hand, from 20 to 350 kW (a total of 1.7 GW), were installed between 1981 the first large wind machine to generate electricity (a low speed and and 1990, as a result of the incentives (such as the federal investment high-solidity wind turbine (WT) of 12 kW) was installed in Cleve- and energy credits) given by the USA government. In northern land, Ohio, in 1888, while during the late stages of World War I, use of Europe on the other hand, wind farm installations increased steadily 25 kW machines throughout Denmark was widespread. Further through the 80s and the 90s, with the higher cost of electricity and development of wind generators in the USA was inspired by the the excellent wind resources leading to the creation of a small but design of airplane propellers and monoplane wings, while subse- stable market. After 1990 most market activity shifted to Europe quent efforts in Denmark, France, Germany, and the UK (during the [10], with the last twenty years bringing wind energy at the front line period between 1935 and 1970) showed that large-scale WTs could of the global scene with major players from all world regions. work. European developments continued after World War II. In In this context, in the current work, a short review of the Denmark, the Gedser mill 200 kW three-bladed upwind rotor WT developments noted in the field of wind energy at the global level is operated successfully until the early 1960s [5], while in Germany, undertaken, with special emphasis given on the major fields of a series of advanced horizontal-axis designs were developed, with global market facts, technology issues, economics, environmental performance, wind energy prospects and R&D. Highlights and some insight for each of the fields are currently presented, while special * Corresponding author. Lab of Soft Energy Applications & Environmental attention is given to the European achievements. More specifically, Protection, TEI of Piraeus, P.O. Box 41046, Athens 12201, Greece. Tel.: þ30 210 in the global market facts’ section, the time evolution of the global 5381237; fax: þ30 210 5381467. E-mail address: [email protected] (J.K. Kaldellis). wind power capacity and energy generation are presented along URL: http://www.sealab.gr/ with the leading markets of today and the most important EU and

0960-1481/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.renene.2011.01.002 Fig. 1. From the early stages of wind energy exploitation to the outbreak of California (Source: [4]).

Time Evolution of Global and European Wind Power Capacity

160000 Europe 80% World 140000 EU Contribution 75%

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100000 65%

80000 60%

60000 55% EU Contribution 40000 50% Installed Capacity (MW) 20000 45%

0 40%

001 006 1996 1997 1998 1999 2000 2 2002 2003 2004 2005 2 2007 2008 2009

Twenty Year Time Evolution of Global Wind Energy Generation (1989-2007) 180 90% World 160 Europe 80% 140 United States 70% Europe Share 120 60%

100 50%

80 40%

60 30% Share Europe

40 20%

20 10% Wind Energy Generation (TWh) 0 0%

997 002 1990 1991 1992 1993 1994 1995 1996 1 1998 1999 2000 2001 2 2003 2004 2005 2006 2007

Fig. 2. Time evolution of global and European wind power capacity and wind energy generation (based on data from [11e14]). J.K. Kaldellis, D. Zaﬁrakis / Renewable Energy 36 (2011) 1887e1901 1889

Fig. 3. The gradual shift of wind energy generation between world regions (based on data from [14]). world wind power facts. Following, in the technology issues section, discussion concerning the upscale of machines, the main technological characteristics of contemporary WTs and issues such as grid integration, efﬁciency of the machines and expansion of the small scale machines’ industry is undertaken. In the economics section, issues such as the time evolution of investment costs, the costs of both onshore and offshore applications, the effect of ﬁnancial support mechanisms, the employment opportunities appearing due to the expansion of the wind energy industry as well as a comparison with other power generation technologies are all presented. Next, in the environmental performance section, a short notice on the impacts of wind energy is provided while attention is given to the externalities avoided and the social acceptance levels of wind power. Finally, in the wind energy prospects and R&D part, a summary of future targets is provided at both the market and the technological level.

2. Global market facts

According to the latest ofﬁcial data [11e14], the global wind power capacity was increased during 2009 by 37.4 GW (Fig. 2a), thus reaching a total of almost 158 GW on the basis of remarkable development rates exhibited for the past twenty years. Europe is at the moment approaching, if not yet exceeded, 80 GW and is now heading to offshore applications [15]. In fact, it is since the mid-90s that the EU market corresponds to over 50% of the global installed capacity, that is nowadays said to yield an overall of 260TWh/year. In this context, although the EU held only 20% of the word wind energy generation in the early 90s (Fig. 2b), production of European wind parks managed to even reach 70% in the years after 2000, with a production of 100TWh/year already achieved by the end of Fig. 4. Country and regional distribution of wind power capacity installed in 2009 2007. (based on data from [13]). 1890 J.K. Kaldellis, D. Zaﬁrakis / Renewable Energy 36 (2011) 1887e1901

Fig. 5. Time evolution of wind power capacity in major EU markets (based on data from [11]).

However, restart of the USA market [16] and development of the energy production attributed to North America in the early 90’s wind energy industry in China [17] have considerably reduced the shrank to 20% within a decade’s time, while for the region of Asia & aforementioned numbers during the recent years to a current 60%. Oceania considerable contribution may be encountered since 1995. As a result, the aggregate share of North America and Asia & Oce- Concerning the present status of wind power capacity (Fig. 4a), ania in 2007 corresponded to an approximate 38% of the world the USA managed during 2009 to add a new 40% over its cumula- wind energy production (Fig. 3). In the meantime, 80% of wind tive capacity. At the same time the Chinese achieved to install

Fig. 6. Time evolution of annual and cumulative power capacity installations in the EU by technology type (based on data from [11]). J.K. Kaldellis, D. Zaﬁrakis / Renewable Energy 36 (2011) 1887e1901 1891

Fig. 7. Wind energy contribution to the gross electricity generation of EU countries (based on data from [19]). almost 14 GW, i.e. 20% and 40% of the EU and the USA cumulative terms of cumulative installations (Fig. 6b), European wind farms capacity respectively, which leads to an aggregate (USA and China) exceed oil-based generation by 20 GW and are down by 50 GW of 62% of the 2009 capacity. As a result, China has reached the when compared to nuclear power. In fact, the developing rate of second place of the world ranking table together with the long- wind energy capacity is only comparable to the respective of term leader of the EU, i.e. Germany. Besides, at the regional level natural gas installations, with the remarkable growth of photo- (Fig. 4b), Asia has managed to marginally exceed the North Amer- voltaic plants also designating the shift attempted in the EU to icans in terms of cumulative capacity, while the EU is still the world clean power generation technologies. leader with almost 50%. In this context, contribution shares of wind energy production At the same time, at the European level (Fig. 5) Germany to the gross electricity generation of certain EU countries already (25.8 GW) and Spain (19.1 GW) are now followed by Italy exceed 10% (e.g. Denmark, Portugal and Spain) [19], while for the (4850 MW), France (4492 MW), UK (4051 MW), Portugal (3535 MW) Danish approximately 20% should be considered, with the respec- and Denmark (3465), with the latter presenting a long-term stag- tive EU average kept at 4.1% (Fig. 7). Nevertheless, shift to offshore nation that calls for the improvement of the local legislation [18] attempted by many European countries [20,21] (1.5 GW already in although considerable exploitation of the local wind potential has operation in Denmark and the UK), with short-term plans of 33 GW already been achieved. On the other hand, France and Portugal by 2015 mainly supported by Germany and UK (Fig. 8), shall further present remarkable developing rates since 2000, while for Italy and increase the contribution shares of EU wind farms. Netherlands the local wind energy market encountered an earlier Summarizing, according to the latest ofﬁcial data, the EU still start (i.e. since 1990) with analogous results only for the case of Italy. remains the world leader, although the USA made a considerable Further, what is also interesting to see is the time evolution of come-back with over 10 GW installed in 2009. Meanwhile, China generating capacity of all technologies in the EU during the time persists on its outstanding growth rates, each year doubling its from 1995 to 2009. As one may see in Fig. 6a, during the last two cumulative capacity, and seems ready to overtake the ﬁrst place in the years, new wind power capacity exceeds any other technology with world ranking table. On top of these, India following a steady growth more than 10 GW of wind power installed in 2009. Additionally, in rate [22] is the China’s most important ally, adding more than 10 GW

Offshore Wind Energy Development Prospects in Europe 1600 12000

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1200 In Operation 9000 Under Construction 1000 7500 Planned (2015) 800 6000

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Construction (MW) 400 3000 In Operation & Under 200 1500 Planned Installations (MW) Planned Installations 0 0 UK Italy Spain Ireland France Poland Finland Norway Sweden Belgium Denmark Germany Netherlands Country

Fig. 8. Current status and future plans for the operation of offshore wind energy applications in the EU (based on data from [21]). 1892 J.K. Kaldellis, D. Zaﬁrakis / Renewable Energy 36 (2011) 1887e1901

Fig. 9. Time evolution of size scale-up (Source: [30]) and the largest commercial wind turbines of nowadays. for the Asian region. Besides, after a long stagnating period Australia by some of the manufacturers (even at the levels of 7 MW) e , while managed to install almost 1 GW during 2008e09 [23], thus increasing designs of machines that will exceed the nominal power of 10 MW the Paciﬁc capacity at more than 2 GW. On the other hand, in the Latin are already underway. America, noteworthy is only the development encountered in Brazil, Meanwhile, during the evolution of technology, multi-bladed Chile, Mexico and Costa Rica, summing up however to a total of only turbines are found to be constrained to water pumping applica- 1GW[24]. Finally, Egypt, Morocco and Tunisia [25] are the only active tions. On the other hand, among the types of electricity generation, African countries (more than 0.7 GW), with Iran being the only Middle the three-bladed WTs prevailed over the respective single- and East country found to considerably exploit its local wind potential (w100 MW) [26].

Time Evolution of Pitch & Stall Regulated Machines' Shares 4,0 3. Technology issues 3,5 The development of contemporary WTs in the course of time 3,0 e fl [27 29] may be re ected by the gradual upscale of machines, based 2,5 on the rationale for better land exploitation, presence of scale 2,0 economies, reduced maintenance and operation (M&O) requirements and past funding development programs [1] pushing 1,5 towards the development of big-scale machines. On the other hand, 1,0 Ratio of Pitch / Stall a stabilizing trend is noted during the recent years that has put an 0,5 end to the exponential increase of the rotor diameter met in the 0,0 first two decades (Fig. 9a) [30]. As a result, WTs of nowadays are 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 e mainly in the order of 2 3 MW, although larger scale machines that Year are already commercial do exist (Fig. 9b). Contrariwise, the shift to offshore applications calls for multi-MW solutionsealready offered Fig. 10. Time evolution of the pitch to stall ratio (Source: [30]). J.K. Kaldellis, D. Zafirakis / Renewable Energy 36 (2011) 1887e1901 1893

Time Evolution of the Mean Annual CF on the EU & the Global Level 21%

20%

19%

18%

17% Mean Capacity Factor Factor Capacity Mean 16% EU World

15% 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 Year

Long-Term Capacity Factor of Wind Power Installations in European Countries (1990-2008) 30%

25%

20%

15%

10% Long-Term CF 5%

0% Italy Spain Latvia Turkey Ireland France Poland Austria Croatia Finland Greece Estonia Sweden Belgium Bulgaria Portugal Hungary Slovakia Romania Denmark Lithuania Germany Netherlands Luxembourg Czech Republic Country United Kingdom

Fig. 11. Time evolution of the mean annual CF for the world and the EU wind energy applications (based on data from [14]).

two-bladed machines that appeared to be both less efficient and Denmark where although local wind potential keeps CFs at moderate less accepted concerning their visual impact. Similarly, the inherent values, diffusion of wind parks is remarkable, and countries such as lower efficiency and the cost-ineffectiveness were the main reasons Ireland, Spain and Turkey where the long-term CF is found to exceed for the vertical axis WTs (VAWTs) actually never becoming main- 25% (Fig. 11b). stream, although a new market seems to emerge for the smallest scale VAWTs in building applications [31,32]. Concerning power regulation, pitch control found itself to be gradually more adaptable to new machines, with the ratio of pitch to stall machines increasing from 1:1 (1997) to 4:1 in 2006 (Fig. 10). Following, introduction of the variable speed concept, although inducing extra costs and additional losses in the variable speed drive, allowed for increased energy capture below the rated power area and relief of loads, enhancement of the pitch and smooth power output above the rated power area. In this context, a long term increase of the mean annual capacity factor (CF) met at both the EU and the global level (Fig.11a), exceeding 20% in 2007, reflects the effect of technological improvements, this also including the gradual establishment of pitch control machines. More specifically, although good wind potential areas are now harder to find, exploitation of wind energy per kW has increased due to improved efficiency of contemporary turbines, sophisticated assessment of the local wind potential, considerable reduction of downtime periods, upgrade of networks and operation of offshore applications. In this context, of special interest are countries such as Germany and Fig. 12. Range of applications for small scale wind turbines (based on data from [45]). 1894 J.K. Kaldellis, D. Zafirakis / Renewable Energy 36 (2011) 1887e1901

Time Evolution of the Specific Turnkey Cost of Onshore Wind Farms 4000

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2500

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1000 Specific Cost (Euros/kW) 500

0 1980 1983 1986 1989 1992 1995 1998 2001 2004 Year

Specific Turnkey Cost for Different Countries (2006) 1600 Per Country 1400 Average

1200

1000

800

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400 Specific Cost (Euros/kW) 200

y l k ny n r S tal UK ga a U I ands way rl Japan Spai nma or Greece Canada e N he Portu Germ D et N

Fig. 13. Time evolution of the speciﬁc turnkey cost and variation by EU country (based on data from [47,48]).

Another important technology issue is grid integration, with WTs more aesthetically attractive and integration of small WTs into large-scale penetration of onshore and offshore wind parks chal- several structures. lenging all parties involved and with system issues including power quality, voltage management, grid stability, grid adequacy, control 4. Economics of wind energy of emissions and efficiency reduction of other generating plants [33e35]. As a result, in order to confront future wind power grid Among the main trends dominating the market of wind energy integration, the main directions include design and operation of the during the years, one may note the size increase of contemporary power system with the introduction of demand side management WTs, the efficiency improvement and the long-term reduction of techniques and energy storage [36e38], grid infrastructure issues the specific investment cost per kW (turnkey cost) of installed wind meaning reinforcement and upgrade of networks, grid connection power capacity [47]. Concerning the latter, although starting from of wind power with grid codes issued, market operation with the a remarkable 3500€/kW during the mid-eighties, it has during the introduction of more flexible mechanisms and other issues such as last years stabilized in the order of 1200€/kW, i.e. between 1000 institutional [39]. €/kW and 1400€/kW [48], depending also on the area of study Finally, of special interest is as already implied, the industry of (Fig. 13a and b). small scale WTs [40e42], satisfying a range of applications [43e45] In this context, some rough numbers may also be given in terms (Fig. 12). Such applications may concern both on-grid and off-grid of investment cost breakdown, noting also the difference between concepts like building integration, mini wind farms and single onshore and offshore applications. More specifically, the turbine turbine installations for the first category, and wind-battery along component being critical in onshore projects (w930€/kW) with wind-based hybrid systems for the second [46]. Besides, the (Fig. 14a) drops to a typical 48% in offshore plants (Fig. 15a) while on interest lately exhibited may also be illustrated by the recent the other hand, foundation requirements increase by more than developments in the specific field, these including active pitch four times and grid connection in offshore is increased by more controls for high wind speeds, vibration isolators to dampen sound, than 150€/kW. Overall, the total specific investment cost of offshore advanced blade design, self-protection mechanisms for extreme applications is found to be higher by more than 40% for most of the winds, dual mode models (both on- and off-grid), software devel- plants in operation and may increase to even exceed 3000€/kW for opment, inverters fitted into the nacelle, attempts to make small installations that are under construction [49,50]. Besides, based on J.K. Kaldellis, D. Zafirakis / Renewable Energy 36 (2011) 1887e1901 1895

Fig. 14. Breakdown of the investment (based on data from [48]) and the maintenance and operation cost (based on data from [52]) of onshore wind parks. the experience of in operation offshore parks employment of more Spain, India, etc.) [60] led to the remarkable growth of wind energy turbines implies relatively lower turnkey costs (Fig. 15b). Any case generation (see also Fig. 17aec). given, M&O costs (Fig. 14b) including insurance, regular mainte- Finally, one should also emphasize on the employment oppor- nance, repairs, spare parts, administration, land rent and others tunities [61] offered by the expansion of the wind energy market at [51e53], are also considerable for wind power installations, a global level. Somewhat 100,000 plus 50,000 is the number of although the introduction of more efficient machines and the people employed directly and indirectly in the wind energy field of reduction of downtime hours constantly decrease the M&O Europe, while another 85,000 correspond to the 100 manufacturing requirements which are now in the order of 1.2e1.5c€/kWh. plants operating in the USA. These include employment posts in On the other hand however, the wind energy production cost is manufacturing companies, in promotion, utilities, engineering and found to be comparable with the respective of conventional fossil- R&D (direct employment) or employment in companies providing fueled generation methods [54], even without internalizing the services or producing components for WTs (indirect relation). Note externalities. As a result, clear advantage of wind power in the that according to rough estimations [62], among the leader coun- economic field as well becomes evident (Fig. 16), with estimations tries on the basis of the people employed per MW installed ratio concerning the near future electricity generation cost of onshore (Fig. 18), Denmark, Belgium and Finland employ more than 7 and offshore wind parks supporting values between 50€/MWh and persons while in terms of absolute numbers Germany currently 80€/MWh and between 75€/MWh and 120€/MWh respectively employs 38,000 people [63]. [55e57]. Following, State support, as already seen in the introduction 5. Environmental performance of wind energy section, led to the outbreak of California. In this context, of analogous importance for the remarkable growth of the wind energy Although suggesting an a-priori clean energy source, wind market has been the implementation of various support mecha- power also comes with certain environmental impacts [64] such as nisms [58] including price- and quantity-driven instruments such the visual [65] and the noise impact [66], the land use, the bird as feed-in-tariffs, investment and production tax incentives for the fatalities [67], the electromagnetic interference, the impacts on fish first and quota along with tradable green certificates and tendering and marine mammals and the embodied energy plus LC emissions systems for the second. At this point, one should underline the common in every power generation technology. Many of these effectiveness of most of these measures and especially the feed-in- impacts are nowadays perceived by many as “myths” [68,69] (see tariff mechanism [59], which since being adopted by the majority of also Fig. 19a), while others still lie on the subjectivity of oneself. leading countries worldwide (Germany, USA, China, Denmark, What is documented however [70e74] is that WTs require primary 1896 J.K. Kaldellis, D. Zafirakis / Renewable Energy 36 (2011) 1887e1901

Fig. 15. Typical investment cost breakdown and variation of offshore wind parks’ turnkey cost (based on data from [48]).

LC embodied energy amounts in the order of only 1e3MWh/kW comparison with conventional power plants (Fig. 20a). In fact, (that usually implies energy payback periods of months), with the according to estimations [78], realization of the high expectations stage of manufacturing being the most demanding (Fig. 19b). set by the EU for 2020 implies avoidance of externalities in the Furthermore, if also considering externalities [75e77], a clear amount of almost 40 billion €/year, with the distribution of cost advantage may be recorded for wind power installations in savings per country given in Fig. 20b.

Electricity Generation Production Cost: 2020 Estimation 500

400

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100 Cost of Electricity (Euros/MWh) 0 Biogas NG-GT Coal-PF Solar-PV Oil-Diesel NG-CCGT Solar-CSP Coal-IGCC Coal-CFBC Hydro-large Hydro-small Coal-PF-CCS Wind-onshore Wind-offshore Solid Biomass Oil-CC Turbine Oil-CC Nuclear Fission NG-CCGT CCS Coal-IGCC-CCS

Fig. 16. Electricity production cost estimation for various electricity power sources (Source: [55]). J.K. Kaldellis, D. Zaﬁrakis / Renewable Energy 36 (2011) 1887e1901 1897

Year of Entering the Feed-in-Tariff System by Country

Greece France Ireland Sweden Germany United States Denmark Canada

Italy India Portugal Austria

Spain China 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009

Time Evolution of the Wind Energy Production by Big Scale Producers Adopting the FIT System 55 50 Germany United States 45 India Spain 40 China Denmark 35 30 25 20 15 10

Wind Energy Production (TWh) 5 0 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 Year

Time Evolution of the Wind Energy Production by Small Scale Producers Adopting the FIT System 7 Italy Portugal 6 France Greece Sweden Austria 5 Ireland Canada

1 Wind Energy Production (TWh) 0 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 Year

Fig. 17. The feed-in-tariff effect for representative big and small scale wind energy producers (based on data from [14,60]).

Besides that, environmental performance of wind energy NIMBY attitudes [81e83], especially since availability of good sites perceived by the majority of people (over 70% in favor) [79,80] and is becoming increasingly rare. transformed in to widespread social support (only solar energy seems to be more socially accepted) further boosts wind energy 6. Wind energy prospects and R&D developments (Fig. 21). On the other hand, one of the challenges that wind energy is faced with during the recent years is the Up till now, the policy framework of the EU was of critical paradox of increased social support being obscured by real-life importance for the promotion of RES and wind energy in particular. 1898 J.K. Kaldellis, D. Zaﬁrakis / Renewable Energy 36 (2011) 1887e1901

Direct Employment in Wind Energy Companies in Europan Countries (2006-2007) 8

(Employees/MW) 2

a k e y ry al in K ri a nd ds g a en U st ium ece Italy n u d lg ranc e ng a oland rt Sp Au e ulgaria nmar F u Irela B e Finland erman Gr P Swe B D G H Po h Republic Netherl Chec

Fig. 18. Employment opportunities in the wind energy sector by EU country (based on data from [11,62]).

In this context, new targets set call for 20% coverage of the ﬁnal 681TWh of electricity and increasing the electricity demand energy consumption by RES by 2020, while in terms of electricity coverage from 4.1% in 2008 to 16.7% in 2020. consumption, wind energy is expected to contribute by a 14%e17%. In fact, two scenarios have been elaborated on the basis of the 2020 Moreover, according to long-term plans [84], 400 GW (250 GW target [84], i.e: onshore and 150 GW offshore, see also Fig. 22b) of wind power in the EU and 20% of the USA electricity demand covered by wind by 1. The “baseline” scenario that assumes a total installed wind 2030 [85], along with China requesting 150 GW installed by 2020 power capacity of 230 GW (Fig. 22a), producing 580TWh of [86], set the scenery of wind power prospects and challenge the electricity and increasing the electricity demand coverage by target of 1000 GW globally by 2030. In this context one should also wind from 4.1% in 2008 to 14.2% in 2020. note that: 2. The “high” scenario where the total installed wind power capacity is assumed to reach 265 GW by 2020, producing In India, existence of a domestic industry and 65e70 GW of assessed wind potential along with 10% of RES capacity and e Causes of Bird Fatalities per 10,000 Fatalities 4 5% of RES energy shares by 2012 are the main drivers of 6000 wind energy with estimations calling for 2 GW/year in the following period. 5000

4000

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1000 <1 0 Cats Other Vehicles Windows Building / Lines Pesticides Towers High Tension Wind Turbines Communication

Energy Use on a Life Cycle Basis for a 600 kW W/T 4

1 Scrapping, recovered

Gross Energy Use (TJ) Use Gross Energy energy 0 Manufacture Installation of O&M (20y) Total Scrapping, Total of Turbine turbine excluding energy use including scrapping scrapping -1

Fig. 19. Insight on the environmental impacts of wind energy; bird fatalities and life Fig. 20. Insight on the environmental beneﬁts of wind energy; life cycle greenhouse cycle energy requirements (based on data from [69,72]). gas emissions (based on data from [77]) and avoidance of external costs (Source: [78]). J.K. Kaldellis, D. Zaﬁrakis / Renewable Energy 36 (2011) 1887e1901 1899

Social Acceptance of Wind Energy in Comparison B Development of innovative logistics (Cross industrial with Other Technologies programmes) 100% Deeper waters and larger turbines for offshore B Development and industrialization of support structures for 80% sea installations, both ﬁxed and ﬂoating (Structure concepts 60% to be developed and tested at different depths and under different conditions) Don’t Know 40% Opposed Achieve grid integration for even greater wind energy Balanced Views penetration 20% In favour B Introduction of large-scale energy storage systems and high voltage alternative and direct current (HVAC-HVDC) inter- 0% connections (Offshore farms connected with more than one Oil Gas Coal grid, long distance HVDC, R&D of energy storage systems) Wind Solar Ocean Energy Energy Energy Nuclear Energy

Biomass Resource assessment and spatial planning

Hydropower B More sophisticated assessment of wind resources (High quality measurements and databases for wind data as well Fig. 21. Social acceptance of various electrical power technologies (Source: [80]). as short-term wind speed forecasting with the use of neural networks) Wind potential for onshore wind energy capacity in Brazil has B Spatial planning through social and environmental consider- been assessed at 143 GW (at 50 m high). ations (Development of planning tools and methodologies). At the end of 2008, Australia’s expanded the country RES target to 20% by 2020. South Africans turn to wind, since the bulk part of the 100TWh 7. Conclusions produced by RES up to 2025 is to be assigned to wind power. A review of the wind energy history undertaken in the current Finally, what is important to consider is that for the aforemen- work emphasizes on the main issues of global market facts, tech- tioned goals to be realized, R&D targets set must be put forward by nology, economics, environmental performance, prospects and the wind energy industry [87], with the main directions and actions R&D of wind power, providing some insight and presenting the fi to be taken including the following: highlights for each of the elds. From the review undertaken, the dynamics of wind power at the global energy scene during the last New wind turbines need to reduce their overall costs thirty years is illustrated, while according to the targets set, the B Large scale turbines of 10e20 MW going offshore (R&D perspective of exceeding 1 TW of wind power installations by 2030 programmes for prototypes already initiated) seems feasible, especially if considering the challenges introduced B Improved design and reliability of components (Testing by the need of each country to safeguard security of supply and facilities to assess efficiency and reliability of wind turbines) promote clean power technologies. Besides that, although the leading role of the EU throughout the period of wind energy development has been designated, the return of the USA and the tremendous growth of the wind energy industry in China are also reflected. On top of that, of special interest is also the gradual adoption of wind energy by several countries of the developing world, this clearly demonstrating both the catholic character of wind power and its ability to largely substitute fossil-fueled power generation in the years to come.

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• 2008 a Big Year for Wind Energy Development ((pespeciall y in the US and China )1

1Wiser, R and Bolinger, M. (2008). Annual Report on US Wind Power: Installation, Cost, and Performance Trends. US Department of Energy – Energy Efficiency and Renewable Energy [USDOE – EERE]. Logan, J. and Kaplan, S. M. (2008). Wind Power in the United States: Technology, Economic, and Policy Issues. Congressional Research Service [CRS]. http://www.mitenergyclub.org/assets/2009/3/6/Wind-online.pdf

• Highly Standardized Technical System: – 3-blade Upwind Horizontal-Axis with some variation in design of a ppyglanetary gearbox and induction , increasin gyygly in doubly-fed configuration, generator on a monopole tower • Progressive Increase in Size from 1970s to Today