Why Wind Energy?
Trevor M. Letcher, University of KwaZulu-Natal, Durban, South Africa Email: [email protected]
Abstract
The raison d’etre for the new book on wind energy engineering is discussed with a focus on our changing climate and the buildup of atmospheric carbon dioxide; hence the title of this introductory chapter—Why Wind Energy? The background to wind power is briefly mentioned.
The advantages of wind energy are discussed together with a look at the challenges facing the wind energy industry. The chapter ends with a brief look at the potential of wind energy as one of the most important of the renewable forms of energy.
Keywords
Wind energy; climate change; wind turbine technology; advantages of wind energy; challenges facing the wind turbine industry
1.1 Introduction
Wind Energy Engineering: A Handbook for Onshore and Offshore Wind Turbines is aimed at giving an overview and an insight into most aspects of wind energy. The industry is rapidly reaching a mature stage and it was felt that the time had come to take stock of the wide-ranging topics linked to the generation of electricity from wind. These topics include: an historical background; the reasons for the interest in wind energy; the fundamental science behind the industry; engineering aspects of building wind turbines, generating electricity, and coupling to the grid, environmental issues; economics; and the future prospects of the industry. Having all these disparate topics in one volume of 26 chapters gives the reader a chance to get know the subject and for the specialist to delve deeper. The latter will be rewarded with copious references to the latest work for further study. This book is an outcome of an earlier book we published, entitled Future Energy: Improved, Sustainable and Clean Options for Our Planet, 2nd edition (Elsevier, 2014), where only one out of thirty one chapters was devoted to wind energy.
1.2 Climate Change
Today with the specter of global warming and climate change looming over us, there is a need for the energy industry to find energy sources free of carbon dioxide pollution. Energy-related carbon dioxide (CO2) emissions contribute the majority of global greenhouse gas (GHG) emissions (66%) [1]; these include: electricity production, transport in all its forms, cement making and industry, to mention a few. The fight against climate change must become an important feature in energy policy-making, but the implications are daunting. The emission goals pledged by countries under the United Nations Framework Convention on Climate Change (UNFCCC) are laudable but it is still not enough to reach the level of keeping global warming to just 2°C above the preindustrial level by 2035. This temperature rise was first mooted in 1996 by the environment ministers of the European Council who declared that “global average temperatures should not exceed 2 degrees above the pre-industrial level.” It took until 2010, when the Cancun Agreement was signed, before the 2°C was enshrined in an international climate policy agreement to “hold the increase in global average temperature below 2°C above preindustrial levels.”
The spotlight is on the renewable energy industry to find energy sources free of carbon dioxide pollution. The other options are to reduce our consumption of energy and consequently our standard of living or to capture CO2 and bury it in caverns or under the sea (capture and storage, CCS). For many reasons, including our natural reticence toward lowering our standard of living, the cost of CCS, the increasing rise in the population of the world, the aspirations of all to a life with available electricity, it is unlikely that these two options will prevail. To put the problem in perspective, the world energy production (this includes: transport, electricity, heating, and industrial) reached 570 EJ (13, 800 million tonnes of oil equivalent (Mtoe)) in 2014, up 1.5% from 2013 [2,3]. In spite of dire warnings there seems to be little international governmental control in reducing this. Fossil fuels still account for 81% of this production—0.4% lower than in 2013—in spite of rising oil (+2.1%), coal (+0.8%) and natural gas production (+0.6%). A small positive sign on the horizon was the fact that during 2014, the energy production by renewable forms of energy did grow significantly, albeit from a low base. For example, hydroelectricity production was up 2.5% and accounted for 2.4% of global energy production, while wind and solar photovoltaics continued their rapid growth (+11% and +35%, respectively), but accounted for around only 1% of global energy production. In 2014 nonfossil sources, biofuels, and waste accounted for 10.2% of world energy production. Nuclear energy contributed 4.7% to the global energy production [3].
In this book we will focus our attention on electricity generation from wind energy. In Future Energy [1] we reported that the production of electricity worldwide was responsible for 26% of the global GHGs (mainly CO2 and CH4). Fossil fuel was responsible for producing 65% of global electricity (coal 38%, gas 22%, and oil 5%) (see Table 1.1) [4]. Wind and solar energy are at the forefront of the drive to significantly reduce the GHGs to meet the 2°C limit. This is largely because we know that if we can replace fossil fuel with wind and solar energy for generated electricity, we can significantly reduce CO2 emissions. At the moment wind turbines (433 GW in 2015) [5] have a greater installed capacity, worldwide, than do solar photovoltaics (242 GW in 2016) [6], but this is still a mere drop in the ocean. Wind and solar energy produce only 4% of the global supply of electricity [4]. There is much work to be done. Unfortunately, coal, the worst of the fossil fuel polluters, is still the main energy source for generating electricity. The chief culprits are China, the United States, and Australia; coal produces 72% of China’s electricity (total electricity is 5145 TW h) and 38% of the USA’s electricity (total electricity is 4255 TW h). Australia is the largest exporter of coal (metallurgical and thermal) in the world (35%) and in 2010–11 exported 283 Mt of coal with more than half going to Japan and China. It was forecast that this figure would increase by over 70% to 486 Mt in 2016–17 [7]. This does fly in the face of the Australian Federal Government’s renewable energy target of producing 33 TW h of electricity from renewable sources by 2020 [8,9].
Table 1.1
Total World Electricity Production in 2014 [4]
| Energy Source | World/% | Euro 27/% | North America/% | Asia/% |
| Coal | 38 | 26 | 33 | 59 |
| Natural gas | 22 | 15 | 28 | 13 |
| Hydroelectric | 17 | 11 | 13 | 15 |
| Nuclear | 11 | 27 | 17 | 4 |
| Oil | 5 | 2 | 2 | 4 |
| Biomass, solar, tides | 4 | 9 | 2 | 3 |
| Wind | 4 | 9 | 4 | 2 |
| Total energy/TW h | 22, 433 | 3062 | 5211 | 9372 |
| Average power/GW | 2559 | 350 | 594 | 1069 |
With well-developed wind and other renewable energy industries, we will not need to consider fracking, exploiting tar sands for oil and gas, or any other environmentally unfriendly fossil fuel mining; we should be working toward a situation where our huge fossil fuel reserves in all its forms are left in the ground. In reality, this will only come about when wind energy and other renewable forms of energy become cheaper and more convenient to use than fossil fuel. With mass production and bigger and more efficient wind turbines, this might well come about in the next decade.
1.3 Background
The extraction of kinetic energy from wind and its conversion to useful types of energy is a process which has been used for centuries. It is believed that the first windmills were invented 2000 years ago by the Persians and also by the Chinese and were used to grind corn and also to lift water (see Chapter 8: Wind Turbine Technologies). Later the Dutch would develop windmills to drain their land in the 14th century and, by the 19th century, millions of small windmills were installed in the United States and throughout the world for pumping water (from boreholes) and for stock and farm home water needs. The 19th century also saw the development of small wind machines (0.2–3 kW producing 32 V direct current) in rural areas in America to operate appliances. These early developments came to an end when the 1936 Rural Electrification Administration was created and grid electricity was supplied to most rural communities. The generation of grid electricity, using wind turbines, has its origins in the United States in the 1970s. Its development was initiated by the need to replace energy derived from fossil fuels with renewable forms of energy. Of all the renewable forms of energy (wind, solar, geothermal, and hydroelectric), wind and solar have shown very positive growth. Over the past 11 years wind energy capacity has increased from 48 to 433 GW; solar PV from 2.6 to 242 GW; hydro from 715 to 1000 GW; and geothermal from 8.9 to 12 GW [10,11]. These figures reflect the maximum possible power available and not what was actually delivered. For example, the electricity obtained from hydroplants in 2014 was 3769 TW h which, when averaged over a year, is equivalent to 430 GW power.
Wind energy is really a secondary level form of energy, reliant on the Sun’s uneven heating of the Earth’s surface, thus creating temperature differentials which create density and pressure differences in the air. The disparity in heating is often a result of the different heat capacities of the material (e.g., soil, water) being heated by the Sun. This is seen in the daily land and sea breezes in every coastal region. The different reflective nature of the rocks, soil and vegetation, snow, and water also plays a part. The direction of the wind is partly determined by the rotation of the Earth (trade winds) and the topography of the land with winds channeled between mountains and hills with valleys acting as conduits. Taking these issues into account, the tops of hills and mountains, gaps in mountain ranges and coastal areas are often the best places to harness onshore wind power (see Chapter 2: Wind Power Fundamentals and Chapter 3: Estimation of Wind Energy Potential and Prediction of Wind Power).
The extraction of wind energy by turbine blades is based on the same principle that gives aeroplane wings their lift. The wind causes a pocket of low-pressure air on the downside of the blade. This causes the blade to move toward the low pressure causing the rotor to turn. This is known as the lift. The force of this lift is much stronger than the force of the wind against the frontside of the blade. This is called the drag. A combination of the lift and drag causes the rotor to spin. This turns the generator and makes electricity. The power generated by a wind turbine is proportional to the cube of the wind velocity (P=av3, where P is power; a is a constant; and v is the wind velocity). Also the power generated is proportional to the area swept out by the blades making the power a function of the square of blade length (P=br2, where b is a constant and r is the length of the blade); so the bigger the blade the more power can be extracted—hence the drive to make larger and larger wind turbines (see Chapters 2, 3 and Chapters 8–11). Another issue with the placing of wind farms is that the wind offshore is stronger and more constant (daily with land and sea breezes) than it is onshore. Furthermore, most cities are situated in coastal regions and this could mean a reduction in electricity transmission costs if wind farms are situated offshore and near the customer base. These issues make it very likely that the future of wind energy lies in offshore wind farms, in spite of the fact that offshore wind farms cost more to establish than do onshore wind farms.
The rapid development of wind turbine technology has been due to the ingenuity of skillful engineers and material scientists. The first serious wind turbines developed for electricity production in the 1970s were rated at about 500 kW; today 8 and 10 MW turbines are being erected with plans to design 20 MW turbines. A typical, modern 3 MW wind turbine can produce enough electricity to power 1000 American homes. The largest wind turbine today is the American designed SeaTitan rated at 10 MW with a rotor diameter of 190 m. One of the reasons for the high structure is that the winds are more stable and faster the higher the turbine is from the ground or the sea. The offshore turbines tend to be larger than the onshore turbines. The limit to the size of wind turbines being manufactured and commissioned is at present determined by the problems in transporting the large blades and pillar components, the mechanic strength of the glass fiber blades, and the size of the cranes required to erect the turbines and cost. A solution to some of these problems is to build the blades and pillars offshore (see Chapters 8–16). A similar situation exists for oil rigs.
In spite of wind energy producing only 4% to the world’s electricity, some countries have embraced this technology more than others. In the European Union wind energy contributes 9% of the electricity production, while in the North America this figure is only 4% (see Table 1.1). The application of wind energy in producing electricity is fast becoming a major contribution to the energy mix of many countries in Europe. In Denmark, e.g., wind turbines contribute 40% of all electrical production from its 5 GW installed turbine capacity [12]. It was reported that in Portugal, for 4 days in 2016, all the electricity used was from renewable sources and of this 22% came from wind energy [13] (see Chapter 26: Growth Trends and the Future of Wind Energy).
The global capacity of wind energy is about 700 TW h or 433 GW. The leaders in the world are the United States 182 TW h, China 148 TW h, and Germany 58 TW h [4] (see Chapter 5: The Future of Wind Energy Development in China and Chapter 6: Wind Power in the German System-Research and Development for the Transition Toward a Sustainable Energy Future). If the current rate of growth continues, wind energy could supply a third of all global energy by 2050.
1.4 Advantages of Wind Energy
There are many advantages to using wind turbines to generate electricity and these advantages have been the driving force behind their rapid development.
• Provision for a clean source of energy. The almost pollution free nature of wind energy is one of the compelling reasons for its development. It delivers electricity without producing carbon dioxide. The relatively small amount of GHG emissions associated with wind turbines is produced in the manufacture and transport of the turbines and blades. It is also free of particulates which are a major problem with coal-fired power stations. Particulates have been blamed for the rise of asthma and possibly Alzheimer’s disease in our society, so any reduction in these fine particles floating in the atmosphere is a major health advantage. Another atmospheric pollutant that comes with coal- or oil-fired power stations is sulfur dioxide, formed from the burning of sulfur impurities. It is this SO2 that is largely responsible for acid rain and also climate change; replacing fossil fuel power stations with wind energy and other renewable energy can rid the planet of this dangerous pollutant.
It is estimated that a 1 MW wind turbine offsets 2360 t (2600 US tonnes) of CO2 [14].
• Sustainability. Whenever the Sun shines and the wind blows, energy can be harnessed and sent to the grid. This makes wind a sustainable source of energy and another good reason to invest in wind farms. Furthermore with the advent of climate change and global warming (the air molecules are moving faster), there is more energy in the atmosphere and we can expect stronger winds in the future.
• Location. Wind turbines can be erected almost anywhere, e.g., on existing farms. Very often good windy sites are not in competition with urban development or other land usage; such areas include the tops of mountains or in gullies between hills (see Chapter 4: Global Potential for Wind Generated Electricity and Chapter 23: Wind turbines and Landscape).
• Compatibility with other land uses. Wind turbines can be erected on pastureland with little disturbance to the animals and the general farming activities. Other areas such as near landfills sites, the sides of motorways and major roads, where urban development is unlikely to take place, are ideal locations to consider for wind farms.
• Reduction of costly transport costs of electricity from far-away power stations. Transporting alternating current electricity great distances is expensive because of the cost of the cables and pylons and also because of the loss of power due to the electrical resistance of the cables.
• National security. The wind is a free source of energy. Being independent of foreign sources of fuel (e.g., fossil fuel and indeed of electricity) is a great advantage. It means no price hikes over which we have no control and no embargoes on importing fuel or even electricity from foreign countries.
• Conservation of water. Traditional power stations using coal, oil, gas, or nuclear fuel all use large volumes of water [15]. Wind farms use no water. In September 2012 Civil Society Institute of the United States published a report, “The Hidden Costs of Electricity: Comparing the Hidden Costs of Power Generation Fuels.” Their conclusions were that: nuclear uses 2660–4180 L (MW h)−1 (700–1100 gal (MW h)−1) in closed-loop systems; coal uses 1750–2280 L (MW h)−1 (500–600 gal (MW h)−1) in closed loop; biomass uses 152, 000–380, 000 L (MW h)−1 (40, 000–100, 000 gal (MW h)−1) for irrigating crops to burn; solar uses 855–1976 L (MW h)−1 (225–520 gal (MW h)−1) (washing photovoltaic panels); and wind uses 170–320 L (MW h)−1 (45–85 gal (MW h)−1).
• Reduction of destructive mining. The pumping of oil and gas (especially from ocean beds) and the mining of coal or uranium all have serious environmental impacts on the sea or land. Wind farms are relatively benign in this respect and farming and other activities can take place around the turbines as the real action is over a hundred meters above the ground or sea. See Ref. [16] for the environmental issues with coal mining in Australia.
• Short commissioning time. Wind farms can be commissioned over a relatively short time, and 2 or 3 years from conception to electricity production is not impossible. This can be compared to the many decades it takes to design, build, and commission a nuclear power station [16]. The fast rate of growth of the wind energy industry over the past 40 years could well be due to the speed at which wind farms can be commissioned.
• Cost effectiveness. Over the past decade, the cost of turbines has decreased significantly as a result of improved designs and mass production, so that today the cost of producing electricity from wind farms is now very competitive with fossil fuel-derived electricity [17]. Together, with the drop in investment costs, there has been a significant increase in the efficiency of turbines through increased hub height and larger rotor blade diameter. The overall cost of wind energy is linked to the energy used in turbine manufacture. Wind energy is capital intensive with 75% of the total cost of energy related to the upfront costs of manufacturing the turbines foundations, electrical equipment, and grid connections [18]. It has been estimated that the energy used in the production of a turbine is recouped in the 7 months of operation and when one considers that the lifespan of a turbine is over 30 years the energy and financial gain is significant (see Chapter 21: Life Cycle Assessment: Metaanalysis of Cumulative Energy Demand for Wind Energy Technologies) [19].
• Creation of jobs and local resources. The wind turbine industry is a rapidly growing industry and employs thousands of workers in the manufacture processes, transport of turbines, erection of turbines, and in servicing working turbines. Wind Energy projects can be of great help in developing local resources, labor, capital, and even materials. In 2016 the US Energy Department analyzed the future of wind energy and quantified the environmental, social, and economic benefits coming from the wind industry. The industry in the United States currently supports more than 50, 000 jobs in services such as manufacturing, installation, and maintenance. Wind energy has become part of the country’s clean energy mix. It suggested that by 2050, more than 600, 000 wind-related jobs could be supported by the industry [20].
• Source of income for farmers, ranchers and foresters and grid operators. Land for onshore wind farms is leased to electricity supply companies, making a tidy profit for the landowners who can carry on the normal activity on the land with little interference from the turbines. Lease times between 25 and 50 years are common. The UK Government has suggested that for a 2.5 MW turbine, costing £3.3×106, the payback time was between 1 and 5 years, allowing plenty of time for a good return on the investment [21,22].
• Rapid instigation of power. National grids supply a steady level of electricity (the base load) to meet the needs of a country. If for some reason the supply of electricity needs to be suddenly increased that is not always possible as it can take days to start up a new power station. If the wind is blowing or if the wind energy has been stored then the supply can take just minutes to feed into the national grid.
• Diversification of power supply. With our total reliance on electricity it is well worth diversifying our energy sources so that we are not reliant on one type of energy, be it fossil fuel (which is at the mercy of foreign governments which can raise prices suddenly as was done in the 1970s), nuclear (again we are at the mercy of countries supplying uranium), or solar (the Sun does not always shine).
• Stability of cost of electricity. Once the wind farm is in place the cost of the electricity to customers should be stable. It is not a function of the price of imported fuels [22].
• International cooperation. It has been found that in many instances there is a clear relationship between a manufacturer’s success in its home country market and its eventual success in the global wind power market. Lewis and Wiser recently wrote, “Government policies that support a sizable, stable market for wind power, in conjunction with policies that specifically provide incentives for wind power technology to be manufactured locally, are most likely to result in the establishment of an internationally competitive wind industry” [23]. This comment written 10 years ago could well have been written today, and illustrates the importance and success of international cooperation.
1.5 Challenges Facing the Wind Turbine Industry
There are of course a number of challenges associated with harnessing the power of the wind.
• The intermittency of wind. Wind is unpredictable and this is perhaps the most important of all the problems associated with electricity production from wind farms. The wind may not be blowing when the electricity from a wind farm is required. Furthermore, when the wind is blowing and electricity is being produced, it is possible that the energy is not required. The solution is to store the electricity when it is not required and using the stored electricity in times of need. This can be done in a number of ways: batteries, pumped water storage, pumped air or methane into caverns, and even driving trains up hills (see Chapter 4: Global Potential for Wind Generated Electricity and Chapter 18: Energy and Carbon Intensities of Stored Wind Energy) [24].
• Good sites are often in remote locations. The best windy sites are often in hilly, mountainous regions away from urban areas. This does mean that the electricity produced onshore has to be transported along expensive high-voltage cables to reach customers.
• Noise pollution. The noise from a rotating wind turbine falls off exponentially with distance from the tower, and at 500 m the sound level is less than 35 dB which is not very much when normal conversation is rated at 60 dB (see Chapter 23: Wind Turbines and Landscape) [25].
• Aesthetics. While some people deplore the sight of wind turbines, others look upon them as pleasing and useful structures. We have over the past century got use to massive pylons marching across our countryside, carrying high-voltage lines. Surely wind turbines are better looking than that! There have been thoughts of painting wind turbines to fit in with the landscape (see Chapter 23: Wind Turbines and Landscape).
• Turbine blades can damage wildlife. There is much evidence that birds and bats are being killed by the turning blades of wind turbines. However the impact on these populations is negligible compared to the large number of bird deaths caused by household cats, car windscreens, sparrow hawks, etc.; it is reported that collisions with turbine blades results in 33, 000 bird deaths, while cats are responsible for 100–200 million each year in the United States. It has been reported that the modern very large bladed slow-turning turbines are responsible for far fewer bird deaths that the faster turning turbines (see Chapter 23: Wind Turbines and Landscape) [26,27].
• Safety. The major safety hazard associated with turbines, once they are in place, is the possibility of a blade coming adrift, which could cause serious harm to people or animals nearby. Furthermore a buckled blade could cause a collapse of the tower and that too could cause a serious damage. Wind turbines should be erected away from human habitation (see Chapter 22: Environmental and Structural Safety Issues Related to Wind Energy).
• Frequency of light and shadows. It has been reported that the frequency and strobe effect of turning blades could have an effect on the human brain. Wind turbines produce a shadow flicker by the interruption of sunlight by the turbine blades. Research work has shown that this flicker can cause epilepsy in certain patients [28]. It was found that the proportion of patients affected by viewing wind turbines, expressed as distance in multiples of the hub height of the turbine, showed that seizure risk does not decrease significantly until the distance exceeds 100 times the hub height. The results show that the flash frequency is the critical factor and should be kept to a maximum of 3 per second, i.e., 60 revolutions per minute for a three-bladed turbine. Furthermore, on wind farms the shadows cast by one turbine on another should not be viewable by the public if the cumulative flash rate exceeds 3 per second. If possible, turbine blades should not be reflective [28]. Wind turbines are designed to operate over a given range of wind speeds and this is usually between 4 and 15 m s−1 (between10 and 40 miles per hour). The speed of the rotating blade can be controlled and slow-rotating turbines could make turbines less of a problem for epilepsy sufferers and for other problems such as the danger to birds and bats.
• New and unfamiliar technology. Wind turbines and their accompanying generators can be considered as new technology and are often unfamiliar to most general engineers. This can be a problem if a turbine malfunctions in a rural area. The infrastructure and training of staff to support and maintain turbines must accompany commissioning of new turbines. However, it is reported that wind turbines require less maintenance that do many other electricity producing equipment [29].
• Shortage of the rare earth element, neodymium, needed to manufacture turbine magnets. Modern turbines require special permanent magnets and these are made from an alloy that contain the rare earth element neodymium (Nd). A 3 MW turbine needs a 2.7 kg magnet made from neodymium, iron, and boron (NdFeB). These are permanent magnets and are very much stronger than iron magnets. It is necessary to have such strong magnets in order to generate electricity at the slow speeds that wind turbines operate at. It is a case of “the stronger the magnet the more the electrons move.” The supply of neodymium and other rare earths has been dominated by China but this is slowly changing with the reopening mines in the United States (see Chapter 24: Global Rare Earth Supply, Life Cycle Assessment, and Wind Energy).
• Initial cost. The initial cost of setting up a wind farm is perhaps the most serious drawback. It is for this reason that many governments throughout the world still offer subsidies. This is however outweighed by the rewards over the lifetime of the turbine, both financial and environmental (see Chapter 25: Economics of Wind Power Generation) [30].
In the United States, most of the commercial-scale turbines installed today are 2 MW in size and cost roughly $3–4 million [31].
1.6 The Potential of Wind Energy Worldwide
The potential for wind energy is enormous, especially in developing countries. This is particularly true in rural communities which are not yet linked to grid electricity. For these regions it is an economically viable alternative to diesel engines and even coal-fired power stations [32]. Developing countries with their often obsolete energy supply structures should be investing in this new and proven energy industry, which is fast reaching market maturity. In many cases it would save on buying fuel from other countries and instead that could enjoy the luxury of free fuel in the form of wind (see Chapter 4: Global Potential for Wind Generated Electricity). One issue we must not overlook and that is the linking of wind turbine farms and national grids. This has been part of the success story of the wind industry (see Chapter 17: Physical Modeling of Offshore Wind Turbine Model for Prediction of Prototype Response and Chapter 19: Small Scale Wind Turbines). The next major advancement could well be more effective energy storage for times when the wind is blowing and electricity is not required (see Chapter 18: Energy and Carbon Intensities of Stored Wind Energy).
Even in developed and industrialized countries wind is becoming a major player (see Chapter 5: The Future of Wind Energy Development in China, Chapter 6: Wind Power in the German System-Research and Development for the Transition Toward a Sustainable Energy Future, and Chapter 26: Growth Trends and the Future of Wind Energy). To put it in perspective, on Sunday about 2 p.m. on 15 May over 95% of Germany’s electricity was supplied by renewable energy (36% by wind, 45.2% by solar energy, and the rest by hydro and biomass) [33]. That could not have been envisaged 40 years ago. A Norwegian island is showing the way for rural communities. It has a population of 4000 and is totally dependent on wind energy for all its electricity. The 21 wind turbines, most of which are part-owned by the islanders, supply the island with almost 30×106 kW h of energy and on top of that 80×106 kW h is sold to the national grid. In Denmark 39% of the electricity produced is from wind power. This stems from a decision in 1985 to abandon nuclear power and invest in renewable energy. This initiated the beginning of the Danish domination of turbine manufacturing in Europe [34]. For many developed countries, the incentive to invest heavily in wind energy has been dictated by the need to reduce CO2 emissions. However, today, with the competitive price of wind energy [17] (see Chapter 25: Economics of Wind Power Generation) and the rising cost of fossil fuel exploration and the political drive to close coal-fired power stations, the future looks very bright for the wind turbine industry.