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11ВЕТРОЭНЕРГЕТИКА
WIND ENERGY
Статья поступила в редакцию 17.04.11. Ред. рег. № 965 The article has entered in publishing office 17.04.11. Ed. reg. No. 965
УДК 504.05
ВОЗДЕЙСТВИЕ ВЕТРОВЫХ ЭЛЕКТРОСТАНЦИЙ НА ОКРУЖАЮЩУЮ СРЕДУ
С.М. Говорушко
Тихоокеанский институт географии ДВО РАН 690041 Владивосток, ул. Радио, д. 7 Тел./факс: 8(4232)311653, e-mail: [email protected]
Заключение совета рецензентов: 27.04.11 Заключение совета экспертов: 28.04.11 Принято к публикации: 30.04.11
Рассмотрены основные параметры ветра, дана краткая характеристика использования ветровой энергии в мире, описаны типы ветровых электростанций, показано воздействие ветроэнергетики на различные компоненты и параметры окружающей среды (отчуждение земель, животный мир, шумовое воздействие, визуальное воздействие, электро-, радио- и телевизионные помехи).
Ключевые слова: ветроэнергетический потенциал, ветряные фермы, окружающая среда, типы ветровых электростанций, турбины, ветряные мельницы, птицы.
WIND POWER STATIONS IMPACT ON THE ENVIRONMENT
S.M. Govorushko
Pacific Geographical Institute FEB RAS 7 Radio str., Vladivostok, 690041, Russia Tel./fax: 8(4232)311653, e-mail: [email protected]
Referred: 27.04.11 Expertise: 28.04.11 Accepted: 30.04.11
The basic paramaters of the wind are described, brief information about wind energy using in the world is given, the main types of wind farms are considered, impact of wind power stations on the different components and parameters of the environment (withdrawal of land, wildlife, noise and visual impact, radio and television interference) is discussed.
Keywords: energetic potential of wind, environment, wind farms, types of wind power plants, birds, wind mills, wind turbines.
Main characteristics of wind
Wind is a motion of air relative to the Earth surface. The initiation of the wind is related to the non-uniform heating of the Earth due to cloudiness, heat accumulation by water bodies, surface relief, and a number of other causes. Wind is closely related to atmospheric pressure; it is directed from areas of high pressure to areas of low pressure.
The wind direction is the direction from which it blows. In order to indicate a direction, eight basic bearings - north, north-east, east, etc. - and eight intermediate bearings between them are usually used. One can distinguish instantaneous and smooth direction and speed. Smoothed value is the average value over a period of time. Instantaneous value gives a direct measurement of the time, it can vary widely around the
smoothed values. For wind power engineering smoothed wind speed is important. The average near-surface wind speed is about 10 metres per second (36 kilometres per hour) [1]. Mean annual wind velocity in different areas of the world is shown on Fig. 1.
Every obstacle the wind encounters modifies the wind field. Flowing around the obstacle, the wind weakens before it but intensifies on its sides. Immediately behind the obstacle, a windless region forms where the wind speed decreases sharply. When the air flow goes through a narrow spot (approaching mountain ranges, straight between high islands, etc.), the wind intensifies to a considerable extent. This intensification occurs because the speed of the wind increases as a volume of air moves across a decreasing cross section [2].
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Use of wind energy
Wind energy is, at its core, the energy of the Sun converted into the kinetic energy of moving air masses. Wind energy was widely used even in ancient Egypt and the Middle East for driving mills and water-lifting devices. Over the period 1880-1930, about 6 million wind power plants (WPPs) in the United States were used for water pumping, operation of enterprises, and power generation [3]. Currently the use of windmills for grinding of grain practically stopped. There are such windmills in some places yet but they are only monuments of the epoch (Fig. 2).
The energetic potential of wind is quite high. For example, for five countries in the North Sea region (Germany, Great Britain, the Netherlands, Belgium, and Denmark), it exceeds the total volume of power consumption of these states [4].
Wind power stations convert wind energy into electric power. They consist of several wind turbines constructed in one locality. The great wind power stations can consist of 100 or more wind turbines. Sometimes, they are called wind farms. The world's first wind farm - consisting of 20 wind turbines rated at 30 kilowatts each - was installed on the shoulder of Crotched Mountain in southern New Hampshire in December 1980 [5].
Wind energy is used in more than 70 countries. The leaders in the generation and use of wind power are the United States, Spain, and China. At the end of 2008, wind power provided some 1.3% of global electricity consumed [6].
Рис. 2. Ветряная мельница в г. Алфорд, Великобритания. Фото: Tom Philo Fig. 2. Wind mill in Alford, Great Britain Photo credit: Tom Philo
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Ветроэнергетика
Types of wind power plants
According to the where they are placed, the following types of wind power plants can be identified: (1) ground (wind turbines are usually installed in the hills); (2) coastal, or onshore (a small distance from the sea coast); (3) offshore (constructed at sea, within 10-12 kilometres of shore); and (4) floating.
So far, ground wind power plants are the most common. The greatest of them (and of wind power plants on the whole) is the power plant in Roscoe, Texas (U.S.). It was put into operation on 1 October 2009, and includes 627 wind turbines. Total output is about 780 megawatts. The area of the power plant is approximately 400 square kilometres.
The largest onshore wind farm is Florida Power & Light's Horse Hollow Wind Energy Center, located in Taylor County, Texas. The Horse Hollow project operates 421 wind turbines and has a capacity of 735 megawatts [5]. A coastal wind power plant in Denmark is shown on Fig. 3.
Рис. 3. Прибрежная ветровая электростанция в Дании. Фото: В. Кантор, Гринпис Россия, 10 ноября 2000 г. Fig. 3. A coastal wind power plant in Denmark. Photo credit: V. Kantor, Greenpeace Russia, 10 November 2000
Рис. 4. Примером оффшорной электростанции является ветряная ферма Миддельгрюнден. Она обеспечивает 4% потребностей Копенгагена в электроэнергии. Ветер в этом районе не сильный, но постоянный, поэтому турбины производят электроэнергию 97% времени.
Фото: http://en.wikipedia.org/wiki/Middelgrunden Fig. 4. Middelgrunden is an example of an offshore wind farm. It delivers about 4% of the power for Copenhagen. While the wind at this location is not strong, it is very consistent, with the turbines generating substantial power over 97% of the time. Photo credit: http://en.wikipedia.org/wiki/Middelgrunden
The greatest offshore wind power plant is the Middelgrunden power plant (Denmark), with an installed capacity of 40 megawatts (Fig. 4). The plant was constructed in 2000 [7]. In late 2008, the total capacity of the offshore power plants in the world reached 1,471 megawatts. During 2008, 357 megawatts of offshore facilities were put into service. Great Britain is considered to have the greatest potential for creation of offshore wind power stations [4].
The first prototype of a floating wind turbine was constructed in December 2007. A wind turbine with a capacity of 80 kilowatts was installed on an offshore platform within 10.6 nautical miles of the south Italy coast, in an area with a depth of 108 metres. The world's first full-scale floating wind turbine, Hywind, is being assembled in the Amey Fjord near Stavanger, Norway [8].
Impact of wind power plants on the environment
The adverse effects of wind power engineering include the following: (1) condemnation of land; (2) influence on the animal world; (3) noise impact; (4) visual impact; and (5) electrical, radio, and television noises.
Wind turbines can not be too close to each other, because their capacities will be reduced due to wind flow interference. Therefore, their construction is related to considerable withdrawal of land. Wind power plants require approximately 0.1 square kilometre of free space per 1 megawatt of power rating. Accordingly, a power station with a capacity of 200 megawatts will require about 20 square kilometres of surface area [9].
The influence on the animal world is expressed as danger to birds, insects, and aquatic organisms. The impact on the ichthyofauna is most dangerous over the period of WPP construction: disturbances in their habitats result in fish migration and fish kill. During the operational period, the effects of noises and vibration are not great, while cessation of navigation and fishing between the turbine supports may even have positive consequences. The effect on marine mammals (dolphins, seals, whales) is also minor.
During the construction period, the bottom deposits and structure of turbulent currents change, which has an adverse effect, first of all, on benthic organisms. The extent of the impact depends on the substrate character; which is minimal in the case of bottom rock [4]. During the operational period, when electric power is transmitted through a submarine cable, an excess of admissible values of strengths of electric and magnetic fields may cause fright reactions among fish and bottom-dwelling organisms, and, in this case, the cable will be a barrier to fish migration [10].
As for the effect on birds, it is minimal according to data obtained by European ornithologists. Birds feel wind turbines at a distance of more than 1 kilometre and avoid them [4]. According to data obtained by B.K. Sovacool [11], 0.3-0.4 fatalities per gigawatt-hour of
International Scientific Journal for Alternative Energy and Ecology № 5 (97) 2011
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electricity have been recorded (Fig. 5), which correspond to about 70,000 birds a year for the territory of the United States.
Nevertheless, cases in France are known in which the deployment of wind power plants was not approved due to concerns over damage to birds [12]. In addition, some wind power stations discontinue operation during seasonal migration of birds [5].
Рис. 5. Гибель птиц при работе ветровых электростанций составляет 0,3-0,4 смерти на 1 гигаватт-час произведенной электроэнергии, что для территории США соответствует 70 тыс. птиц в год. Показаны птицы, пролетающие в непосредственной близости от турбин. Фото: B.K. Sovacool, Национальный университет Сингапура Fig. 5. Mortality of birds during wind farms working is 0.3-0.4 fatalities per gigawatt-hour of electricity, which correspond to about 70,000 birds a year for the territory of the United States.
The picture shows birds navigating around wind turbines. Photo credit: B.K. Sovacool, National University of Singapore
There are also data on the death of bats. A study in 2004 estimated that over 2,200 bats were killed by 63 onshore turbines in just 6 weeks at two sites in the eastern United States [13].
The noise impacts caused by wind turbines can be subdivided into mechanical and aerodynamic. The components responsible for the greatest noise are the generator; the swing actuator, which turns the top part of the wind power plant toward the wind; the gearbox; and the blades. Noise from some of these components is continuous, while that from the others occurs from time to time; however, noise is produced only when the turbine is operating. All in all, the noise of spinning turbines is relatively low as compared with that of other industrial sources.
Visual impacts also occur, but they are subjective. Many people believe that wind power stations improve the aesthetic qualities of the landscape; however, there are people who consider them to be unacceptable. In the United States, the Cape Wind Project in Massachusetts was delayed for years mainly because of aesthetic concerns [5].
Wind power stations are the source of radio and television interference. In particular, because of the reflection of radio waves in the ultra-short band (USB) and microwave range by the rotating blades of wind power plants, the normal operation of airlines' navigational instruments is disturbed and reception of television transmissions is complicated [14].
References
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2. Khromov S.P., Petrosyants M.A. Meteorology and climatology. Moscow: Moscow State University, 2001 (in Russian).
3. Howard A.D., Ramson J. Geology and environmental conservation. Leningrad: Nedra, 1982 (in Russian).
4. Kiseleva S.V., Nefedova L.V. Development of the wind-driven resources of the European shelf zones // Vestnik of Moscow University. Ser Geography. 2006. Vol. 6. P. 52-58 (in Russian).
5. http ://en.wikipedia.org/wiki/Wind_farm.
6. http://www.wwindea.org/home/images/stories/ pr_statistics2007_210208_red.pdf.
7. http ://en.wikipedia.org/wiki/W ind_power_in_ Denmark
8. http://en.wikipedia.org/wiki/Floating_wind_turbine.
9. http://en.wikipedia.org/wiki/Environmental_effects _of_wind_power.
10. Kadomskaya K., Kandakov S., Lavrov Yu. Submarine cable lines. Ecological aspects of designing // Bulletin of Electrical Engineering. 2006. Vol. 4 (40). P. 88-91.
11. Sovacool B. K. Contextualizing avian mortality: A preliminary appraisal of bird and bat fatalities from wind, fossil-fuel, and nuclear electricity // Energy Policy. 2009. Vol. 37, Is. 6. P. 2241-2248.
12. Thonnerieux Y. Eoliennes et oiseaux: Quelles consequences? // Courr. Nature. 2005. Vol. 218. P. 27-33 (in French).
13. Arnett E.B., Erickson W.P., Kerns J., Horn J. Relationships between Bats and Wind Turbines in Pennsylvania and West Virginia: An Assessment of Fatality Search Protocols, Patterns of Fatality, and Behavioral Interactions with Wind Turbines. 2005. Bat Conservation International.
http://batcon.org/wind/BWEC2004finalreport.pdf.
14. Engineering ecology and ecological management. Moscow: Logos, 2003 (in Russian).
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