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5Статья поступила в редакцию 06.10.2011. Ред. рег. № 1125
The article has entered in publishing office 06.10.11. Ed. reg. No. 1125
УДК 621.311.24
СОЛНЕЧНАЯ ЭНЕРГЕТИКА ИЛИ ВЕТРОЭНЕРГЕТИКА?
С. Ветцель, Е. Соломин
Компания ВЕРТИКАЛЬ-ЕВРОПА Ребенвег 16, 76756, Белльхайм, Германия Тел.: 0721 95588-14, факс: 95588-44, e-mail: vertical.europa@googlemail.com
Заключение совета рецензентов: 16.10.11 Заключение совета экспертов: 20.10.11 Принято к публикации: 25.10.11
Статья описывает сравнительные технические решения в ветровой и солнечной энергетике в Германском географическом климате, а также совместные исследования российских и германских Южно-Уральского государственного университета, ООО «ГРЦ-Вертикаль» и Компании ВЕРТИКАЛЬ-ЕВРОПА.
Ключевые слова: ветроэнергетика, солнечная энергетика, возобновляемые источники.
PHOTOVOLTAIC OR WIND SOLUTION?
S. Wetzel, E. Solomin
VERTICAL-EUROPA Company Rebenweg 16, 76756, Bellheim, Germany Tel. 0721 95588-14, fax: 95588-44, e-mail: vertical.europa@googlemail.com
Referred: 16.10.11 Expertise: 20.10.11 Accepted: 25.10.11
The article describes the comparison of wind and photovoltaic solutions in German geographical climate and mutual research of Russian and German scientists of South Ural State University, SRC-Vertical, Ltd. and VERTICAL-EUROPA COMPANY.
Keywords: wind power, solar power, renewable energy sources.
Photovoltaic solar power
At the end of 2007 Germany had an installed capacity of 3,830 MW. By the end of 2009, capacity had increased to 9,800 MW. The first 9 months of 2010 added about 5,400 MW in new solar capacity. In 2006, the European Commission anticipated that Germany may have installed around 4,500 MW by 2010. For 2009, the German government calculated that the PV industry provided 64,700 jobs in production, distribution and installation. Over 90% of solar PV installations are in grid-tied applications in Germany.
Completed in 2006, the 12 MW Solarpark Gut Erlasee photovoltaic system (Fig. 1), near Arnstein in Bavaria was at the time of construction, the world's largest PV system. The Waldpolenz Solar Park, which is the world's largest thin-film photovoltaic (PV) power system, became fully operational by the end of 2008. The power plant is a 40 MW solar power system using state-of-the-art thin film technology.
Рис. 1. Солнечный парк в г. Ерласи Fig. 1. Erlasee Solar Park
The new robotized manufacturing of solar modules was arranged in 2010 by Solar Fabric company in Freiburg (Fig. 2). Russian scientists from South Ural State University have visited the fabric and found that the quality is state of art and the pricing may compete with Chinese PV modules.
BS
International Scientific Journal for Alternative Energy and Ecology № 11 (103) 2011
© Scientific Technical Centre «TATA», 2011
С. Ветцель, Е. Соломин. Солнечная энергетика или ветроэнергетика?
Рис. 2. Роботизированное производство фотоэлектрических преобразователей в г. Фрайбург Fig. 2. Robotized solar production of PV modules in Freiburg
Wind power
Closely after the USA, Germany is the world's second largest user of wind power with an installed capacity of 23,903 MW by the end of 2008, ahead of Spain which had an installed capacity of 16,740 MW. 20,301 wind turbines are located in the German federal area and the country has plans to build more wind turbines (Fig. 3).
Рис. 3. Ветро-парк в г. Белльхайм Fig. 3. Wind farm in Bellheim
In 2009, 6.5% of Germany's total electricity consumption was satisfied by wind power. 867 wind power plants were constructed in 2008, and 952 more in 2009. At the end of 2009, Germany possessed 21,614 wind power plants. Their installed electricity production capacity was 25,777 MW. However this is a theoretical maximum, the actual output is vastly smaller.
Wind power currently produces about seven percent of Germany's total power and it is said that no other country has more technological know-how in this area. Wind power in Germany provides over 70,000 people with jobs and German wind energy systems are also exported. However, the economics of wind power in Germany are under close scrutiny and there are other issues which deserve consideration. These include the effect of wind turbines on the landscape, the effect on the bird population, and the effect on the tourist industry.
Following the 2011 Japanese nuclear accidents, Germany's federal government is working on a new plan for increasing energy efficiency and renewable energy commercialization, with a particular focus on offshore wind farms. Under the plan large wind turbines will be erected far away from the coastlines, where the wind blows more consistently than it does on land, and where the enormous turbines won't bother the inhabitants. The plan aims to decrease Germany's dependence on energy derived from coal and nuclear power plants.
Wind or Solar?
Comparing the wind and solar solutions is very hard because sometimes there is a wind and no sun, and vice versa. Combined solutions are quite expensive. That's why the try to compare the technical solutions in this article is more from practical than from theoretical point of view.
In general the wind solutions are well known. The advantages of Horizontal Axis Wind Turbines (HAWT) and Vertical Axis Wind Turbines (VAWT) are also described in literature. Thus we will take for the discussion the VAWT design just for an example. The power discussed is 3 kW of both wind and solar systems. PV module is equipped by sun tracking system.
There are lots of technical solutions in PV power. However there is a lack of inexpensive solutions in tracking the sun. We take a very simple, low cost, solar tracking system that has been shown to increase the output of the solar panels by as much as 60% in certain locations (Fig. 4).
Рис. 4. Фотоэлектрический преобразователь с системой слежения за солнцем Fig. 4. PV solar panel with tracking system
Sizing a system:
The system was calculated for German geographical conditions. Given 2.5 kVA of constant power consumption, and a power factor of 0.833, a system would need to provide 3 kilowatts of continuous power. This is 26,280 kW-hours per year.
If we assume that a PV solar system will provide 30% of the power or 7,884 KW Hours per year, and this system averages 6 hours of power per day, then the solar panel would be rated for about 3.6 kW. Leaving us to generate 18,369 kW-Hours per year, or 2.1 kW of average continuous power. The average cost of PV Watt on the market is $2. Thus 3 kW system will cost about $6,000 including the installation.
Международный научный журнал «Альтернативная энергетика и экология» № 11 (103) 2011 © Научно-технический центр «TATA», 2011
Солнечная энергетика
We assume that the turbine is located in a class 3 wind resource with an average of 160 Watts per square meter of swept area. The turbine size needs to be 15 square meters of swept area. Giving us a turbine of approximately 4.5 meters of height and a diameter of approximately 3.4 meters in diameter. This represents appr. 3 kW wind turbine. The cost of Watt is $2.5 for small wind turbines. Total cost of installed equipment is $7,500. Which is 1.25 times more than of PV installation.
Additional adjustments need to be made for tower height and capacity factors to provide safety margins.
Reference data:
- If there is no wind, there is no power;
- If there is only a little wind, there is no power;
- The wind power increases as the cube of the wind speed.
The equation for energy recovery from the wind is as follows: P = Cp^ApVi, where: P - power in watts (J/s); Cp - coefficient of performance; ^ - conversion efficiency; A - swept area (m2); p - density of air; V -wind speed (m/s), see table.
Мощность ветра Power in the wind
Wind speed Watts per, m2
m/s MPH
2 4.47 65
4 8.95 522
6 13.42 1763
8 17.90 4178
10 22.37 8160
12 26.84 14100
14 31.32 22391
16 35.79 33423
18 40.26 47589
Due to variability of wind, a Rayleigh distribution http://en.wikipedia.org/wiki/Rayleigh_distribution) is commonly used to calculate the wind power available (Fig. 5).
Additionally a Weibull distribution is frequently used.
The wind variation for a typical site is shown in the Weibull distribution shown below on Fig. 6. This curve shows an average wind speed of 7 m/s, and the shape of the curve is determined by a so called shape parameter of 2.
Computer model estimates the performance of the wind turbine (Fig. 7). The red line represents the predicted performance. The blue crosses are measured data points. This gives us a high level of confidence that we can estimate performance before we build hardware.
Рис. 5. Распределение Рэйлея Fig. 5. Rayleigh distribution
Рис. 6. Распределение Вейбулла Fig. 6. Weibull distribution
Рис. 7. Зависимость мощности от скорости ветра (вертикально-осевая ветроэнергоустановка с аэродинамическими регуляторами) Fig. 7. Power vs wind speed (VAWT with aerodynamic brakes)
The comparison gives the understanding that in Germany the PV is formally a bit better than Wind Turbines (WT). However the further analysis should include:
- The square for the installation of PV and WT;
- The appearance of wind and sun during the long period of time;
- The changing of the climate;
- The possibility of utilizing the silicon from PV panels;
- Life time of rotating parts of WT and PV;
- Technical aesthetics;
- Etc.
ГхГ*
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International Scientific Journal for Alternative Energy and Ecology № 11 (103) 2011
© Scientific Technical Centre «TATA», 2011
