Library from Germany
Lessons Learned: E.ON Netz GmbH, the largest grid operator in Germany, reports in its Wind Report 2005, that "Wind energy cannot replace conventional power stations to any significant extent...The more wind power capacity [on] the grid, the lower the percentage of traditional generation it can replace."
They call him the Don Quixote of the Uckermark. But unlike the Spanish literary figure, Hans-Joachim Mengel, a professor of political science at Berlin's Free University, isn't attacking imaginary "giants" in the Iberian hinterland. Rather, he is taking aim at the 400-foot windmills that blanket the German countryside. Mr. Mengel is not alone. Hundreds of citizens' groups have sprung up in Germany to battle "Verspargelung der Landschaft" - a new phrase in the German lexicon - meaning "the transformation of the German landscape into an asparagus field."
They introduced the world to "environmentally friendly" energy, but now some of Europe's "greenest" countries are under pressure to backtrack on wind farms as public anger grows over their impact on the countryside.
E.ON Netz manages the transmission grid in Schleswig-Holstein and Lower Saxony, about a third of Germany, hosting 6,250 MW of Germany's 14,250 MW installed wind-generating capacity at the end of 2003. This report focuses on the operational challenges and costs associated with the intensive use of wind power due to wind's variability and unpredictability.
This significant research by van den Berg explains why turbine noise as far away as 1900 meters (more than 6,000 feet) is resulting in complaints by residents particularly at night. The paper concludes that noise immission predictions are not accurate and result in the understating of turbine noise levels, particularly during nighttime conditions.
High annual growth rates over the past years resulted in an installed wind power capacity of 12 000 MW in Germany by the end of 2002 which generated about 17.3 MWh electricity, that is about 3.7 % of the German electricity consumption. This development was made possible by laws introducing feed-in tariffs for wind power generation. Due to the fluctuating nature of wind power generation the feed-in of growing amounts into the grid causes considerable challenges and costs for affected transmission system operators, who have to ensure a save grid operation, though basically good working wind power prediction tools exist. The owner of wind turbines do not have to deal with these problems since the Renewable Energy Act (EEG) ensures that their generated power is compensated for by fixed feed-in tariffs. In the long run, this is not a sustainable approach: Wind power needs to compete sooner or later fully with other power generating technologies at the market and wind turbine owners need to be able to sell a tradable product. After successfully supporting the development of the wind power technology, an approach is needed for including the owners of wind turbines in the task of realizing other ways than simply providing growing amounts of balancing power for wind power feed-in and gradually face them with the energy economic reality of integrating large amounts of wind power into the grid.
In conclusion, this study has shown that in many countries deregulation is having the expected effect of increased competition leading to price reduction. However, it is evident that pricing in markets depends not just on the status of deregulation, but also on the broader aspects of competition. Key factors here include the balance of supply and demand, generation fuel costs, the learning process that new markets go through, competition within different market segments and the costs of access to transmission and distribution networks. Deregulation is a long-term process that requires sustained attention.
A man walks near a demolished wind turbine in Goldenstedt, nortwestern Germany, Monday Oct. 28, 2002. The 70 meter (230 foot) high turbine fell during the heavy storms that hit Germany.
Wind energy, fed to the grid to save resources and reduce emissions, requires control power for balancing fluctuations; this causes fuel losses in thermal power stations and limits the degree of energy substitution. Facilities for energy storage are needed when greatly extending wind power use off-shore, at the same time generating secondary fuel for stationary and mobile applications.
This paper describes a case study in which low frequency noise (LFN) was suspected of causing disturbance in a semi-rural location close to an industrial estate. Previous attempts using conventional acoustic measurement techniques to resolve the case, or even prove the existence of a real acoustic problem, had proved unsuccessful. The study does not involve wind turbine noise directly, but the work done and resulting findings provide insight into identifying the problem of LFN and predicting annoyance.
Wind turbines convert the kinetic energy in moving air into rotational energy, which in turn is converted to electricity. Since wind speeds vary from month to month and second to second, the amount of electricity wind can make varies constantly. Sometimes a wind turbine will make no power at all. This variability does affect the value of the wind power……Editor’s Note: This ‘fact sheet’ is, on the whole, a comparatively fair report. The definitions provided for capacity factor, efficiency, reliability, dispatchability, and availability are useful. Its discussion of back-up generation, marginal emissions and Germany & Denmark, however, is disingenuous as is, to a lesser degree, its discussion of capacity factor and availability. IWA's comments (updated October '06) on these issues follow selected extracts from the 'fact sheet' below.
Siemens' wind turbine products and specifications are available by clicking on the web link.
REpower System's wind turbine products and specifications are available by clicking on the web link.
"Windmühlen-Wahn: Von umweltfreundlicher Energie zur subventionierten Landschaftszerstörung" ( The madness about wind turbines: from the dream of environmentally friendly energy to highly subsidized destruction of the countryside )