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.

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.

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.

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.