A second prototype will go up this month at a site near Brunsbüttel to test performance under the very different wind conditions near the North Sea coast compared with those at the Baltic Coast. "The winds on the Baltic coast are often overestimated," says Volker König from Nordex. "You have to move right to the north east of Mecklenburg-Vorpommern and the island of Rügen before you find winds comparable with those in Schleswig-Holstein. "
The development of the Nordex 800 kW, a stall controlled turbine, was carried out entirely in Germany with support from the Mecklenburg-Vorpommern government. The state contributed 40% of the DEM 4.9 million development costs. The second prototype has been granted subsidy under the most recent round of the European Union's Thermie programme for support of energy technology development. Thermie will provide 40% of the costs of installing the machine and monitoring its performance, expected to reach around DEM 2.6 million.
König has no regrets over the decision to build an 800 kW machine rather than take the leap into the 1 MW class. He points out that costs do not rise in proportion to increasing the dimensions of a wind turbine, but often much faster. He adds that manufacturers of machines in the 1 MW plus class will find it hard to cut the cost of electricity generation to match that of the 500-800 kW wind turbines. Just the cost of hiring a crane to install an 800 kW machine, at DEM 50,000, is ten times more than for a 250 kW, he says. The price of a gearbox for, say, a 1.2 MW machine costs twice as much as five gearboxes for a 250 kW turbine. König adds that while he can choose from around 50 manufacturers for the supply of a gearbox for his 800 kW, the choice shrinks dramatically for a gearbox for a 1 MW.
König also argues that utilities with weak grids are likely to be happier with the steadier output of an 800 kW machine, operating at 3000 full load hours a year, than with a 1 MW machine with only 2500 hours a year. He says, too, that he was determined to use the new 24 metre blade from LM Glasfiber of Denmark, tested since 1994. This blade would have been too small for a bigger turbine. Nordex has firm orders for five 800 kW turbines and these will be built at the Nordex works at Rerik. However, a total of at least 25 are expected to be in the ground by the end of the year and Nordex is continuing negotiations with several machine manufacturing companies to find a manufacturing partner, including holding talks with Klemens Gottwald Werke in Schwerin.