Despite the small size of the 12 turbine development, the use of 4-5 MW machines will make it economic, says Alexander Klemt of Prokon Nord Energiesysteme in Leer. The cost of the wind station, the first to be built in waters as deep as 30 metres, is estimated at EUR 125-140 million. Each turbine is expected to yield 20 million kWh annually.
Construction is scheduled for spring 2003 when Klemt hopes there will be a range of turbines in that size to choose from. He expects German Enercon to be the furthest ahead with a 4.5 MW turbine. Enron, however, is working on a 3.6 MW turbine, while two other German partnerships, Pfleiderer/Multibrid and Repower/Nordex, have 5 MW turbines under development.
Klemt expects state planning authorities to license the cable route in the 12 mile zone before the end of the year. Shortly afterwards a licence is expected from the BSH for the route from the 12 mile boundary to the wind station. Electricity will be fed into the E.on Netz high-voltage network at the Emden/Borsum transformer substation via a 115 kilometre, 110 kV AC cable. "Eon Netz will give the green light for connection of the pilot wind station to its network now that we have the construction license for the turbines," Klemt says.
Once in operation, the technical performance and environmental impact of the 12 turbines will be monitored for about three years. This will provide the basis for decisions on further development of the project to about 1000 MW, using another 196 turbines of the same size, according to Prokon Nord.
Klemt is confident that Eon Netz will be able to take the 1000 MW onto its grid. "The company has a route to the Ruhr region where only one side of the pylons is used. It should be relatively simple to increase transmission capacity," Klemt says. "While laying the cable to carry AC current for the pilot phase, we'll lay empty pipes for high voltage DC (HVDC) cable for the main project," Klemt says. He comments that ABB's much discussed HVDC Light cable system is "interesting but expensive," adding: "It's a module system for 80 MW units, but could be improved in the five years to when we need it. Siemens' similar development, known as HVDC Plus, could be an alternative," he notes.
Prokon Nord is a separate company to Prokon Energiesysteme of Itzehoe.