REpower Offshore turbines at Thornton Bank and alpha ventus achieve first class operational results

*The systems installed at the Thornton Bank wind farm achieve outstanding levels of power output and technical availability
*REpower turbines at the alpha ventus test site reach positive performance levels as well


Hamburg, June 15, 2010. Almost one year after final commissioning of the Thornton Bank wind farm in Belgium, REpower Systems AG (WKN 617703) is in a positive mood. The availability of the six REpower 5M turbines has been consistently above 97% over a period of six months, and with that – despite the adverse conditions in the open seas – at the level of onshore turbines. Since the turbines were officially commissioned, over 4,000 full load hours have been recorded per turbine.

The six turbines installed by REpower in the German alpha ventus test field have been delivering positive results in the first weeks and months of operation and are currently working excellently as well. Several of the turbines installed at this site have already completed their operational trials.


The initial phase of the Thornton Bank project with six REpower turbines was officially inaugurated at the end of June 2009 and, for the remainder of the year, achieved a technical availability rate of 94%. The wind farm is located 28 kilometers off the Belgian coast in waters between 12 m and 27 m deep, making it one of the first such wind farms to be located so far offshore. Of course, this makes service particularly challenging. REpower Chief Technology Officer (CTO) Matthias Schubert says: “We have deliberately prepared ourselves for these more difficult access conditions. Thanks to continuous improvement measures in service, we have managed to raise the technical availability for the current year to over 97% – a peak value that even many onshore systems cannot emulate.”

This was enabled through the ongoing optimization of the maintenance concept and the resulting reduction of downtime during inspections. Faults are immediately identified by a Permanent Monitoring System (PMS) and then quickly rectified by locally based service technicians from REpower Benelux. A team of specialists works in parallel to the service technicians to ensure that each individual fault type is permanently eliminated. As a result, 4,000 full load hours were achieved even in the first year of operation – a figure that would be impressive enough even for onshore sites. “This proves that we can expect much more wind offshore than onshore and, as a result, much higher power outputs,” adds Schubert.

REpower was also able to post positive output figures for the alpha ventus wind farm. As Schubert says: “Our systems there are running without any problems and have proved their worth at the test site. The experience that we have gained with more than two dozen turbines at coastal onshore and offshore locations since the setup of the first prototype in 2004 has proved extremely useful.” The design of the REpower offshore systems is also adapted to the special conditions associated with operation on the high seas. “Our offshore turbines are designed to be extremely maintenance-friendly so that all large system components such as the gearbox can, if necessary, be repaired on site – that is in the open sea far away from the coast – without the need for large pieces of equipment,” says Schubert.