The legal action is being brought against transformer supplier Siemens and involved electricity companies by the Middelgrund Wind Turbine Co-operative, which owns ten of the 20 turbines (Windpower Monthly, April 2005). It is claiming DKK 17 million (EUR 2.3 million) in compensation. Transformers have failed on seven of its machines. The remaining turbines are owned by Energi E2 through its takeover of defendant electricity company Københavns Energi. The utility has also suffered seven failed transformers. The turbines were supplied by Bonus, since bought by Siemens.
The case has stood still for the past half year. The 8600 members of the Middelgrund co-operative, with assistance from Denmark's Technological Institute, discovered cracks in the transformers both before and after they failed. Prior to failure the cracks were only discernible with the aid of ultra-sound scanning. According to institute experts, the cracks occurred as a result of temperature changes. "There are clear indications that thermal tensions significantly contributed to the cracks that are the cause of the failures."
Neither the supplier of the grid connection, NKT, Siemens, nor the utilities acting as general contractors, SEAS and Københavns Energi, will accept the institute's conclusion. A ruling is thus required on the report before the tribunal can begin to apportion responsibility for the failures.
Arbitration in such a case normally takes a couple of years, but it appears this one could take longer. The ruling is not usually made public in respect of the commercial interests of the involved parties. That could become a two-edged sword in view of the attention the case has already attracted. Keeping the results secret would leave each of the involved companies under suspicion, whether they were absolved or not by the tribunal.