U.K. Court Invalidates Enercon Patent, But Is This The End Of The Story?

Written by Philip Totaro
on July 28, 2015 No Comments
Categories : New & Noteworthy

A decision by the High Court of Justice in the U.K. has dealt a blow to turbine manufacturer Enercon concerning its patent related to power ramp-down after the cut-out wind speed. Enercon sued Siemens, DONG Energy and A2SEA for patent infringement, claiming that those companies used, purchased and installed wind turbines using its patented technology.

Enercon first filed its patent in 1995 in Germany and has been commercially offering its so-called storm control technology on its own turbines for many years since.

In invalidating the Enercon patent, the U.K. court had an interesting interpretation of a paper from E.A. Bossanyi, published in 1982, that evaluates the performance of the Boeing-built MOD-2 wind turbine that was contracted by NASA and erected in 1980. Essentially, the Bossanyi paper contemplates a method for power ramp-down that is specially adapted to the variable speed, constant frequency (VSCF) MOD-2 wind turbine. Siemens relied upon expert testimony in arguing that this approach could be applied to variable speed, variable pitch (VSVP) machines being developed around the time of the Enercon patent filing. The U.K. court agreed.

Siemens also referenced a 1980 patent filing by Toshiba in its attempt to invalidate the Enercon patent. The Toshiba patent describes technology that ramps down after the "conventional" cut-out wind speed but does not ramp all the way down to null output power, cutting out in a full-speed, partial-load condition.

Open opposition
Interestingly, Vestas had previously filed an opposition against the European version of the Enercon patent in a time frame that would have allowed it to present new prior art. However, its opposition was rejected in November 2002, as it did not cite the Toshiba patent or the Bossanyi paper in its attempt to limit or invalidate the Enercon patent.

Nevertheless, a new opposition period against the Enercon patent filing was made possible as of January based upon an amendment to the Enercon patent triggered by the U.K. court matter. The prior art that references the precedent set in the U.K. will likely influence a decision by the European Patent Office (EPO) on the validity of the Enercon patent.

However, invalidity of the European patent is not for certain, and Enercon still has the opportunity to appeal the U.K. ruling. The EPO does not have to accept the same conclusion as the U.K. court, so it will be noteworthy if the EPO takes the same approach regarding the Bossanyi reference in its review of the amended Enercon patent.

Because Enercon is likely to appeal the U.K. ruling, the Siemens matter is far from over.

The European patent filing from Enercon serves as the parent to both the U.K. and the Spanish patent, which is the subject of the ongoing litigation with Gamesa. The precedent set in the U.K. is likely to have repercussions on the litigation in Spain if the U.K. court position on invalidity holds.

An invalidation of the European patent would likely negate the damage award against Gamesa in Spain, but there is potentially still room for Enercon to argue its position here, so the outcome is not guaranteed for anyone involved.

In the meantime, Gamesa should at least be able to leverage off the non-infringement arguments in its appeal in the Spanish court.

New precedent
The U.K. court potentially establishes another interesting precedent here, as there are certainly other patents held by companies in the wind industry that attempt to deal with component loading and fatigue, which could also potentially be argued as obvious in light of the U.K. court's interpretation of the technology developed for VSCF being applicable to VSVP-based turbines.

The U.K. court judge refers to the adjustment of the torque and pitch control ‘knobs’ as a means to control generator rotor revolutions per minute as an obvious method in light of the Bossanyi paper, but he also acknowledges other methods of implementing such technology.

‘â�¦it required no inventive activity at all for a skilled person given Bossanyi in 1995 to think seriously about how to implement the power ramp down proposal in VSVP turbines. They would consider how to put that into practice and, in terms of controls, it was obvious to think about ‘turning’ the electric torque ‘knob’ and the pitch control ‘knob.’ Reducing rotor speed while the wind speed increased as a way of reducing power accordingly is not the only way of putting Bossanyi into practice, but it is an obvious approach. Reducing the speed this way has an obvious advantage in terms of loading and fatigue.’

The implications of all these proceedings introduces some potentially substantial commercial risks into the project development process. Now that companies are willing to target the turbine original equipment manufacturers, project developers, and even the engineering, procurement and construction contractors for patent infringement liability, proactive companies are already arming themselves with information to ensure they can proceed smoothly.

Philip Totaro is CEO of Totaro & Associates, a market research and strategy consultancy. He can be reached at ptotaro@totaro-associates.com.

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