Wobben Properties GmbH v. Siemens plc & Ors, UK, High Court (Patents Court), Birss J, 20 July 2015, Neutral Citation Number:  EWHC 2114 (Pat)
Wobben’s patent in suit concerned a method of operating a pitch-controlled wind turbine. The inventive concept of the claimed invention was to allow operation of wind turbines at wind speeds above the ordinary shut down wind speed (the speed at which a wind turbine is otherwise compulsorily shut down in high winds) so as to extend the operating window and potentially increase power yield as well as network compatibility. This continued operation involved progressively reducing the power and rotor speed of the turbine as the wind speed increased. The patent was held to be invalid for lack of inventive step over one of the cited pieces of prior art, and even if valid would not have been infringed by the defendants’ wind turbines.