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Wobben v Siemens [2015] EWHC 2114 (Pat)

Case Summary  |  Judgment  |  20 July 2015


Andrew Lykiardopoulos QC and James Abrahams appeared for the Claimant (“Wobben”) in this infringement and validity trial relating to Wobben’s patent concerning the operation of variable speed, variable pitch (“VSVP”) wind turbines at high wind speeds. James Whyte appeared as junior counsel for the Defendants (collectively “Siemens”) who denied infringement and claimed the patent was invalid for lack of novelty and inventive step in light of two pieces of prior art, “Shozaburo” and “Bossanyi”.

Birss J found the patent invalid for lack of inventive step, but not novelty. Shozaburo did not disclose the approach in the patent and to read it as doing so involved hindsight. Bossanyi taught continued operation of a fixed speed wind turbine in high winds through lowering power which reduced load and fatigue. The skilled person would be interested in implementing this on a VSVP machine at the priority date. Of the options available to implement Bossanyi on a VSVP machine an obvious one was the patent’s approach.

The judge found that if valid, the patent would not have been infringed. Siemens’ system did not reduce rotor speed depending on a rise in wind speed.

Andrew Lykiardopoulos QC and James Abrahams were instructed by Powell Gilbert LLP.
James Whyte was instructed by Bristows LLP.