Wind business: Patent inventor now in dispute

New twist in GE v Mitsubishi

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Windpower Monthly Special Correspondent Intriguing details have emerged in the cut-throat fight between rivals General Electric Corp and Mitsubishi Heavy Industries over the use of intellectual property in Mitsubishi's flagship 2.4 MW wind turbine. A new inventor of one of GE's key wind patents has been named by the administrative law judge who has been overseeing the case at the US International Trade Commission (ITC) in Washington DC. The new co-inventor, Thomas Wilkins, is a California-based power systems engineer not employed by GE.

Judge Carl Charneski's finding on co-inventorship, if upheld, could mean that GE does not have the rights to "assert" the patent in question, known as 985 and issued for GE's low voltage ride-through (LVRT) technology. On most power systems, wind turbines are required to "ride through" incidents of momentary low voltage on the grid without tripping offline. GE's LVRT patent does not expire until January 2023. As an inventor, Wilkins could collect a portion of GE's royalties for the patent, issued in 2003. GE licenses a suite of its wind rights - including 985 - to competitors in the US for as much as $25,000 per installed megawatt.

Wilkins could also assign his rights to another party without permission from GE. His status as an inventor could ultimately mean that GE's case against Mitsubishi over 985 at the ITC must be terminated - unless Wilkins becomes party to GE's complaint. Termination is the current recommendation of staff at the ITC's Office of Unfair Import Investigations, which acts as a third party in commission disputes. At the seven-day ITC trial in May, Wilkins testified for Mitsubishi.


Wilkins' alleged contribution was detailed in Charneski's initial determination on the patent case, issued in August (Windpower Monthly, September 2009). A full public version of the ruling, with confidential commercial details deleted, only became available when it was filed by GE last month with its patent lawsuit against Mitsubishi (see box). Charneski's ruling is subject to review by the full ITC. Wilkins declines to comment.

GE vehemently disputes that Wilkins is an inventor and notes that GE owns the patent. The company, which is introducing its 2.5 MW wind turbine in America in 2010, declines to comment on the case. Mitsubishi is delighted with Charneski's finding in relation to Wilkins. "We think that it is a correct decision," says Roger Taylor, a lawyer representing Mitsubishi.

Two further patents are also in dispute: GE's 039 patent, for technology connected with variable speed turbine operation, which expires in 2011; and GE's 221, also for a form of LVRT, which expires in 2023. Modern wind turbines generally run at variable speed and LVRT is a standard requirement. Companies wishing to compete with GE on the American wind turbine market must either invest in technically circumnavigating the patent or license the 039 technology from GE. The patent, under previous ownership, was at the centre of a high-stakes international dispute between US and European companies, starting in 1995.

In addition to naming Wilkins, Charneski finds that three models of Mitsubishi's flagship 2.4 MW turbine violate each of the patents in question. Those turbine models are the MWT92 and MWT95, and a later version known as the EPSS.

In the case of the 985 and 039 patents, Charneski finds that Mitsubishi is violating Section 337 of the Tariff Act by importing its 2.4 MW turbine into the US. The judgement could lead to the turbine configurations being banned from the US as soon as February 2010. Charneski, however, finds that GE is not using the 221 patent in America, so there is no import violation.

By October 6, the ITC is to decide whether to review Charneski's initial determination. Mitsubishi is seeking a review of Charneski's findings of patent infringement and that GE unintentionally omitted Wilkins' name on the patent. Intent can be hard to prove, especially years after alleged "inequitable conduct," a concept that could lead to a patent being unenforceable. For its part, GE is seeking to have Charneski's inventor finding set aside. It describes the matter to the ITC as a "classic red herring" and is seeking to prove that it does use the 221 patent in America.

Six inventors

Wilkins was listed as one of six 985 inventors when GE first applied for the patent in 2003, a fact not in dispute. But GE says that listing Wilkins was a "mistake" later rectified: two to three months after the application was filed, Wilkins name was removed after discussion by senior lawyers working for GE. MHI argues that Wilkins' claim as an inventor has been corroborated in documents and in testimony from one of the named inventors of 985, power engineer Henning Lutze from Germany.

Wilkins' employment status when 985 was applied for - and whether he was obliged to assign his rights to GE - are crucial. He had been employed by Enron Wind and was kept on by GE in 2002 when it took over Enron Wind. But he left GE shortly before the application was filed, states Charneski, adding: "In fact, it appears that as a former Enron Wind employee who was kept on at GE without a new contract, (Wilkins) did not have an obligation to make an assignment (of his rights to GE)."

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