Patent called in for examination

The US government has agreed to re-examine the patents held by Enron Wind for variable speed wind turbine technology. The decision, granting the request of attorneys for German turbine manufacturer Enercon GmbH, was unexpectedly issued on October 1 by the US Patent and Trademark Office. Such a re-examination often leads to a narrowing or rejection of the patent in question since the Patent Office is essentially agreeing that there are substantial new issues -- in this case of prior art -- that it was not aware of when first granting the patent.

Significantly, the Patent Office is not just re-examining the part of the patent that is disputed by Enercon. It says it is re-examining the entire patent, which includes 138 sub-sections or "claims" and which was originally awarded to Kenetech Windpower. Since Enercon turbines do not have induction generators, the German manufacturer was only questioning the part of the patent that deals with processing the electricity for the grid.

The entire patent -- which experts say is unusually broad -- is at the centre of the largest dispute over the ownership of intellectual property in wind turbine technology. The US International Trade Commission (ITC) has ruled that Enercon's turbines not only use power electronics for which a US patent exists, but they should also not be imported into the United States, or made within the US, until the year 2011.

The patent dispute has worldwide implications for wind energy development. In recent months Enron Wind has been pursuing similar patents through the European patent Office in Munich (Windpower Monthly, July 1998). The request for re-examination of the US patent was granted after Enercon presented three cases of "prior art" published more than one year prior to the application for the filing of the patent. The "prior art" was in the form of an academic book, a chapter from another academic book and a paper published by the IEEE, the international professional electrical engineering group. After reviewing Enercon's information, the US Patent Office, part of the Department of Commerce, agreed to determine whether the prior art raises "substantial question" on the suitability of the technology in question for patenting. All of the claims, 1 through 138, will be re-examined.

An estimated 100,000 to 150,000 patents are issued yearly in the United States. Perhaps 250 to 300 claims for re-examination are filed with the authorities. More than half or even three-quarters of those requests are granted. And most often they result in some sort of narrowing of the patent, or even a complete rejection. Few patents have as many "claims" as does Enron Wind's. Such a broad patent must mean that the technology truly was a startling breakthrough, or that the patent is too broad.

The US patent Office is not expected to issue a decision until late November or December. The patent holder then has 60 to 90 days in which to respond to that decision. That may happen several times until the process has been exhausted. The final decision can then be formally appealed, first through the Patent Office and then through federal appeals courts. If Enercon prevails, it would then be able to petition the ITC. And although the outcome does not have any direct bearing on the status of patents in Europe, it would provide information or findings of facts that can be presented to the European Patent Office.

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