Enercon GmBH admits to invalid patents before the U.K. Courts but defends the same before the IPAB

Subsequent to our earlier posts on the Enercon patent litigation, we’ve received information that two of the European equivalents, of patents revoked by the IPAB, were also revoked by a High Court in the U.K., four years ago, during the course of litigation between Dr. Wobben (Owner of Enercon GmBh) and Vestas-Celtic Wind Technology Ltd. A third patent revocation is still pending before the IPAB. The most striking feature of this judgment is that it records that Dr. Wobben has himself admitted to the U.K. Court that some of his own patents are invalid.

In pertinent part Justice Kitchin notes that “Originally four patents were in issue but one, European Patent (UK) No 1,282,774, is now accepted to be invalid.”

In regards another patent (EP ‘691) Justice Kitchin states that “It is accepted that claim 1 of the patent is invalid. As I shall explain, there are before me no fewer than three applications to amend 691.”

In regards the third patent (EP ‘078) Justice Kitchin states that “It is now conceded by Mr Wobben that all the claims are invalid except for claims 6 and 7. Consequently I have before me an application to amend the patent.”

Despite this Dr. Wobben sought to defend the same patents in India. As per the IPAB Order, the Indian equivalents of these patents contain mostly the same claims as their U.K. patents.
Image from here.

As per Section 31 of the Evidence Act, 1872 although certain admissions may not be conclusive they will still estop the person from changing his stance later. Therefore Dr. Wobben cannot go back on the admissions that he made before the U.K. Court.

This also clearly contradicts Enercon GmBH’s statements to the German press that the patents revoked by the IPAB are valid in all other jurisdictions such as the U.S., E.U. and Japan.

The two patents in questions which have already been revoked are:

(i) Indian Patent No: 197959 revoked by the IPAB, in Order No: 239 of 2010. (The IPAB order lists the equivalent patent in the U.K. as EP 1040564 & EP 1164691 both of which were derived by dividing PCT/EP98/08324).

(ii) Indian Patent No: 202887 revoked by the IPAB, in Order No: 244 of 2010. (Equivalent patent in the U.K. is EP1282774).

Resources: The IPAB orders in both of the above matters are available over here and here on the SpicyIP website. The U.K. judgement is available over here.

(i) Dr. Aloys Wobben v. Vestas-Celtic Wind Technology Ltd. [2007] EWHC 2636 (Pat): This was originally a suit for patent infringement filed by Dr. Aloys Wobben against Veltas, a Danish company and the largest manufacturer of wind-turbines in the world.

(a) Originally four patents were at issue but as Justice Kitchin notes in the very beginning of his judgment, one of the patents i.e. EP1282774 was accepted to be invalid by the Plaintiffs themselves.

(b) Dr. Wobben also conceded that another patent of his, EP 1386078 was also invalid, except for Claims 6 and 7. The ‘078 patent is also pending revocation proceedings before the IPAB. (Although the petition was heard it could not be decided by the Bench before the Technical Member retired because of which the matter will be re-heard by a new Bench.)

(c) The two remaining patents i.e. the ‘564 patent and the ‘691 patent were also held to be invalid by Justice Kitchin. Claim 1 of the ‘691 patent was accepted to be invalid by Dr. Wobben before the U.K. Court and he requested for permission to amend the same. The final order held both patents to be invalid and permission was not granted to amend the same.

Apart from the United Kingdom, Enercon has also lost patent infringement battles back home in Germany (Thank you to the anonymous commentator for the German Supreme Court tip!).

(ii) Order No. 239 of 2010 of the IPAB revoking Indian Patent No. 197959: As already explained above the European equivalent to this Indian patent is EP 1040564 and EP ‘691. A revocation petition was filed against this patent before the IPAB in January, 2009. As noted by the IPAB, the counsel for the petitioner, Mr. S. Parthasarathy, Senior Partner at Lakshmi Kumaran and Sreedharan (who argued all the revocation petitions before the IPAB), at the very outset brought the Court’s attention to the judgment of Justice Kitchin in the U.K. and explained how the respondent’s EP patent had been revoked via that order. More pertinently however it was pointed out to the IPAB that the patentee himself had accepted, before the U.K. Court that Claim 1 of the EP Patent, which was identical to the Indian patent, was invalid and had sought to amend the same.

The counsel for the patentee, while maintaining his silence on Claim 1, informed the Court that the U.K. decision was not binding on the IPAB and that patent law was a national law and hence differed in standards. The IPAB bought the argument and categorically stated that the U.K. decision cannot be a ground for revocation and the petitioner would have to establish the invalidity of the patent on the basis of Section 64. (para 163). After analysing all of the prior art and arguments the IPAB proceeded to revoke Wobben’s patent after rejecting all requests for amendments.

(iii) Order No: 244 of 2010 of the IPAB revoking Indian Patent No: 202887: As already explained, patent no: 202887 was equivalent to EP1282774 in the U.K. Before Justice Kitchin, the patentee had admitted that Claim 1 was invalid and had moved amendment applications for the same. Justice Kitchin did not allow any of the amendment applications and the entire patent was eventually revoked. The IPAB also proceeded to revoke the same patent after rejecting all the amendments in a lengthy 70 pages order.

Conclusion: It would therefore be wrong to be under the presumption that Enercon GmBH has not had its patents revoked in any other country.

Prashant Reddy

T. Prashant Reddy graduated from the National Law School of India University, Bangalore, with a B.A.LLB (Hons.) degree in 2008. He later graduated with a LLM degree (Law, Science & Technology) from the Stanford Law School in 2013. Prashant has worked with law firms in Delhi and in academia in India and Singapore. He is also co-author of the book Create, Copy, Disrupt: India's Intellectual Property Dilemmas (OUP).


  1. Anonymous

    Your comments on this post to some extend contradict with para vi of your earlier post.
    “(vi) But Enercon GmBH’s patents have been held valid in more advanced jurisdictions like the E.U., U.S. & Japan…..

    This is the most nonsensical of arguments against the IPAB decisions to void the patents. Just because a patent has been granted does not mean it cannot be revoked and this is the position worldwide.”

    On the same line a patent refused in another country should not be the deciding factor for the validity of the patent in India.

  2. Prashant Reddy


    Who ever said that the U.K. orders should be the basis of revoking the Enercon’s patents in India. I’ve clearly pointed out that the IPAB itself did not buy this argument and as a result heard out the entire suit.

    In any case there is an ocean of a difference between a Court striking down a patent and a patentee himself admitting that the patent was invalid. Imagine filing a suit for patent infringement for four patents and then admitting that 3 of them are invalid!

    Besides the entire point of this post as noted in my conclusion is to rebut Enercon’s assertion that its patents have been upheld in all other jurisdictions.



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