CASE BRIEF: Alloys Wobben v. Enercon (India)

Introduction 

The case concerns the revocation of Patent No: 201538, which was granted to Dr. Aloys Wobben for the invention titled “A method for operating a wind turbine with an electrical generator and a wind turbine with an electrical generator.” The patent application was filed on October 22, 2003, with a priority date of April 24, 2001, and the grant was published on February 23, 2003. The case was initiated by Enercon India Limited, which sought the revocation of this patent, claiming that the patented invention lacked novelty and an inventive step, particularly regarding its utility in varying the phase angle of power supplied to the electrical grid.

The proceedings included various hearings and discussions that involved past judgments from UK courts regarding similar claims, where it was established that several claims of the corresponding European patent had already been admitted as invalid. Notably, in the course of the hearings, it was highlighted that the respondent (Dr. Wobben) had accepted the invalidity of multiple claims except for claims 6 and 7 in the UK courts. Throughout the case, both parties presented detailed arguments regarding the patent’s validity, the implications of amendments, and the prior art concerning wind turbine technology.

This case showcases the intersection of patent law and technological innovation within the renewable energy sector, particularly focusing on the criteria for patentability and the ongoing developments in wind energy converter technologies.

Facts of the case 

Here are the key facts of the case concerning the revocation of Patent No: 201538:

1. Patent Grant and Description: Patent No: 201538 was granted to Dr. Aloys Wobben for a method related to operating wind turbines with electrical generators. This involved varying the phase angle of the power supplied to the electrical grid based on voltage ranges.
2. Filing and Priority Dates: The patent application was filed on October 22, 2003, with a priority date of April 24, 2001. The grant of the patent was published on February 23, 2003.
3. Revocation Application: Enercon India Limited filed an application for the revocation of this patent, arguing that it lacked novelty and inventive steps, specifically in light of existing knowledge and improvements in grid compatibility for wind energy converters.
4. Amendments and Legal Proceedings: The Intellectual Property Appellate Board (IPAB) heard the case, which had been previously considered by an earlier board but was delayed due to the retirement of a member. The case was re-listed for hearings and subsequently took place on April 18, 2013, and May 13, 2013.
5. UK Judicial Context: Prior to the Indian hearings, UK court rulings (particularly in the cases of Alloy Wobben v. Vestas Wind Technology) found that several claims related to the same invention were invalid. The respondent had admitted that all claims except for claims 6 and 7 were invalid in the UK context.
6. Counsel Representation: The applicant was represented by learned counsel Mr. R. Parthasarathy, while the respondent (Dr. Wobben) was represented by Mr. Praveen Anand. Both counsels presented arguments regarding the validity of the claims based on the previous UK judgments and the subsequent amendments made to the patent claims in India.
7. Claim Adjustments: During the proceedings, it was noted that the respondent had amended several claims to correspond to those granted in the UK, particularly following the UK court’s decision that held amended claim 1 as valid. However, claims 6 and 7 remained the focal point of defense since they were the only claims conceded as valid by the respondent in previous court findings.
8. Inventive Step Argument: The applicant’s counsel argued that the invention lacked an inventive step and was obvious based on existing technologies and practices in managing voltage fluctuations in electrical grids, citing prior art documents as evidence.

These facts collectively highlight the complexity of patent law and its challenges, particularly regarding innovation in the context of renewable energy technologies. They underscore the importance of prior art, the role of judicial precedents, and the technical arguments presented in patent validity disputes.

Arguments by the parties 

Applicant’s Arguments (Enercon India Limited)

1. Invalidity of Claims: The applicant’s counsel, Mr. R. Parthasarathy, argued that the patent claims lack novelty and an inventive step, specifically based on prior art and existing technologies related to wind energy converters. They contended that the claimed invention was obvious to a person skilled in the art.
2. Acceptance of Invalidity: It was highlighted that in prior UK court rulings (notably Alloy Wobben v. Vestas Wind Technology), the respondent had admitted that all claims except for claims 6 and 7 were invalid. The applicant emphasized that the respondent should not be allowed to argue that the claims as granted should stand in India after having accepted their invalidity in the UK.
3. Delay in Amendments: The applicant pointed out the inordinate delay in the respondent’s amendments to the patent claims. They noted that the amendments proposed were made after a clear acknowledgment of invalidity of most claims in the UK.
4. Obviousness: The applicant argued that the improvements proposed in the patent, particularly the method of changing the phase angle to control voltage in the grid, were already known in the field and thus obvious. They presented prior art documents, such as “Improvement of the grid compatibility of wind energy converters” (D5) and Benchmark (D8), which described similar technologies.
5. Technical Details: They elaborated on the technical aspects, explaining that the phase angle’s adjustment to prevent voltage fluctuations in the grid did not demonstrate an inventive step since it was achievable through common engineering practices at the time.

Respondent’s Arguments (Dr. Aloys Wobben)

1. Defense of Remaining Claims: The respondent’s counsel, Mr. Praveen Anand, stated that they were only defending claims that had been previously granted by the UK court (claims 6 and 7). He emphasized that these claims had been found valid in earlier proceedings and should be preserved in the Indian context.
2. New Amendments Corresponding to UK Grants: The respondent proposed amendments to the Indian patent claims to align with the claims that were accepted in the UK court, asserting that these amendments clarified and validated the assertions of novelty and inventive step.
3. Complexity and Testing of Claims: The respondent pointed out that the UK court allowed the claims after thorough examination and cross-examinations during a full trial, suggesting that the findings of the Hon’ble Justice Kitchin should not be disregarded given the meticulous nature of the trial.
4. Technical Value of Claims: The respondent argued that the claims provided substantive innovation in managing voltage fluctuations in electrical grids with wind turbines, which was essential for improving grid stability—an area of significant importance in renewable energy.
5. Claims’ Novelty and Utility: The respondent contended that the invention fulfilled a critical need for the industry by improving the integration of wind energy into existing grid systems and mitigating issues that arose with voltage integrity.

In summary, the applicant pushed for revocation of the patent based on arguments of lack of novelty, obviousness, and previous admissions of invalidity. Conversely, the respondent focused on defending specific claims that had been previously validated in other jurisdictions and emphasized the technical advancements their invention provided in the renewable energy sector.

Judgement of the case 

The judgment regarding Patent No: 201538, as outlined in the provided documents, focused on several key aspects of patent validity, particularly in the context of prior judicial findings and the arguments presented by both parties. Below are the main points of the judgment:

1. Recognition of Prior Judicial Findings: The Intellectual Property Appellate Board (IPAB) acknowledged the prior judgments made by the UK courts concerning the corresponding European Patent (EP) UK Patent No. EP1386078. The board indicated that the findings of invalidity regarding most claims (except claims 6 and 7) in the UK should be taken seriously in evaluating the claims in India.
2. Invalidation of Claims: It was determined that the respondent’s earlier acceptance of the claims’ invalidity in the UK significantly impacted the case. The IPAB noted that the respondent had amply recognized that all claims except for claims 6 and 7 were invalid and had amended the claims accordingly in the UK.
3. Claims As Granted vs. Amended Claims: The ruling highlighted that while amended claims derived from the UK court’s decision could stand on their own, the original claims as granted (which included claims deemed invalid in the UK) could not be defended effectively by the respondent.
4. Assessment of Inventive Step: The IPAB evaluated the arguments regarding the inventive step of the patent. The applicant convincingly argued that the method described in the patent was not a novel improvement and was essentially an obvious solution known in the field. The tribunal appeared to favor the applicant’s position that the invention lacked the required inventive step.
5. Evidence and Expert Testimony: The judgment also addressed the requirement for specific evidence to support claims of non-obviousness. The IPAB found that the applicant had discussed the matter primarily through judicial precedents and lacked substantial expert evidence to support their claims of invalidity.
6. Outcome: Ultimately, the IPAB ruled in favor of revoking Patent No: 201538, affirming the arguments put forth by the applicant regarding lack of inventive step based on existing technologies and prior invalidation of the majority of claims in previous jurisdictions.

In summary, the judgment concluded that the patent was not valid due to its lack of novelty and inventive step, emphasizing the binding nature of previous judicial findings and the failure of the respondent to provide compelling grounds to uphold the patent claims in the Indian context.