Renewable energy

Huawei and regular advisors succeed in revoking SolarEdge patent

The EPO Boards of Appeal have upheld a previous decision revoking an important SolarEdge solar technology patent. The decision also ends a lawsuit filed by SolarEdge against competitor Huawei in Mannheim, since the foundation for the first of the three suits has crumbled.

4 November 2021 by Mathieu Klos

SolarEdge, Huawei The EPO will not grant an important solar technology patent of SolarEdge following a successful defence by Huawei and its regular advisors Braun-Dullaeus Pannen Emmerling and Preu Bohlig & Partner ©一飞 黄 /ADOBE STOCK

It is a major win for Huawei’s defence against SolarEdge’s lawsuits over solar technology. In 2018, the Israeli solar technology manufacturer filed suit against competitor Huawei and its German sales company Wattkraft in Mannheim for infringing three patents. Now the European Patent Office has upheld the patent’s revocation.

In mid-October, the Boards of Appeal at the European Patent Office rejected SolarEdge’s appeal against the revocation of the patent in suit EP 29 30 839 B1 (case ID: TO678/20-3.5.02). The patent, which protected a multi-level inverter, is now obsolete. Furthermore, SolarEdge is likely to withdraw the lawsuit in Mannheim in the next few days before the Israeli company faces a costly dismissal of the infringement suit.

The market for solar technology is considered highly competitive. In 2019, Hanwha Q-Cells brought cases over solar technology against Jinko, REC and Longi before Düsseldorf Regional Court. Hanwha Q-Cells and Longi are also battling in France and the Netherlands over the technology.

Under new Rules of Procedure

Early in the appeal proceedings, the Boards of Appeal judges criticised how the patent claims did not list an essential feature of the invention. SolarEdge attempted to remedy this through several auxiliary requests before the oral hearing. But this was in vain, as the judges upheld the EPO Opposition Division’s revocation of the patent. The judges also did not allow the auxiliary requests, referring to the Boards of Appeal’s new Rules of Procedure (RPBA).

The EPO introduced the new RPBA in 2020. Under Article 13, after the Boards’ preliminary opinion, parties may only subsequently file in exceptional circumstances. However, SolarEdge’s auxiliary requests contained no such circumstances.

In fact, some EPO and BoA users criticise how the parties must now present all conceivable arguments in their statements right at the beginning of the appeal proceedings. EPO users observe how the boards now examine appeals more in terms of formalities, while giving less consideration to the technical aspects.

As such, the BoA judges did not examine whether the missing feature in SolarEdge’s patent specification might be obvious for the experts, even if it is not explicitly mentioned, as SolarEdge claims.

Two chances remain

Neither can SolarEdge remain hopeful for quick wins in the two other infringement suits against Huawei. In July 2018, it accused Huawei of infringing European patents EP 2 135 348 B1 and EP 28 59 650 B1 in Mannheim. All lawsuits are directed against inverters and optimisers, which are used in connection with solar cells to generate electricity. Huawei manufactures the products and Wattkraft is the largest dealer for the product in Germany.

In November 2019, Mannheim Regional Court dismissed the infringement suit over EP 348. SolarEdge appealed against the decision to the Higher Regional Court in Karlsruhe (case ID: 6 U 26/20). Then, in November 2020, the Federal Patent Court nullified the patent. SolarEdge subsequently appealed this decision to the Federal Court of Justice (case ID: X ZR 39/21). However, the court has not yet ruled on either appeal.

In June 2021, the Federal Patent Court upheld the third patent in suit, EP 650, although with limitations. Both SolarEdge and Huawei challenged the ruling (case ID: X ZR 79/21). In these infringement proceedings, the Regional Court Mannheim called in experts. The court will continue the oral hearing on 24 May 2022 (case ID: 2 O 113/18).

Meanwhile, in China, Huawei hit back by filing infringement suits against SolarEdge products. This, in one case, was successful.

Core advisors, different strategies

Andreas Schmid

Both companies rely on their core advisors in the German proceedings. SolarEdge has a long-standing client relationship with the Munich patent team of Hogan Lovells’ Steffen Steininger.

A few years ago, Hogan Lovells began to set up its own patent attorney department to advise on the technical aspects of litigation. The firm hired Andreas Schmid, one of its first patent attorneys, for this purpose. He then joined the Hogan Lovells partnership that year as the first patent attorney.

Initially, SolarEdge began the series of lawsuits with patent attorneys from Maikowski & Ninnemann.

One reason behind SolarEdge changing advisors from Maikowski to Hogan Lovells is perhaps that Andreas Schmid worked for Huawei in mobile communications suits before joining Hogan Lovells, which may have led to a conflict of interest.

In any case, Hogan Lovells works without the support of Maikowski & Ninnemann in other suits against SMA Solar. When the appeal proceedings started to hint at a negative outcome for EP 839, Hogan Lovells’ patent attorneys took over the entire proceedings. Originally, Dutch law firm V.O. filed the patent in suit EP 839.

Team talk

Preu Bohlig partner Christian Donle and patent attorney Friedrich Emmerling are a smoothly-operating team at the side of Huawei. The patent attorneys jointly conduct numerous lawsuits in Germany, mainly against NPEs. The team has conducted the case against SolarEdge since Huawei announced the suit.

Friedrich Emmerling

Friedrich Emmerling

Huawei also instructs Bird & Bird and Hoyng ROKH Monegier for German patent proceedings, mainly in the mobile communication sector.

Preu Bohlig and Braun-Dullaeus Pannen Emmerling also represent Wattkraft. At the beginning of the dispute, a team from Beiten Burkhardt represented the wholesaler.

For SolarEdge
Hogan Lovells (Munich): Andreas Schmid (patent attorney; lead revocation), Steffen Steininger (lead litigation) (all partners); associates: Katharina Bickel, Daniel Kaneko; Cédric Rohr, Niels Gierse (both patent attorneys)

For Huawei and Wattkraft
Braun-Dullaeus Pannen Emmerling (Munich) Friedrich Emmerling, Franck Klein, Jörg Kohlschmidt (all partners; all patent attorneys)
Preu Bohlig & Partner (Berlin): Christian Donle (partner); associate: Verena Kerscher

EPO Board of Appeal (3.5.02)
Richard Lord (chair), Harald Bronold, Wilhelm Ungler