The European Patent Office (EPO) has removed a legal barrier that would have affected European solar module manufacturers using multi-busbar (MBB) cell technology.

It has revoked patent EP4092759B1 that applies to MBB technology used to manufacture solar panels. This patent, first owned by the Korean electronics company LG Electronics, was acquired by China’s solar solutions company JA Solar.

MBB technology uses numerous thin metal strips, or busbars, to collect and transfer energy from solar cells.

Most European module makers rely on round-wire MBB architectures to reduce shading losses, lower resistance, cut silver consumption, and ensure reliable long-term electrical connections.

The EPO’s decision follows a claim supported by the European Solar Manufacturing Council (ESMC) and a consortium of solar manufacturers and research institutes from the continent. This procedure was filed in October 2024 with the support of an intellectual property law firm.

Christoph Podewils, Secretary General at ESMC, said, “This patent was on matters which are industry standards now for a long time. Had it remained in force, the vast majority of European module manufacturers using multi-busbar cells would have risked infringement despite applying well-established technologies.”

The revoked patent was a divisional patent that was derived from an earlier European filing claiming priority from 2014. It sought protection for solar cells with six or more busbars, the utilization of solder-coated round wires as interconnection leads, and the use of expanded pad sections to solder these wires to the busbars.

ESMC stated that multi-busbar features had been publicly known for some time and were documented and widely used for over a decade. This technology was developed in Europe around the early 2010s. It has since become a standard in global solar manufacturing.

Podewils said EPO’s rulings will ensure a level playing field and support the solar industry’s competitiveness by allowing open access to the development of multi-busbar technologies.

The losing party can appeal the EPO’s decision by January 7, 2026. The grounds for appeal due by March 7, 2026.

Rising solar technology innovation and increasing solar market have led to multiple intellectual property disputes in recent years.

Solar module and cell manufacturers LONGi Green Energy Technology and JinkoSolar recently announced that they have reached a global settlement regarding ongoing patent disputes and related legal proceedings.

JA Solar was also involved in patent disputes with another Chinese solar manufacturer, Astronergy. The EPO resolved this issue in 2024 by confirming the validity of JA Solar’s patents concerning TOPCon solar cell technology, strengthening its position in its ongoing litigation against Astronergy, another Chinese solar manufacturer.