A piece of solar safety equipment that was the subject of a fight over patent rights has emerged from the dust-up with both sides claiming at least partial victory.
The fight was over rapid shutdown technology, a safety function for rooftop mounted solar photovoltaic systems that is designed to reduce the risk of electrical shock to emergency responders. Rapid shutdown is widely mandated by building codes and regulatory bodies around the U.S.
At the heart of the dispute was a specification put forward by the SunSpec Alliance, a San Jose, Calif., based open information standards and certification organization for the distributed energy resources industry. Tigo Energy alleged that SunSpec and some of its member companies infringed on its patents, referred to in shorthand as the “‘321 and ‘770” patents.
In two February 2022 filings with the U.S. Patent and Trademark Office, SunSpec challenged parts of Tigo’s ’321 and ’770 patents. SunSpec said it had previously published a white paper as well as work known as a “prior art study” that it said Tigo used for at least two basic elements of its rapid shutdown approach.
One element was a controller that serves a watchdog timer. A second was a “heartbeat signal” that the controller detects to know when to reduce a solar panel’s power output as a result of a skip or other anomaly.
On those two claims, SunSpec claimed victory when the Patent Office issued its decision in the dispute in late January.
“Because of the Patent Office’s decision on these claims of the ‘770 patent, Tigo will not be able to assert them against any company in the future,” SunSpec said in a statement.
But the Patent Office declined to support SunSpec’s other challenges related to the ‘770 and ‘321 patents. That gave Campbell, Calif., based Tigo a chance to claim victory of its own. It said the Patent Office rejected 80% of the claims that SunSpec had made.
It pointed out that the Patent Office ruled in its favor on all challenges to its Patent No. 8,933,321. And the Patent Office denied challenge to the validity of all but two claims leveled against its U.S. Patent No. 10,256,770.
“We welcome this ruling by the U.S. Patent Office,” said Zvi Alon, chairman and CEO at Tigo Energy, in a statement. He said that as with previous patent challenges, Tigo would offer “reasonable and non-discriminatory licensing terms” to SunSpec Alliance members.
Tigo said it had prevailed in a previous patent infringement case and currently has an open lawsuit involving six patent infringement claims against SMA Solar Technology America, a SunSpec Alliance member.
SunSpec said it is still considering its options, including a possible appeal of the Patent Office decision.