A small fire shut down a generating tower last week at the world's largest solar power plant, Ivanpah Solar Electric Generating System in California.
According to an Associated Press report, the fire left the sprawling facility on the California-Nevada border operating at only a third of its capacity.
The plant works by using mirrors to focus sunlight on boilers at the top of three 459-foot towers, creating steam that drive turbines to produce electricity. But some misaligned mirrors instead focused sunbeams on a different level of Unit 3, causing electrical cables to catch fire, the AP reported.
Firefighters had to climb some 300 feet up a boiler tower at the plant after fire was reported on an upper level. Plant personnel had the fire out by the time firefighters reached the spot, and it was officially declared out in about 20 minutes.
David Knox, spokesman for plant operator NRG Energy, said it was too early to comment on the cause, which was under investigation.