Walmart sues Tesla over solar panel fires, accusing the car company of 'gross negligence'

US supermarket chain Walmart is suing Tesla over a series of solar panel fires it says were the result of the company's negligence.

The California-based battery and electric car company had an agreement with Walmart to install solar panels on the roofs of its shops across the US.

In a lawsuit filed in New York, Walmart alleges that fires at four branches during 2018 were down to Tesla's equipment, and that four other fires dating back to 2012 were also linked to the solar panels.

Tesla, which bought solar panel firm SolarCity in 2016, was responsible for the fires due to its "gross negligence and failure to live up to industry standards", Walmart said in court documents.

"Why were multiple Walmart stores located all over the country suddenly catching fire? The answer was obvious and startling: the stores all had Tesla solar panels installed by Tesla on their roofs. At each location, the fire had originated in the Tesla solar panels," the lawsuit says.

The panels had been installed in more than 240 Walmart stores, with Tesla taking responsibility for maintaining the equipment, Walmart said.

The firm also alleges that Tesla technicians did not know how to use maintenance and testing equipment and failed to identify potential problems at the solar panel sites.

The maintenance problems and resulting fires were the result of "systemic Tesla malfeasance", Walmart argues.  It said all the panels were disconnected after three fires in the spring last year, but a fourth broke out anyway in November.

Solar City, founded in 2006 by Peter and Lyndon Rive, cousins of Tesla chief executive Elon Musk, leased solar panels to customers in exchange for 20 years of payouts, though in recent years it has shifted to a business model based on selling the panels to consumers upfront because of financial difficulties. Tesla bought the firm for $2.6bn in August 2016.

Tesla did not immediately respond to a request for comment, and as of Tuesday afternoon had not filed a response to the Walmart complaint.