Solar panels on a tall building

Amazon switched off its solar rooftops after fires, report says

Image credit: Foto 10189490 © Rido |

Six separate instances of fires caused by solar panels atop Amazon fulfilment centres led the company to power down the technology, CNBC has revealed.

Amazon reportedly took all US solar rooftops offline last year after they caused at least six "critical fire or arc flash events" in warehouses between April 2020 and June 2021, affecting 12 per cent of such facilities. 

“The rate of dangerous incidents is unacceptable and above industry averages,” an Amazon employee wrote in an internal report viewed by CNBC, which described the company's intention to ensure its systems were designed, installed and maintained properly before “re-energising” any of them.

The solar rooftop programme was launched in 2017, followed two years later by founder Jeff Bezos' Climate Pledge, promising the largest online retailer would zero out emissions by 2040. By April 2022, Amazon had onsite solar at 176 facilities, according to its website. 

In Amazon’s 2021 sustainability report, released last month, the company claimed that 115 of its warehouses worldwide were being powered by rooftop solar installations, up from more than 90 in the middle of the year. The report made no mention of the fires, nor of the steps that were taken to avoid them happening again.

However, a CNBC investigation has revealed that on the afternoon of April 14 2020, dozens of firefighters arrived at an 880,000-square-foot Amazon warehouse in Fresno, California. Approximately 220 solar panels and other equipment at the facility were damaged by a three-alarm fire, which was caused by “an undetermined electrical event within the solar system mounted on top of the roof,” according to an incident report from Fresno's fire investigator. 

In the intervening months, at least five other Amazon fulfilment centres caught fire or experienced electrical explosions due to failures with their solar energy-generating systems, according to internal company documents viewed by CNBC. 

Amazon spokesperson Erika Howard told CNBC in a statement that the incidents involved systems run by partners and that the company responded by voluntarily turning off its solar-powered roofs.

“Out of an abundance of caution, following a small number of isolated incidents with onsite solar systems owned and operated by third parties, Amazon proactively powered off our onsite solar installations in North America and took immediate steps to re-inspect each installation by a leading solar technical expert firm,” the statement said. “As inspections are completed, our onsite solar systems are being powered back on.” 

After the fires, Amazon reportedly hired Denver-based CEA to conduct a third-party audit of its rooftop solar systems. Late last year, CEA informed Amazon of one critical and 259 major findings across Amazon’s rooftop solar portfolio. Problems included mismatched module-to-module connectors, improper installation of connectors, poor wire management and evidence of water intrusion in the inverters, internal documents said. 

Issues with inverters, which convert solar energy into usable electricity, were identified as the likely cause of a fire in at least one Amazon warehouse. The Fresno fire investigation report concluded the blaze at Fulfilment Centre FAT1 “originated on or near two inverters".

Amazon blamed third-party partners and vendors for the most significant problems uncovered by CEA and other teams working on facilities and sustainability initiatives.

“Over the past five years, solar malfunctions have been caused by improper installation techniques, improper commissioning of a new system, inadequate system maintenance and equipment malfunction,” the documents said.

In the internal report obtained by CNBC, an Amazon employee estimated that each incident cost the company an average of $2.7m (£2.3m), to account for third-party audits of rooftop solar systems, checks on how much electricity they were generating and repairs for any broken or faulty parts of the systems that inspectors identified. The employee also revealed Amazon would lose $20,000 (£17,280) for each of the 47 decommissioned North American sites, as long as the solar remained offline.

In a 2020 investigation, E&T uncovered a backsheet design flaw that affected millions of solar PV solar panels, built with cheap materials less than a decade ago and sold across the world. 

Sign up to the E&T News e-mail to get great stories like this delivered to your inbox every day.

Recent articles