- International data suggests that fires caused by rooftop solar power systems are rare; however, the United States doesnโt centrally track this information โ with the National Fire Data Center classifying them in the โotherโ category.
Per a conversation between pv magazine USA, and the National Fire Data Center, there is no information available on the number of fires from solar power systems, rooftop or ground. The group says, that they donโt have a code for it yet so they donโt track it, meaning these events end up in a very large โotherโ category. The National Fire Protection Associationย does have a solar photovoltaics safety related page.
Iโve got a feeling there are some who definitely donโt consider this anย โotherโ type of event.
In 2013, a warehouse in Delanco, New Jersey burnt to the ground. While there were issues with water supply at the site, firefighters were also unsure how to act due to 7,000 solar panels on the roof. This event was part of the logic that led to todayโs National Electric Code requirements for module level automatic shutdown requirements, to protect first responders against the risk of electricity flow even if main electrical switches to the site have been shut down.
Theย Japanese Consumer Safety Investigation Commissionย recently reported on 127 rooftop solar problems, โincluding firesโ, that occurred over a ten year period ending in November of 2017. Of those, thirteen led to fires from a modules or cable, and seven of those spread to the roof โ but all seven included modules directly attached to the structure (solar shingles?). As of October 2018, there were 2.4 million homes with rooftop solar in Japan.
Research by German groupย Fraunhofer ISE noted there were greater than 1.4 million solar power installations in the country. As of the date of publication, February 1, 2019, and going back 20 years, approximately 350 solar power systems โ 0.006% per Fraunhofer โ have caught fire. It was found that the solar system was at fault in 120 of those cases, with damage being severe in 75 cases โ and complete building loss occurring in ten cases.
Considering the US has about 2 million solar systems installed, the data above is quite comparable.
National Renewable Energy Lab (NREL) looked atย global solar power related fire standardsย and โ above image โ noted the challenges to be dealt with.
Most research notes that the equipment failures are even rarer than the fires themselves. Tightening connections is the number one challenge as loose connections can lead to sparks flying, which set nearby items on fire.
This general idea aligned with analysis on energy storage fires in South Korea, who found thatย in 23 eventsย all of them were related to installation and design versus equipment. As well, the Walmart vs Tesla event mostly talked about the quality of contract work versus hardware, though solar modules with hotspots were noted.
And though it wasnโt a rooftop system, we did recently had fire when a bird โflew into a pair of wires, creating an electric circuit and a shower of sparksโ and setting 1,127 acre fire that caused $8-9 million in damage at a 250 MW solar power plant, temporarily shutting down 84% of the facility.
Author: John Weaver
This article was originally published in pv magazine and is republished with permission.