Is there an increased risk of fire with solar roof panels?
No doubt you read about Walmart’s lawsuit against Tesla last year, alleging that Tesla’s SolarCity solar (also called photovoltaic) panels caught on fire at seven Walmart locations, causing extensive damage. For Walmart, there was definitely an increased fire risk with solar roof panels.
The suit accused SolarCity of failing to install the panels properly, saying their own inspectors identified multiple issues but failed to repair them. The problem was not with the panels themselves, but with faulty installation, broken panels and faulty wiring.
In third quarter 2019 alone, some 2.6 gigawatts of solar capacity were installed to reach a total of 71.3 GW installed capacity, enough to power 13.5 million American homes. Total installed U.S. capacity is expected to more than double over the next five years, says SEIA.org.
So are solar panels on the roof of your commercial building a safe bet or not? In general, it all comes down to the installation.
“Electrical fires are one of the most common causes of loss in general, and a lot of solar installations, which are very complex electrical systems, are put on roofs that aren’t necessarily designed with that fire risk in mind,” explained Jim Breitkreitz, executive technical director of risk engineering for Zurich North America in an article on the solar market. “Additionally, installations increase the combustible loading of the roof because solar panels contain a significant amount of plastic. The biggest impact may be the way the solar panels encourage horizontal fire spread across the roof, under the panels.”
In addition to the risk of electrical fires, solar panels can add a significant weight load to an existing roof. They can also trap debris to feed a fire and snow or ice, adding weight to the roof. Then there’s the added concern that in the event of a fire, the panels can complicate firefighting efforts.
“Firefighters typically will not go on a roof that has a solar panel installation if that roof is on fire, because they are concerned about the risk of electrical shock,” Breitkreitz said. “Water and electricity don’t mix, and the only way to shut off the electricity generated by solar panels is to wait for the sun to go down.”
And strangely enough, the illumination trucks that firefighters bring to nighttime emergencies can give off enough light to electrify a photovoltaic system, causing additional complications and risks.
Precautions to take to decrease fire risks with solar roof panels
Prior to installation – and in the planning stages – property owners and insurance agents should be aware of the increased fire risk with solar roof panels, ensuring that the panels are installed as part of an integrated system that takes into account an increased weight and fire load. You’ll also want to consider the ongoing costs for maintenance of both the solar-generation system and increased building maintenance costs, such as a regular replacement of flat-roof surfaces.
TheSolarNerd.com also gives these tips while you’re in the assessment and planning stage:
- Screen your solar contractor very carefully.
- Get several quotes, but don’t rely on solar price comparison websites alone.
- Don’t select a company based only on price; instead, choose from among local companies that’ve been in business for a long time.
- Check contractors’ licenses. You can review the type of license required in your state on the Interstate Renewable Energy Council’s website.
- Ask about warranties. Each component in the photovoltaic system has its own warranty from the manufacturer, so make sure you understand the limits of each one.
- Ensure that each piece of equipment is spelled out in the contract by manufacturer and model number.
For additional help, review their checklist to use in evaluating your solar quotes.