Our CEO and all-around solar educator Herve Billiet recently spent the better part of a week in July talking with Northern Virginia and Washington, DC firefighters about doing their job in the presence of solar panels on a home's roof. Here are 5 facts the emergency responders came away with that might surprise you too!
1. Solar panels are safe to step on
By far, the top question firefighters wanted answered was, is there more a risk of slipping or taking a misstep on a solar panel than on regular roof. Normally, they would avoid stepping on the solar panels if possible.
This wouldn't be too hard normally, as installers customarily leave setbacks along roof edges and ridges to provide more panel-free space. Sometimes though, installers like Ipsun will get a setback requirement waived in order to better fit panels on limited roof space.
But if the home is really engulfed, it could be necessary to worry less about keeping from damaging solar panels and stand wherever they can most effectively combat the blaze. They were happy to learn that a solar panel is hard and sturdy, and while it will likely crack underfoot it can be stepped on in an emergency without risk to the fire crew member.
2. If fire strikes, throw the solar shut-off switch
Herve showed the fire fighters where to make sure the solar system is shut down in the event of fire. It helped the emergency responders to know that they can be confident that no wires in the house are energized once they do this. A homeowner can even do this if they think something unsafe is going on in their home and they need their solar system deactivated, like if a tree fell on the home. Depending on the inverter brand, there may be an on/off dial there that can also be turned to the off position.
3. It's super rare for solar components to cause a fire
Electrical inspections by the city or county where the city is located help ensure that the project will operate safely and reliably for its warrantied lifetime of 25 years and beyond. In our area, fires originating specifically from solar components are unheard of, and overall this is an extremely rare occurrence. As home batteries enter our market, we plan to follow up with fire crews about what to look for in preventing the chemical battery banks from experiencing thermal runway in the heat of a serious fire, however solar systems do not normally have batteries.
4. Few of the solar panel parts are combustible
While the solar panels may change the dynamics at work in a roof that's already on fire, very little of the solar module itself can actually burn. The insulating rubbery plastic on the outside of the cables and some of the back sheet may be combustible, however the tempered face of the panel and the framing would heat without burning.
In DC, firefighters can expect to often see panels installed on a roof secured from wind and motion by either anchors or a ballasted (weighted) system of cinder block or stone, whereas on sloped roofs the panels tend to be mounted on racking attached to the roof with thick screws and bolts.
5. Solar shuts down by itself in a grid outage
Unless the customer has a backup battery system for storing their solar energy to use when the grid goes down, if the lights are out then so is the solar. The panels won't be producing any electricity if there has been a grid outage for any reason - like a down tree knocking out an overhead line, a substation failure, or a brownout from congestion on the system. It's easy to check, but typically this automatic disconnect feature is there to protect line workers, emergency workers, and residents from shock and to reduce fire risk in a disaster situation. In the event of a fire, flood, or other serious act of nature or mishap, the homeowner should also know where their inverter on/off switch and AC disconnect are and be able to operate them. That's one way to be a responsible partner with firefighters in a dangerous event.
Bonus fact: Regardless of labels, assume system is working
Ipsun is always thorough about labeling system components with bright red stickers that hold up through weather like rain, UV exposure and heat and cold, as in the image above. Some solar installers aren't as assiduous or have used labels that degrade quickly, but nonetheless even if labels are inconsistent the systems should be operating as designed. We recommend always assuming that a solar system is producing power until you can tell otherwise!
Ipsun is happy to take the care and time necessary to familiarize community members like fire fighters with the basics of solar. We loved meeting the hardworking, courageous, highly-skilled firefighters in our community and learning from each other about keeping solar homes safe!