Solar Panel Hurricane Countdown: Are Yours Secure?
4 Ways a Big Storm Can Impact Your Solar Panels
(And… The surprising truth many existing solar consumers don’t know about power outages and solar panels, and how you can watch TV while your neighbors sit in the dark)
Hurricane Matthew recently barreled through the Southeastern United States as well as several nations in the Caribbean. It knocked out power, caused floods, and leveled buildings.
With more homeowners and businesses installing solar panels than ever before, more people are asking how well their panels will withstand hurricane-force winds, and what happens if the power grid goes out in a big storm.
Here’s a countdown, in decreasing order of severity, of the four ways a storm can impact your solar panels. And these things can happen even if you work with a professional solar power installation company. Each one is followed by action steps you can take to plan ahead before the next big hurricane hits your area.
4) Nothing Is For Sure – Extreme Damage
If a tornado rips through town, or a hurricane blows the roof off your house, obviously your solar panels won’t still be there. So no matter what guarantees or extra secure mounting you might have used, it’s always possible it still won’t be enough.
In this worst-case scenario, if your home or business suffers major damage from a hurricane or tropical storm, your insurance should cover the costs to replace any lost or damaged solar panels. Take these two steps to minimize losses from extreme hurricane damage:
- Have insurance, and make sure it covers the costs to replace your panels and other components
- Expedite the process by having photos and documentation of your panels, if you ever find yourself in such a terrible situation
3) Wind-Force Testing – Keeping Your Panels Attached
Any successful solar panel manufacturer will run stringent testing procedures on their panels. They usually outsource this to a testing company like UL. But part of this includes wind-force testing.
According to UL Engineer Steven Jochums, almost all “building-integrated” solar panels far exceed the “minimum design load” standards for roof mounting. And there are different standards for different types of roofing materials. For roof-mounted panels, they also test for air pressure coming from below the panel as well as above it, because in a windstorm, often you’ll get a pressure differential between the panel and the roof.
Canadian Solar, the company Coastal Solar uses for most of our solar panels, meets or exceeds industry standards in all the major metrics, including:
- Snow and wind load
- Product quality manufacturing
- Temperature sensitivity
- Power output
But for wind resistance, how is testing done, and what affects a panel’s ability to withstand high winds?
There are six main variables that affect a solar panel’s performance in high wind
- Panel itself (type, weight, size)
- Mounting that fastens it to the roof
- Roof type
A typical panel weighs from 33 to 45 pounds. This is a non-issue though, as long as the other variables are addressed. The key is to position your panels so the wind can blow around them without putting pressure on them that will test the mounting.
And then, use enough mounting attachment points. The more places each panel is attached to your roof, the more secure the mounting. Solarworld, a solar panel manufacturer, offers an optional third mounting rail to the traditional two, which provides extra strength for high-wind areas. They also have a “peel” test that puts the panels out in real weather conditions to see if all the seals hold up.
The good news is, all this testing has paid off with a stellar track record for the industry. According to Bloomberg, one particular solar company has 6500 customers in the northeast US. During and after Hurricane Sandy, they didn’t hear from any customers about damaged solar panels. Not one out of 6500.
So, even in winds over 100mph, your panels should hold in place without any problems. The most extreme wind speeds push 150 to 170mph. But even there, as long as your roof holds in place, your panels should too.
The one caveat is – how healthy is your roof? If your roof is old, it may be wise to replace it before installing solar panels. The mounting has to “penetrate and anchor” to the roof, according to Solarworld, and a weakened, older roof might not be strong enough for this. (Note: if you replace your roof as part of an install, you can include the cost in your 26% federal tax credit!)
Here’s a well-known video where a Florida International University team tests the wind resistance on some solar panels on a small shack. The shack loses it before the panels do.