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.
When planning your installation, just talk to your installer about your concerns and ask what they do to ensure the solar panels stay in place even in high winds. Any worries you still have should be put to rest after that.
Have them check your roof and assess whether you might need an upgrade there.
Then, ask about warranties and repair procedures in case any are needed.
2) Flying Debris Hits Your Solar Panels
The third area of concern is flying debris. Notice how we’re decreasing the severity as we go. At this point in the countdown, your roof is still there, and your panels haven’t blown off – neither of which is likely to happen even in a category 5 hurricane.
But tree branches, bottle caps, and other debris will most certainly impact your panels during a big storm. How will they hold up?
Solar panels are also tested for durability, and they can hold up to some pretty severe impacts. There’s another well-known video you can dig up yourself where a tester drives a car over their panels and fires huge ice balls at them, to mimic an impact from hail stones. The panels survive it all.
Again, there are no guarantees, and if a portion of your solar array does get damaged, you’ll be able to get it repaired. But because they need to endure weather in order to function, solar panels are designed to withstand high-impact collisions with small objects.
Same step as before: Just ask your installer and see what their repair and warranty policies are.
1) Hurricane Power Outages – Do My Solar Panels Still Work?
Lastly, the most common scenario. Your panels are still there, and they’ve withstood damage from flying debris. But, the power goes out across your neighborhood. What happens to you?
This is the surprising truth most people don’t know about solar panels. Even in the day, they will not work during a power outage.
“Why not? If the sun is shining, isn’t that all we need?”
The issue here is on-grid compared to off-grid. If your panels are off the grid, then yes, they actually should still work in a power outage. But most people don’t have off-grid