How to make solar panels and hurricanes tolerate each other
- 27 Jan 2021
- 7 min
The typical Atlantic hurricane season lasting from 1 June to 30 November produces 12 named storms. Half of the storms become hurricanes. Half of the hurricanes are usually classified as major, with winds greater than 110 mph. While people have already got used to Mother Nature's mood swings, the first rendez-vous of solar panels and a hurricane may go off course. Here are some tips on how to help your solar system get along with any tropical cyclone.
Hey, hurricane, here's your speeding ticket
A hurricane is defined as 'a large rotating storm with high speed winds that forms over warm waters in tropical areas'.
When they say 'high speed', they really mean it. Hurricane's sustained winds are 74 mph or faster. On October 23, 2015, Hurricane Patricia's winds set a record of 215 mph. By comparison, the average highway speed limit in the USA is 70 mph.
Hurricanes use moist air rising over warm ocean waters as fuel, just like giant engines. When warm moist air rises, it is replaced by cooler air. The cooler air then warms and rises too, repeating the cycle. This causes huge storm clouds to form. They start to rotate with the spin of the Earth forming an organized system. The system of clouds and wind spins and grows, causing a hurricane to form.
Hurricanes have large spiral bands of rain called rainbands. These bands can drop big amounts of rainfall when the hurricane strikes land and cause flooding.
So, hurricanes bring about winds and rains which are, no doubt, disastrous for people and property. Solar panels are no exception, but don't think they will give up easily.
Whether the weather is windy...
When a hurricane comes, high winds blow from all directions and can wreak havoc on your solar panels. Wind passes through the small space that normally exists between the panels and the roof or the ground causing panels to lift up or come loose. Such uplifting forces might tear panels from their mounts, or even the mounts from the roof or ground. However, this is rarely the case: professional installers take all that into consideration and mount solar panels according to wind patterns. As for PV modules themselves, most of them are certified to withstand winds of up to about 140 mph.
Another source of panel damage caused by high winds can be flying debris. The materials blown around may be of different sizes and types, but solar panels are able to go through it all. On May 8, 2017, the Denver area saw an unusually severe hailstorm, which left golf ball-sized dents on the roofs of homes and cars. A large rooftop solar array of the National Renewable Energy Laboratory (NREL), however, survived with only one broken panel out of 3,000.
Or whether the weather is rainy...
A hurricane means heavy rain and flooding as well. Luckily, the aluminum and glass casings that encapsulate solar cells are highly waterproof, even during extreme rain. That allows solar panels to continue generating energy even in such conditions.
What's more, rain can be good for your solar panels. The water will wash away dust, dirt, and other airborne particles that might have built up on the modules over time. That will make them work even more efficiently than before.
Hail isn't usually a concern during a hurricane. The warm air, which forms a tropical cyclone, just melts hail before it reaches the ground. Strong winds also contribute to that: they blow hail horizontally, preventing it from falling straight down and, thus, giving it more time to melt.
Solar panels will weather any weather if you prepare them for it
Unlike rooftop systems, ground-mounted solar installations may require an additional insurance policy, since they aren't always considered a fixture.
Panels and racks are built strong enough to withstand a hurricane. So, there's no need to cover them with anything or, what's more, to remove the modules before the storm. Don't worry, solar panels won't make the roof fly off your house, unless the roof itself is willing to do so.
Here are some useful things to do well before a hurricane:
• Check if your manufacturer's warranty covers damage caused to the solar panels as a result of a hurricane.
• Contact your insurance company to find out if your insurance plan covers the solar panel system. Make sure you are eligible for the full replacement value of your solar system.
• If you lease your solar system, examine the contract to make sure adequate coverage is provided.
• Take photos of your solar panels. Later they can be used as proof of the solar system initial condition, should you need to file a claim with your insurance provider. It's a good idea to keep both hard and digital copies of the photos.
If the worst has happened, stay calm and patient
After the hurricane is over, you may want to assess the damage to your solar panels, if any. And here go our don'ts:
• Don't get on your roof.
• Don't touch any loose, damaged or displaced panels or wires.
• Don't inspect or repair damaged solar panels yourself.
All that is extremely dangerous, as the panels and wires can still be energized following the hurricane.
What you really must do is to take pictures of any sustained damage from a safe distance and notify your solar manufacturer or insurance provider. They will instruct you on further steps and send a specialist to inspect your solar panels if necessary.
Don't rush to harvest sun right after the hurricane
If there isn't any visible damage to your panels, check if your system is working. You can use an online monitoring program or inspect the inverter: a red light or lack of display during the daytime will mean that something is wrong.
Usually, it will be the local power grid that won't let your system get back to normal. With a grid-tied solar system, you will have to keep the solar array turned off until the grid is repaired after the hurricane. If you have a hybrid solar system, you can use the battery to power basic needs while still remaining disconnected from the grid. If you are an off-grid solar system owner, congrats! You can continue generating energy as if nothing had happened.
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