Do Solar Panels Work in Winter?
Last Updated January 31, 2024
By Michael Jones
Michael literally wrote the book on solar (it’s called The Homeowners’ Guide to Going Solar) and has been a solar consultant for over four years.
A common question I get when chatting about solar power on Cape Cod is, “Do solar panels work in winter?” It’s an understandable concern for anyone who has endured the harsh winters we often get on the Cape.
After all, a snow-covered solar array isn’t going to generate as much power as a sun-bathed one. And if you consider the fact that the sun sits lower in the sky and sets several hours earlier during winter time, it’s not unreasonable to question how useful panels will be from November through February.
But while it’s true that your solar panels are not as potent in winter compared to the summer months, they can still function effectively all year round.
Let’s break down how winter time generation and summer time generation can work together to give you solar energy all year long.
Solar Panels Work Surprisingly Well in Winter
There are two reasons why solar panels actually work surprisingly well in the winter months. One is the overall efficiency of the panels themselves, which is higher in cold temperatures than in warm ones.
In fact, most pros in the solar industry agree that when temperatures climb above 77 degrees, the solar panels can’t perform optimally without the risk of overheating. Cold winter temperatures prevent this overheating and allow the panels to operate more efficiently.
Is this increased efficiency enough to make up for the shorter days, lower sun and potential snowfall? Not really.
But there is a second factor that comes into play.
Most people mistakenly believe that solar panels only convert sunlight that comes directly from the sun into electricity. But in winter time, there are many other sources of light that can be turned into power. Snow from the ground, from the trees and even from surrounding buildings can be turned into electricity if it’s reflected onto your rooftop solar panels.
What if the Snow Covers Your Solar Panels?
Solar panels, due to their design and the angle they’re set up at, don’t usually stay snow-covered for more than a few days at a time. Interestingly enough, you might spot these panels entirely cleared off just a day or two after a heavy snowfall, even though the surrounding roof remains blanketed in white.
First off, solar panels are often installed at a fairly steep angle in order to optimize their exposure to sunlight. That, coupled with their smooth glass surface means that snow easily slides right off.
Then there is the fact that like any dark surface, solar panels absorb heat from the sun. Once even a small area is exposed, the panels start to generate power, producing a small amount of heat in the process.
As the panels soak up heat, it’s like a domino effect, leading to more of their surface getting exposed. Before you know it, the entire system is generating power and warmth at peak efficiency.
Moreover, when the snow melts off your solar setup, it gives your panels a free cleaning. So, not only does your panel spring back to life in a few days after snowfall, but it also performs better because it’s both cooler and cleaner.
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Should You Clear the Snow off Your Solar Panels?
No, you really don’t have to clear off that snow. Why? Well, your solar panels were set up with a whole year’s worth of sun in mind. So, any small drop in power from the snow is balanced out when summer rolls around.
When figuring out sun hours for power generation, the solar company will consider a full year – and yes, that includes snowy Cape Cod winters. It’s all part of the plan to make sure your energy needs are covered throughout the entire year.
In fact, your system is specifically designed to overproduce in the summer, store the excess summer production in the grid in exchange for Net Metering credits and use your stored excess to cover production shortfalls in the winter.
So climbing on a slippery roof in the middle of winter to clear snow off your solar panels is a risk that’s not worth taking. What’s more, you might void the warranty on the panels if you damage the panels while scraping that snow off.
It’s far better to just leave the snow up there and wait for it to slide off naturally. In no time at all, your solar panels will be working at full “winter” capacity which, combined with electricity from the grid, will give you all the power you need.
Final Thoughts – Do Solar Panels Work in Winter?
Although your solar panels produce less power in the winter than in the summer, that loss of production is offset somewhat by the fact that cold temperatures makes the panels more efficient, snow allows them to absorb reflected light, the panels get a free cleaning as it slides off.
In simpler terms, this system is specifically designed to produce more power than needed in the summer and store the excess for those winter months when the panels are expected to under-produce.
If the system is properly-sized and the sun-hours are accurately calculated sun hours, then it ought to be able to give you all the power you need year-round.
If you’d like an informative, no-pressure chat with either of the Cape Cod Solar Guys, you can contact us here.
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