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Do solar panels work in the winter?

5 min read

When the days start to get shorter and the weather turns gray with heavy snow, you may find yourself wondering “Do solar panels work in the winter?” After all, fewer daylight hours, cloudier skies, and lower temperatures mean less sunlight for your panels to convert into electricity. Does that make solar panels a summer-only energy solution?

Well, we've got good news: if you choose to buy solar panels, they can be an effective and sustainable alternative to traditional power. That remains true in spring, summer, autumn, and yes, even the winter months. Here’s why.

Sometimes colder is better

Regardless of which agreement type you sign (solar PPA, solar lease, solar purchase, or solar loan), there are a lot of concerns surrounding winter-time solar use. And while reduced sunlight is probably at the top of that list, many people wonder whether low temperatures might also have a negative impact on the panel's solar energy production.

So, do solar panels work in the winter? Yes!

The truth is that colder temperatures are actually better for solar panel output. Electricity flows better when the mercury drops. And without the dangers associated with overheating, the panel systems themselves are free to function at peak efficiency. At the same time, for areas where heavy snow is a fact of life, the white drifts can reflect additional light onto the roof top panels, improving overall performance.

That said, when the snow starts to pile up on your roof and cover your solar panels, that’s when things become more complicated. If no light can get through, then no electricity flows. Fortunately, solar panels usually sit on the roof at an angle and are installed facing maximum sun exposure. That means that once the storm passes and the sun comes out, there’s a good chance that the snow will just melt and slide off on its own. Just be aware that once it does, it will need a place to land; make sure nothing fragile is underneath.

Still, even in snowy areas, experts suggest that the overall energy production loss associated with snow-covered panels is minimal.

OK. So the cold and the snow really aren’t that problematic. But what about reduced sunlight during the winter months?

Let the sunshine in

It’s no secret that PV performance (which refers to the photovoltaic effect that makes solar power possible) is dependent on sunlight. And during the winter, that sunlight may just not be as available. Of course, as long as at least some sun is getting through (meaning it’s not totally pitch-black outside), then your panels should be producing electricity. They just might be producing less than during the summer.

How much less? Well, it can be difficult to give any sort of exact numbers, but according to the Environmental and Energy Study Institute (EESI), partly cloudy weather may reduce solar cell efficiency by 20% or more. Add to that the fact that you’ll have fewer sunlit hours to generate electricity, and you may be wondering if solar panels are really the way to go.

But before you call it quits, be aware that (depending on your circumstances), 80% efficiency may still be enough energy production to meet your needs. And when it isn’t, there are fail-safes available to ensure that you’re still getting enough power, even when the sun isn’t shining.

We’re talking about solar storage and net metering.

Solar storage battery systems

Generating heat and light are two of the most common applications for electric power; if we could only use electricity when the sun is shining brightly, it wouldn’t do us that much good. That’s why many solar panels include built-in battery systems, called solar storage.

In the summer, when your panels are taking in large amounts of sunlight and producing more energy than you need, the excess electricity charges the batteries. Then, once winter rolls around, you can use that stored electricity to make up for the reduced output from your panels. This is a widely used solution. In fact, solar storage batteries is how many solar-users keep the power flowing at night. The batteries charge during the day and then take over once the sun goes down.

Net Metering

Batteries can be an effective solution to winter’s cloudy skies and shorter days. But if you’re concerned about not getting enough sun to keep those batteries charged, you can turn to the traditional electrical grid, with the net metering system.

Depending on if net metering is available where you live, it can work as follows. Any excess solar energy that you don’t use is sent to the power grid. Then during times when your panels aren’t producing enough electricity, you can draw energy back from the grid to cover your energy needs. Essentially, you’re sending power to the city, and the city is sending power back to you. Then, on a yearly basis, the utility company evaluates what your solar panels have provided and how much traditional electricity you have used, and either charges you or compensates you accordingly.

So, in the summer, chances are that your solar panels will produce an excess of power and electricity. That energy then goes back into your figurative pocket for winter use. In fact, you can think of net metering as just another kind of energy storage.

Solar energy: the right choice all year round

At Vivint Solar, we’re confident that we can help you find the solar solution that’s right for you. Our expert technicians will take into account all of the relevant details of your situation (including obstructions, local climate, average weather conditions, sun angles, and more), and design a custom plan to ensure that your winter — not to mention the rest of your year — is filled with bright, sustainable power.

Vivint Solar is committed to ensuring your solar success. Call now for a free quote.

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