Do solar panels work in winter?

If you’re a homeowner thinking about switching to solar energy, you’ve probably asked yourself: Do solar panels work in winter? It’s a fair question—especially when our winters feel endless, with short days, grey skies, and the occasional snow flurry.  

The idea of relying on the sun for energy might seem like a stretch when you’re scraping ice off your windscreen, but solar panels are tougher than you might think, and they can absolutely keep delivering energy, even in the colder months. 

So, let’s dive into how solar panels work, what challenges winter throws at them, and how you can maximise their performance—because switching to solar isn’t just about saving you money; it’s about taking control of your energy future and building a healthier, more sustainable home. 

Solar panels don’t need heat, just light 

First, let’s address a common myth: solar panels don’t rely on heat to generate electricity—they rely on sunlight. Inside each panel are photovoltaic (PV) cells, usually made of silicon, which get to work when light particles (called photons) hit them. This kicks the electrons into action, creating an electrical current that powers your home. So, if there’s daylight, even on cloudy, cold, or rainy days, your panels are producing energy. 

This is why winter doesn’t spell disaster for solar energy. It’s not about the temperature outside; it’s about the light reaching your panels. And while winter days are shorter and often greyer, there’s still plenty of daylight to work with. In fact, in the UK, we get an average of 8 hours of daylight in winter, even if it doesn’t always feel like it. That’s more than enough for your panels to keep being productive, especially if you know how to optimise them. 

Cold weather actually helps 

While it seems odd, solar panels can generate more electricity in colder temperatures. This is because solar panels have a "temperature coefficient," which means their efficiency decreases as their temperature rises. Essentially, the hotter the panel gets, the less effectively it converts sunlight into electricity. So, on a bright, chilly day, the panels stay cooler, allowing them to run closer to their maximum efficiency. Conversely, on a hot summer day, the panels heat up significantly, reducing their output. It's similar to how electronic devices, like your phone battery, can experience reduced performance when overheated. 

So, while winter might feel like a solar panel’s worst enemy, those crisp, bright days can be a real boost. The key is making sure your panels are set up to capture as much of that winter light as possible. 

The real winter challenges 

Of course, winter isn’t all sunshine and rainbows. The biggest hurdle is the shorter days and lower sun angle, which means less sunlight overall. In summer, the sun is high in the sky, beaming down for up to 16 hours a day. In winter, it’s a different story—the sun is closer to the horizon, and daylight is squeezed into a small window of about 8 hours.  

But this dip in daylight doesn’t mean your panels stop working—they’re still saving you money and reducing your carbon footprint, even if they’re not at peak output. 

Snow can present another challenge for solar. A heavy blanket of snow can block sunlight completely, stopping your panels from working. But here’s the silver lining: light snow often melts quickly or slides off, especially if your panels are angled correctly. And once it’s gone, that melted snow can even give your panels a natural clean, washing away dirt and debris that might have built up over time. 

While it’s less common, ice can form on panels during very cold periods, especially if temperatures drop below freezing overnight. Ice can be trickier to deal with than snow because it sticks more stubbornly, but it’s not a dealbreaker. Modern panels are designed to withstand harsh weather, and a bit of sunshine or a gentle thaw will usually clear it up. 

How to get the most out of your solar panels in winter 

Winter might bring challenges, but there are plenty of ways to keep your solar panels performing at their best. Here are our top tips to maximise your energy output during the colder months: 

Point your panels south 

The sun’s path across the sky is lower and more southern in winter. That’s why we always recommend facing your solar panels southward—it gives them the best chance to soak up as much sunlight as possible throughout the day. It’s a simple rule, but it makes a significant difference. If your roof doesn’t naturally face south, don’t worry—modern mounting systems can often adjust the angle to get you as close as possible to the ideal position and east/west arrays provide a longer window for generation throughout the day. 

Clean your panels 

A clean panel is a more efficient panel, so it’s worth giving them a quick check every now and then. But in many cases, rain or melting snow will do the job for you. If you do need to clean them, use a soft cloth or sponge with water—no harsh chemicals or pressure washers, as these can damage the surface. 

Use your energy smartly 

Winter daylight hours can be short, typically from around 8 am to 4 pm. That’s your golden window for generating solar energy, so try to use your big appliances—like washing machines, dishwashers, or electric vehicle chargers—during the day. This way, you’re making the most of the free electricity your panels produce, instead of relying on the grid. If you’ve got a smart meter or energy monitor, you can even track your production in real-time to see exactly when your panels are working hardest. 

Add battery capability 

A solar battery can be a big advantage in winter. It stores any extra energy your panels generate during the day, so you can use it in the evening when the sun’s gone down. Without a battery, that surplus energy often gets sent back to the grid, and you might not get paid much for it. A battery gives you more control, helping you stay energy-independent and save even more on your bills. 

Are solar panels still worth it in winter? 

Yes, solar panels work in winter, even if their output dips. But does that mean they’re still a smart investment? Absolutely. In the UK, the average homeowner saves around £400 to £500 a year on energy bills with solar panels. Over their lifetime, you could even make a profit of up to £6,000, just be sure to use a reputable installer like 21 Degrees. Winter might slow things down, but it’s just one part of the picture—your panels are working hard for you cutting costs all year round. 

But it’s not just about the money. Solar panels are a step towards energy independence, reducing your reliance on fossil fuels and helping to create a healthier, more sustainable future. 

Ready to embrace solar energy? 

At 21 Degrees, we’re passionate about helping you harness sustainable energy, whatever the weather. If you’re driven by a deeper commitment to energy security, better health and comfort, and leaving a positive legacy, solar panels are a brilliant step forward. Whether you’re starting with a new-build or retrofitting an existing home, we’re here to guide you every step of the way.  

Contact us today to find out how we can help you design a solar system that’s built for your home, your budget, and the future. Together, we can create spaces that are energy-efficient, healthy, and truly sustainable.