Solar panels are a great way to reduce your carbon footprint and knock a little off the monthly utility bills (or more than a little if you’re lucky), but do the benefits last into the winter? After all, your solar panels are going to get less direct sunlight in the colder months of the year, and sometimes they’ll be covered by snow outright.
Certainly, some of the older models of solar panels had some efficiency weaknesses that were particularly problematic in the winter, but what about the newer models?
Well, there is some good news. New solar panels are designed to maintain their efficiency even in wintry conditions, here’s how it works.
How Do Wintry Conditions Affect Solar Panels?
One of the first questions many prospective solar panel owners ask is whether the cold weather will reduce solar panel efficiency. There are three things that seem like they could reduce efficiency:
- Snow on the panels
- Cold temperatures reducing efficiency
- Reduced solar exposure
While it might make sense for all three of those conditions to affect your solar panels, the results aren’t what you expect. Here’s what each of those weather conditions does.
Snow on Your Solar Panels
Snow can impact the efficiency of your solar panels for the worse, but it’s a very temporary problem when it happens.
The first impact you’ll notice is that your solar panel performance will probably be lower when you’ve got the cover from snow clouds, even before the snow starts to fall. That’s because there isn’t as much light reaching your roof or reaching the ground, depending on what kind of solar panels you have.
Once the snow is on the ground, you’ll also have to deal with reduced performance as long as the snow is on your solar panels.
Fortunately, snow buildup on the panels is relatively uncommon.
You should also consider snow guards for solar panels.
There’s a reason that your solar panels will be installed on an angle instead of flat on the ground or flush with your roof.
Tilting the panels helps catch a little more light if you can tilt them toward your southern exposure, but it also helps to prevent snow from building up on the panels themselves. Snow will generally slide off the panels as it falls.
Heavier and wetter snow may stick, but it will still usually sheet off as the snow reaches a certain weight.
Worse comes to worst, you can brush snow off your solar panels. You will want a specific brush that’s soft enough to take the snow off the top of the solar panels without scratching the surface of the solar panels.
The only time that snow will cause more of a serious problem is if it’s deep enough to cover the solar panel so that you can’t just brush it off. Even then, the snow on top of your solar panel will likely melt faster than the snow on the rest of the ground, since the heat of the light on the solar panel (even the light that gets through the snow itself) will help to melt it faster.
Once your solar panels are uncovered you can actually get better solar efficiency when there is snow on the ground. That’s because your solar panels can take advantage of all available light, not just the light that’s coming directly from the sun.
Snow on the ground is one of the better reflectors of solar light out there. That’s why snowy days can seem so bright, they literally are brighter and can even be brighter than a sunny summer day without snow.
Your solar panels take advantage of all that extra reflected light to produce more energy.
One of the other common concerns is whether the colder temperatures will reduce efficiency themselves.
There’s good news here too. Cold temperatures are good for most electronics, and your solar panel system doesn’t rely on heat to produce electricity.
The solar panels themselves just need light to operate. While the surface of the solar panels can heat up since they tend to be darker colored and anything dark heat up in the sunlight, all that excess heat can reduce solar efficiency.
Colder temperatures improve the efficiency of energy transfer from your solar panel to the wiring that’s supporting it. You may see a bump in performance, even when there isn’t snow on the ground, just because the colder temperatures are reducing the energy lost in transfer.
Reduced Solar Exposure
The last common concern when it comes to winter efficiency is that the sunlight you get in winter months is less direct than summer sunlight. It makes sense that this less-intense form of sunlight might impact performance.
The truth is that your solar panel will produce less energy from direct sunlight, but the change in efficiency is very small, and a lot of the efficiency loss is made up by other advantages from winter conditions.
We’ve already talked about how snow on the ground and colder temperatures can improve your solar efficiency in the winter. Both help to make up for any lost energy thanks to less intense sunlight.
But the other major factor in your solar panel’s performance is the improved design of the solar panels themselves. Early solar panels were significantly less efficient than modern designs, which is why solar panels were mostly installed in sunny places and were less common through New England and the cloudy North Western coastal states of Washington and Oregon.
More modern designs have a much lower light-threshold for efficiency. Your modern solar panels are probably still producing energy under moderate cloud cover, even when it’s raining or snowing. That’s why modern solar panels are considered efficient in almost all locations. They need less sunlight, so your location and climate have less of an impact.
Those same advantages mean less energy lost in the winter, and let you make the most of winter’s efficiency advantages.
Ultimately, your solar panels will probably perform just as well in the winter as they do in the summer. Depending on where you live and how much snow you get, your solar panels may even do slightly better in the winter, despite shorter days and less direct sunlight.
Don’t worry if you live somewhere with high snow totals. Winter conditions won’t stop your solar panels from producing electricity, and you’ll still see the benefits on your monthly utility bills.