As ingenious as this invention is, it seems to be designed for those living in sunny parts of the planet. For the Californians and the Texans. But what about those of us living in the parts of America with snowy winters? Does it make any sense to have solar panels if they’re covered in snow? Are solar panels worthless in winter?
We answer these questions in this blog.
Do solar panels work in winter?
Short answer — yes, they do. Solar panels convert sunlight into electricity. As long as there is sunlight falling on the panels, it does not matter how hot or cold it is. In fact, photovoltaic (PV) solar panels work more efficiently when it is cold.
This is because, like all electric appliances, solar panels work more efficiently in cooler temperatures. When solar panels are being tested for their maximum output, the testing is done at a chilly 5°C (41°F). It is in these cooler temperatures that solar panel output is at its optimum.
In fact, manufacturers rate their solar panels for peak temperature. It is the temperature beyond which the efficiency of the solar panels starts decreasing. Once the temperature of the panels rises above that peak temperature, their efficiency for creating electricity decreases. In the winter, it’s less likely for solar panels to ever reach their peak temperature. Hence they are more likely to be performing at peak efficiency.
However, this increase in efficiency is offset by the fact that there are shorter days (and thus fewer hours of sunlight) during winter. This results in energy outputs during winter which are not drastically different from the outputs in summer.
A lot also depends on your geographical location from the equator. Your solar panel requirement and the savings you can make will change depending on where you are located.
So, my overcoat and woolen socks wearing friends, do not despair. Solar panels work efficiently during sunny winter days. In fact, they also help you keep your house warm by lowering the cost of your winter bills.
We all know how heating systems drain electricity and result in exorbitant bills during winters. Having solar panels can help you significantly bring down those bills.
Will energy be generated with snow on solar panels?
If your panels are covered with a thick layer of snow, then no, they will not generate energy. The good news is that snow rarely affects solar panel performance in real-world conditions. Here are the factors that minimize or altogether cancel out the negative impact of snow on solar panels:
Solar panels are usually installed at an angle, which makes it easy for the snow to slide off. You can always consider getting solar panels with either continuous panel tracking or seasonal panel tracking. With both these systems, the angle of the panels can change. By making the angle steeper during winters, one can optimize the angle of the sun rays falling on the panels and also make it harder for the snow to collect on them.
The dark solar panels attract heat and help in melting the snow. Solar panels are designed to attract the sun’s rays and trap them. Generally speaking, solar panels are 20°C (36°F) warmer than the ambient temperature. So even a glimmer of sunlight can cause the solar panels to start warming up and hence hasten the melting of snow around it.
Snow has anti-soiling properties, and hence when it melts, it takes with it any dirt on the panels. This is similar to what happens to snow covering the windscreen of your car: when it is allowed to melt off, it takes away all the dirt with it. You end up with cleaner panels working at a higher efficiency.
Snow can increase the output of your solar panels. Due to the albedo effect. The phenomena wherein a part of the sun’s light when it hits the earth’s surface is reflected back into the atmosphere. A much greater amount of sunlight is reflected back when it hits certain types of surfaces, a prime example being white, reflective snow. Solar panels surrounded by snow can end up absorbing twice the amount of light because of the albedo effect and hence increasing the energy output of the solar panels.
If you must, then you can use snow removal tools. But we recommend against it. The possible chance of injury to yourself or damage to your panels is not worth it. This solar panel roof rake seems to be specially designed for solar panels.
Overall, snow should not dramatically impact solar panels or how they work in the winter.
Consider getting snow guards for solar panels
This is applicable for places that get high amounts of snowfall. Solar panels themselves should not suffer any damage due to heavy snowfall. Any solar panel you have is meant to withstand all kinds of weather and this includes snow. Solar panels are built to last.
But it might be worth getting snow guards for your panels. Snow guards can help avoid any costly damage or injury, Why is that? Well, solar panels, unlike standard roofing material, do not offer much friction for the snow that collects on them. Hence if you have had heavy snowfall, large chunks of snow can slide off all at once from the panels. Nobody wants big chunks of snow and ice falling on their belongings, or worse yet, on their loved ones!
Snow guards are great because they’re relatively cheap, and they allow the snow to fall off gradually.
The bottom line on solar panels in winter
Solar panels are popular in some of the snowiest states. New York, Massachusetts, New Jersey, are all in the top ten destinations for solar panel installation in the country. If these states can make savings with solar, we all can.
Your electricity rates decide the value of installing solar panels, not the weather. Electricity rates are one of the most significant factors in deciding how economically viable a solar panel installation is. After all Germany, with sunshine levels that are similar to Alaska, has been a leader in solar installations for over a decade. In cities like New York, where the electricity tariffs are high, solar panels can end up being extremely profitable.
Finally, here is a short informative video from the U.S Department of Energy which explains why solar roofs work just fine in colder climates.
The weather should not dictate your decision to get solar panels. A much more important factor in how much you can save with solar panels in your location. You can get an easy estimate of that by using the solar calculation tool below.