Will Winter Weather Affect Your Solar Power?

With 230+ sunny days and 3,700 hours of sunlight every year, Texas is one of the sunniest states in the country and one of the best states for solar panel installation. Solar panels in Texas can offset your electric bill, help the environment, and increase your property’s value. It goes without saying that Texas residents are taking advantage. The state ranks second in the nation in installed solar capacity, and 9,500+ Texans work in the solar industry. Our move toward solar is one of the biggest reasons Texas is leading the country in renewable energy.

But now we’re sitting right in the middle of winter, and a lot of people who have solar panels themselves or buy renewable solar energy from a retail electricity provider like Energy Texas are wondering if the cold temperatures affect solar panels’ ability to produce electricity. Have you wondered if cold weather affects solar panels, or do they only need sunlight to generate electricity? Let’s explore.

Do Solar Panels Work in the Winter?

Let’s answer this right off the bat — solar panels DO work in the winter! They rely on sunlight, not heat, to generate electricity. Just because it’s cold outside doesn’t matter. If the sun is shining and the sunlight is hitting the photovoltaic panels, the juice is flowing. In fact, solar panels actually work even better in colder temperatures.

The U.S. Department of Energy advises that “Solar panels tend to perform best in cold and sunny climates because heat interferes with the conversion of sunlight into electricity.”

There may be differences between manufacturers and models, but most solar panels are designed to perform optimally at a specific temperature known as a standard testing condition, or STC (77 degrees is common but refer to the spec sheets for panels you’re interested in). In general, for each degree above the STC, the panel is one percent less efficient. For each degree below, it will be one percent more efficient.

Does Cold Weather Affect Solar Panels?

To understand why solar panels work better in colder temperatures, let’s briefly review how solar panels work. Sunlight photon particles hit solar panel photovoltaic cells, putting electrons in the silicon into motion, and generating an electrical current that powers your home.

The thing about those electrons is that they’re at rest in a low-energy state in cooler temperatures. Electrons are activated and given energy by sunlight, allowing a greater voltage difference to be attained by the solar panel. This creates more energy and is why solar panels produce electricity better when it’s colder.

People in snowy areas have another bonus called the “albedo effect.” This is when snow on the ground acts like a mirror, reflecting sunlight upward toward the panels and essentially concentrating it.

But Isn’t There Less Sunlight In Winter?

The real culprit in reduced energy production during the winter months has nothing to do with temperature but rather shorter days that result in less sunlight. That alone can reduce the amount of electricity generated by solar panels by up to 50%. If it’s cloudy outside, that can further reduce electricity production by 10% to 25%.

Snow Can Also Affect Solar Panels

Snow on top of solar panels can affect their ability to generate electricity. While a dusting of snow has a negligible impact, a thick layer of snow can reduce or even stop the sun’s ultraviolet rays from reaching the solar panels. If snow accumulates, have it removed. Also, installing rooftop solar energy systems facing south at a 30-45-degree tilt will naturally keep snow from accumulating.

One of the best things about solar panels is that they don’t require much maintenance. Precipitation like rain and melting snow can clean solar panels by rinsing away dirt and dust and creating the right conditions for optimized electricity production.

Energy Texas Is Your Solar Energy Source

All in all, winter and cold weather do not stop solar panels from generating electricity. You can still be confident of the long-term return on investment from solar power systems. That’s the position we take at Energy Texas and all of our plans have renewable energy sourced straight from Texas-made wind and solar.