The answer is: yes!
We get this question a lot, and the truth is that solar photovoltaic modules perform better when they are cold. We had one of our customers call us last year, saying that her 5-kilowatt system was producing 5300 watts of power and it was the middle of winter. She thought something was wrong with her PV system. We assured her that she was simply taking advantage of Colorado’s intense sunshine during a cold time of the year.
Solar panels come out of the factory rated for a certain amount of energy production (in kilowatts). The energy production rating is determined using a “flash test” at standard operating conditions. This is a test in which a light shines at the panels at 1000 watts per square meter (the intensity of sunshine). The panel temperature during this test is 25 degrees Celsius (77 degrees Fahrenheit).
During the winter, there are less peak sun hours per day, but the panels are operating in colder temperatures, allowing them to work more efficiently. On days that it snows, the snow melts very quickly because most modules are installed facing the south, thus getting the most sun exposure; and they are angled, so the snow often just slides off. Yes, a heavy snow will stop energy production, but we have found that if there is a little accumulation of snow overnight, it will have melted by the peak sun hours. For those of you that have a ground mount solar pv system, you can wipe off the snow yourself, but for rooftop pv systems, this is not advised.
Another interesting phenomenon is increased output during days with many cumulus clouds. This is known as the edge of cloud effect; when a cloud begins to cover up the sun, or the sun is coming out from a cloud, the sunlight is concentrated and the output of your solar panels increases.
If you are considering getting a solar PV system, but have some questions, leave us a comment below. If you’d like your home assessed for a solar PV system, click here to schedule a site assessment where we will get on your roof and discuss your options with you.