Solar Panels Work in the Snow in Michigan
People often ask if their solar panels will work in the snow. The answer is yes. . . some times. You can see in the photo above that the Michigan Solar Solutions office in Riverdale Michigan has some snow on the panels. I also inserted a photo of the readout from the inverter, indicating that 204.7 Watts of power is being created even with the snow on the panels.
I know what you are thinking: “You said some times. . . What did that mean?”
Okay, you caught me. Here is the real deal:
In states like Michigan, when we have short dark days in winter, and the snow comes down by the ton, there will be days where you have too thick of snow on the panels and the days are too cloudy for the sunlight to get through to the array. In those cases, even though a little bit of light gets through, it isn’t enough to turn on the system. It is often enough to start the panels to heat up however, and start to melt the snow off. Eventually, the panels will be snow free and when the cloud layer isn’t quite as opaque, the panels will start making power again.
All of this really doesn’t matter, however. These cloudy and snow covered days are taken into consideration when a solar company “sizes” an array for you. Regional weather data has been collected for decades and is available for solar array engineers, when they design your system. True some years are better than others for solar, and some are worse. But on average, if properly designed, your array will offset the expected amount of electricity despite the weather.
An interesting point to consider: A solar array in Michigan will only produce approximately 15% of the annual power over the span of the four months we call Winter (November through February.) So even if an array ends up having a heavy snow fall on it for a couple of weeks, it won’t really impact the overall annual production a significant amount.
Another interesting fact is that the best production from a solar panel, in Michigan, is in the early spring when the air is cold, the sky is clear and the sun is reflecting off of all of the surrounding snow covered surfaces. Solar panels actually perform better in the cold. For every degree Celsius the air temperature drops, the voltage goes up .46%. With the reflection from the snow, it is possible for a solar panel to produce more than it is rated for. That is because the rating reflects energy production under laboratory conditions. (I won’t bore you with those details!)
So the bottom line is that solar panels do work in the snow, given the right conditions. However, it doesn’t really matter if the engineer has done their job correctly.
Written by Troy Bracke, December 2017
Troy is a solar professional with Michigan Solar Solutions. He has been in the industry since 2015.