Winter

Solar Panels and What To Do About Snow

People often ask me what they need to do when it snows on their solar panels. You have two options: one is easy, but the other more rewarding.

Your first option is to do nothing. If daytime temps are in the 20's and 30's, sun and warmth will eventually melt the snow and cause it to slide off the solar array. This happens most quickly if the panels are on a steeper roof facing south, but even so, snow will eventually melt on panels with a low pitch facing east and west. And regardless of snow, solar panel systems produce the least energy during the colder months when the sun is lower in the sky and we have fewer sunny days. So if you're losing power because of snow on your panels, you're likely losing only a few percent of your overall annual output.

Your other option is snow removal. This is a good choice for people who enjoy being outdoors during the winter and also want to get the most out of their solar panels. While there are many dangerous ways to remove snow from a roof-top solar array, there are a couple of methods that are much safer and can even be fun.

Removal Option 1: hose down the array after a snowfall. Cold water will melt the snow away fairly quickly, but you'll want to use this option only when the air temperature is at least a few degrees above freezing (32F+). Otherwise you'll be doing more damage than good - and also adding an incredible amount of weight to your already heavy-laden roof. If you want to try this method, start first by tackling a lighter snowfall that leaves only a thin layer on the array, then move up to heavier snow falls as you gain some experience.

Removal Option 2: mechanical removal. Do a Google image search and you'll find there are many tools that people employ in this endeavor. But the best is probably a roof rake on a telescoping pole, like this one and this one.

Using a telescoping handle with a broom or squeegee head can also work, but they may be less efficient at grabbing the snow. If you go with the roof rake, just make sure the head is made of a material that won't scratch the panel glass - plastic and foam are good, but you'll want to stay away from all types of metal. You might not be able to reach the highest parts of your array, but clearing the snow from the bottom will give the snow at the top a clear path to slide down. And don't sweat it if there is a bit of snow remaining on the panels when you've finished raking - the last bits will melt soon enough, and the panels don't need to be 100% clean to produce power.

I hope you found this helpful. And whatever you do, don't get on the roof with a shovel.