Solar panels are a reliable source of electricity that can allow you to rely on the power grid a lot less—and, in some cases, may even allow you to be completely independent in your energy production. However, those panels on your roof do rely on the weather to produce electricity regularly. While some impacts on your energy production may be obvious, others might surprise you. Keep reading to learn how the weather impacts your solar panels’ electricity production.
Clouds and Fog
This is probably the most obvious weather to impact your solar panels. Anything that stands between your panels’ photovoltaic cells and the sun is going to impact the panels’ ability to produce electricity. However, a cloudy or foggy day doesn’t mean a complete shutdown of your panels. Just as you can still get a sunburn sometimes when it’s cloudy, some sunlight can pass through on overcast days.
An easy visual way to check if your panels are currently producing electricity on a cloudy day is to look outside and see if any objects are casting a shadow. If you can see even a faint shadow under that tree in your backyard, then your panels are likely still producing some energy. Generally speaking, your panels will produce between 10% and 30% as much electricity on cloudy days as they produce on sunny days.
Rain and Snow
Obviously, rain and snow come with clouds, so the overcast skies that come with these weather patterns will naturally drop your panels’ weather production. However, beyond the cloud coverage, rain can actually be good for your solar panels’ production levels in the long term. This is because regular rainstorms are a natural, easy way to clean off those panels and keep any dirt or grime from accumulating on the cells. Accumulated dirt blown in on the wind can decrease productivity over time, but a single rainy day can prevent that.
Snow, on the other hand, can be a problem, as it can accumulate on panels. Typically, snow will melt or slide off solar panels not long after falling due to their heat and their tilt on your roof. But as long as there’s snow on them, production will be down.
Finally, it’s important to be aware that operating temperatures also impact your panels’ productivity. Like other electronics, solar panels work more efficiently in cooler temperatures. Generally speaking, for each degree above 77 degrees Fahrenheit, efficiency will decrease by 1%. For each degree below 77, efficiency increases by 1%.
Because solar panels’ productivity can change with the weather, it’s important to have a backup power source like a Simpliphi battery bank to keep your home running when your panels can’t meet your immediate power needs.