The short answer is yes, solar panels work on cloudy days.

Solar photovoltaic (PV) cells will still generate energy even when light is partially blocked or reflected by clouds. But there are a few things to consider when determining how much energy your panels can produce on those particularly overcast days.

DON’T SOLAR PANELS NEED DIRECT SUNLIGHT TO GENERATE ELECTRICITY?

Sunny conditions typically indicate fewer clouds in the sky, and thus less blockage between the sun and your panels. However, clouds can have a magnifying effect on sunlight thanks to their reflective properties. In some cases, this can improve the performance of your solar panels.

However, direct sunlight is much more reliable for solar energy production. While indirect sunlight on cloudy days will still generate power, direct sunlight gives you a more consistent, maximized energy output. You won’t have to rely on your utility company to power your home as long as you have a consistent energy source, which is less likely on cloudy days.

Direct sunlight also results in your panels generating more energy than you need, which will go back into the city’s grid and provide you with credit via net metering. Fortunately, you can tap into those energy credits to power your home on cloudy days when you need them most.

CLOUDY WEATHER VS. ELECTRICITY COST

Compared to bright, sunny weather, solar panels produce about 10% to 25% of their normal energy output on cloudy days. But this doesn’t mean that solar panels aren’t worth investing in.

If you live in a place that’s generally overcast with a rainy climate, installing a solar panel system is still very common. The cost of electricity in an area matters more than the amount of sunlight it sees in terms of saving money.

The top cities in the U.S. for solar are definitely sunny, but their electricity rates are what make them top choices. High rates push people to invest in solar and gain energy independence, rather than pay high costs to power their home. What’s more, it’s not too long before solar system owners break even on their investment, regardless of whether it’s sunny or cloudy.

As of 2022, the top five cloudiest cities in the U.S. are the following:

• Juneau
• Anchorage
• Astoria
• Seattle
• Portland

It’s no surprise that the cloudiest cities are in the Pacific Northwest. But even cities in the top solar state of California, such as San Francisco, experience lingering fog that hovers over the city most of the year. In spite of the fog, the city still has an overall warm climate with soft sunlight all year long. This makes it a great place for going solar.

​​WHICH SOLAR PANELS WORK BEST IN CLOUDY CONDITIONS?

The more efficient your solar panels are, the more energy they’ll produce in cloudy conditions.

The same goes for the type of PV cells that your solar panels are made of. Some solar cells are able to capture a broader range of UV light, such as red and blue wavelengths. This contributes to higher energy production in various weather conditions, including cloudy days.

SunPower solar panels are the most efficient solar panels on the market, and thus able to produce more energy than those ranked below it. Their solar cells have a backside mirror, which is a thin layer of aluminum, that bounces light photons back into solar cells that didn’t absorb them during the first go-around. Essentially, light has a second chance at absorption.

This results in an overall greater energy output, especially on cloudy days when only certain types of UV light manage to hit your panels.