Do Solar Panels Generate Enough Power on Cloudy Days?

June 8, 2021

Home Solar Panels Cloudy Day

It’s true, solar panels can produce less power on cloudy days, as you might expect, and yet photovoltaic (PV) solar energy use is extremely popular and an effective source of power in cities that get lots of inclement weather, like New York, San Francisco and Seattle.


Part of the answer is that clouds are not really the obstacle they appear to be. Many people think solar panels work best in sun-blasted regions with few or no clouds. That’s not quite true. Solar panels produce energy by converting sunlight to direct current (DC) and then an inverter turns that into alternating current (AC), which is the type of power most houses run on. Cloudy days create an estimated power drop-off of about 10 to 25 percent from what you see on a sunny day. But weather is fickle. Sometimes clouds can actually enhance the performance of solar panels at times by reflecting or magnifying sunlight.

More importantly, even conventional solar panels generate power with the sunlight filtering through a cloudy sky, and SunPower’s high-efficiency panels really shine at those times.

When the weather gets really wicked, like, knock-out-the-grid wicked, a solar battery system can provide timely backup power for your home. But even when the grid’s humming along just fine, energy storage allows homeowners to store solar during the day and use it when needed.

Economic factors, not just weather patterns and SunPower technology, help explain why people in cloudy regions love solar power. The biggest driver of solar power’s popularity in any region is the cost of electricity, not the amount of sunlight that area sees. That’s why many of the biggest U.S. solar cities are famously un-sunny places. The same is true of solar countries. For instance, Germany and South Korea, countries with plenty of cold, wintry weather, are two of the biggest adopters of solar.

Qualified solar installers know how to design your system to minimize any shading issues, whether it from clouds or nearby trees. We’ve created a strong dealer network with expertise in your community's weather and installation rules to tailor your home’s PV solar system for maximum efficiency. That network includes Master Dealers, a select group of installers with close ties to their communities.

Find your family’s place in the sun at SunPower’s website or by calling 1-800-SUNPOWER.