Do Solar Panels Work on Cloudy Days? What About at Night?

Do Solar Panels Work on Cloudy Days? What About at Night?

Here’s what we’ll cover in this guide:

  • How solar panels change in efficiency on cloudy days
  • Whether solar panels work at night
  • How to store solar energy for use when your panels aren’t producing
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Solar Panel Performance on Cloudy Days

Photovoltaic (PV) solar panels can use both direct and indirect sunlight to generate electrical power. This means they can still be productive even when there is cloud coverage. With that said, solar panels are most efficient and productive when they are soaking up direct sunlight on sunny days.

While solar panels still work even when the light is reflected or partially obstructed by clouds, their energy production capacity will be diminished. On average, solar panels will generate 10 to 25% of their normal power output on days with heavy cloud coverage.

With clouds usually comes rain, and here’s a fact that might surprise you: Rain actually helps solar panels work more effectively. That’s because rain washes away any dirt or dust that has gathered on your panels so that they can more efficiently absorb sunlight.

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SunPower

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  • Most efficient panels on the market
  • National coverage
  • Cradle to Cradle sustainability certification
  • Great warranty coverage

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  • Expensive
  • Customer service varies by local dealer
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Blue Raven Solar

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  • Industry-leading in-house financing
  • Competitive pricing
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  • Doesn't offer solar batteries (coming 2022)
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ADT Solar

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  • Industry-leading warranty coverage
  • Expansive service area

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  • Some reported communication issues
  • No leases or PPAs

Solar Panel Performance at Night

While solar panels can still function on cloudy days, they cannot work at night. The reason for this is simple: Solar panels work because of a scientific principle called the photovoltaic effect, wherein solar cells are activated by sunlight, generating electrical current.

Without light, the photovoltaic effect cannot be triggered, and no electric power can be generated. One way to tell if your panels are still producing energy is to look at public lights. As a general rule of thumb, if street lamps or other lights are turned off — whether on cloudy days or in the evening — your solar panels will be producing energy.

If they’re illuminated, it’s likely too dark out for your solar panel system to work.

You can get started with a free, no-obligation quote from a leading solar company in your area by clicking below.

Storing Solar Energy to Use on Cloudy Days and at Night

During hours of peak sunlight, your solar panels may actually generate more power than you need. This surplus power can be used to provide extra electricity on cloudy days or at night. But how do you store this energy for future use?

There are a couple of options to consider: You can store surplus energy in a solar battery.  When you add a solar battery to your residential solar installation, any excess electricity can be collected and used during hours of suboptimal sun exposure, including nighttime hours and during exceptionally cloudy weather.

Batteries may allow you to run your solar PV system all day long, though there are some drawbacks of battery storage to be aware of:

  • It’s one more thing you need to install.
  • It adds to the total cost of your solar system.
  • Batteries will take up a bit of space.
  • You will likely need multiple batteries if you want electricity for more than a handful of hours. For example, Tesla solar installations require two Powerwall batteries if your system is over 13 kilowatts.

You can use a net metering program.  Net metering programs enable you to transmit any excess power your system produces into your municipal electric grid, receiving credits from your utility company.

Those credits can be cashed in to offset any electrical costs you incur on overcast days or at night, when you cannot power your home with solar energy alone.  Net metering can ultimately be a cost-effective option and can significantly lower your electricity bills, but there are a few drawbacks to consider, including:

  • You may not always break even.
  • In some cases, you may still owe some money to your utility provider.
  • Net metering programs are not offered in all areas and by all utility companies.

Is Residential Solar Right for You?

Now that you know solar panels can work even when the sun isn’t directly shining and that there are ways to store your energy for times your panels aren’t producing electricity, you may be more interested in installing your own system.

You can get started with a free, no-obligation quote from a leading solar company in your area by clicking below.

FAQs: Do Solar Panels Work on Cloudy Days?

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Josh Hurst
Article author
Writer and editor with more than a decade’s experience in journalism. Josh worked for Christianity Today for seven years, and has contributed to special assignments for Apple Music and iTunes. Josh lives in Knoxville, Tennessee with his wife, Kati, and two sons, Henry and Dylan.