Do solar panels work on cloudy days?

Yes, solar panels absolutely work on cloudy days and continue generating electricity even when the sun isn't directly visible. Cloudy weather does not mean that solar panels stop generating power, though it does reduce their energy output compared to bright, sunny conditions.

Solar panels operate by converting daylight – not just direct sunlight – into electricity through photovoltaic cells. Even on overcast days, diffused sunlight penetrates cloud cover and provides sufficient energy for panels to function.

Long-term concerns about living in areas with frequent cloudy weather are largely unfounded. Countries like Germany and the UK have widespread solar adoption despite their cloudier climates. Solar panels save UK residents thousands on their energy bills, making them a smart choice for British homeowners. We recommend speaking to our team to understand exactly how much you'd save and how much your home would generate.

Main Solar Takeaways

• Panels still work when it’s cloudy: Solar panels continue to generate energy under cloud cover, generating up to 80% of peak capacity on cloudy days
• Daylight drives solar power: Panels respond to ambient light rather than direct heat, meaning they can still function effectively in cloudy conditions
• Geographic location isn’t a barrier: Despite lower production compared to sunnier climates, solar remains a cost-effective choice in cloudier regions. 

How efficient are solar panels on cloudy days? 

Solar panels work their best on a clear, sunny day, but they still continue to produce energy when it’s cloudy. Typically, solar panels produce 10-25% of their peak capacity during heavy cloud cover and 50-80% during partly cloudy conditions.

What’s the impact of other weather conditions on solar performance?

Rain can clear dirt and debris away from panels, helping them function more efficiently long term. However, heavy rain blocks out sunlight and can reduce solar panel efficiency by 80% compared to a sunny day. On the flip side, wind can actually improve performance: A southerly wind can increase the energy solar panels produce by up to 43%. Wind can also cool down panels in warmer temperatures, increasing their efficiency.

What about when it snows? Solar panels require light, not heat, to generate power, which means that cold temperatures won’t impact their performance – in fact, they actually work more efficiently in cooler temperatures. Due to the Albedo Effect, snow's highly reflective properties can actually increase the amount of light that reaches your panels, boosting production. Snow can temporarily decrease power production if it falls on the panels, but most systems are installed at an angle and thus will shed snow quickly.

Solar Panels and Daylight: Why Cloudy Weather Isn't a Deal-Breaker

How Solar Panels Actually Work

Solar panels operate through photovoltaic cells that convert light energy into electricity. When photons from daylight hit the silicon cells within a solar panel, they knock electrons loose, creating an electrical current. This process happens whenever there's ambient light present, regardless of whether the sun is directly visible or hidden behind clouds.

The crucial point here is that solar panels respond to daylight, not just direct sunlight. Even on overcast days, diffused sunlight penetrates cloud cover and provides sufficient energy for solar panels to generate electricity. While the intensity may be reduced compared to days with brilliant sunshine, the panels continue working effectively throughout daylight hours.

Energy Benefits for Homeowners

By converting sunlight into usable energy, solar panels can help homeowners be more independent of the grid and save thousands on their energy bills. With their own supply of renewable energy, homeowners are also protected from future energy price increases. Homeowners with solar panels could save over £1000 a year on their energy bills – MakeMyHouseGreen customers save an average of £126 a month. 

Moreover, modern solar installations often generate excess electricity during peak daylight hours, which can be fed back into the grid or stored in battery systems. This means homeowners can use the energy they’ve previously generated even when panels aren’t working at maximum capacity, such as during cloudy periods or at night. They can also sell excess energy back to the National Grid under the Smart Export Guarantee, getting paid for what they’ve produced and don’t use.

Performance Differences: Sunny vs. Cloudy Climates

Solar panels do perform better in consistently sunny climates versus cloudier regions, but the differences are often less dramatic than expected.

A solar installation in southern Spain might generate 30-40% more electricity than an identical system in northern England. However, that doesn’t translate directly into performance. Spain's intense heat can actually reduce solar panel efficiency, as panels perform better in cooler temperatures. The UK's higher electricity rates also mean that people save more from solar per kWh generated. Finally, the UK actually gets the same amount of solar energy as certain areas of France or Spain, meaning the differences between the countries aren’t as significant as could be expected.

For those reasons, residents of cloudier regions of the UK still enjoy significant savings and environmental benefits from solar. The technology has advanced to the point where solar panels are a viable investment regardless of climate. 

Conclusion

Since solar panels are economically viable regardless of region, residents of the UK can still benefit greatly from solar installations.

When choosing a UK solar installer, it’s important to select a company with high quality equipment, good reviews, and appropriate accreditation. Reputable installers like MakeMyHouseGreen will hold MCS (Microgeneration Certification Scheme) certification, which is mandatory for accessing government incentives like the Smart Export Guarantee. Equipment should also come with extended warranties – MakeMyHouseGreen’s panels come with a warranty of at least 25 years. 

To find out exactly how much power solar panels on your roof would generate and to see how much you’d save, check out our interactive solar calculator. Our team is also happy to answer any questions about energy production in your region or about solar performance in general!