Do Solar Panels Work On Cloudy Days?

There are a lot of confused individuals out there who want to know whether solar panels can work despite the sometimes dreary English weather. Rest assured: a huge amount of sunlight hits the UK every day – and solar panels can use this sunlight to generate electricity.

It might not feel like it on a cold November morning, but solar energy is hurtling through unimaginable distances of space and bombarding little old England every moment of every day. Those that say England isn’t sunny enough for solar energy are missing the evidence that is all around them – all life on the planet comes from the sun, and if England gets enough sunlight to grow vast forests and extensive ecosystems then it certainly gets enough sunlight to power your home!

How do solar panels work?

In the simplest possible terms, solar panels work by allowing photons (particles of light) to knock electrons free from atoms, which generates electricity. Then an electric field, some conductive materials and a couple of other components which make up a photovoltaic (PV) cell allow the newly generated electricity to flow like any other electrical source.

A rooftop solar panel is made up of many PV cells, which is why you’ll sometimes hear solar panels referred to as solar PV. This newly generated electricity can then be used to power your home, and excess electricity can be exported to the national grid.

You might have noticed that heat is not an inherent part of this process. In fact, solar panels actually work better in cooler climates because extreme heat can interfere with a solar panel’s efficiency. So the UK’s cool temperature is, if anything, an advantage to solar panel efficiency.

So how effective are solar panels on cloudy days?

Clouds do magnify, scatter, absorb and reflect photons. Less photons hit the solar panels on cloudy days, which usually means that less electricity is generated, though there is an exception which we’ll discuss later on. Clouds don’t block out all photons — otherwise we would be in pitch darkness every time a cloud passed overhead — so solar panels do continue to generate some electricity even on cloudy days. The amount of electricity generated will depend on several factors such as the density of the cloud and the model and positioning of the solar panel.

Rather than looking at the amount of electricity that a solar panel will generate on a single cloudy day, it is more useful to estimate how much electricity a solar panel will generate during an average year. The South West and South East of England get more sunlight on average than the rest of the UK, making counties like Somerset, Kent and Essex excellent places to get solar panels installed. Talk to a solar panel installer in Essex or your local area to get an accurate estimate on the amount of sunlight that your home will get in a year — also known as your ‘insolation rating.’

Every cloud has a magnifying lining…

As we mentioned above, clouds do sometimes reflect photons, but sometimes they can magnify them too. When sunlight passes through the edge of a cloud, this can magnify the sunlight and boost to your solar panel output. These temporary boosts can help to compensate for the times when there is total cloud cover. This phenomenon is called the edge of cloud effect, and it truly demonstrates that every cloud has a silver lining.

Complete Renewables are the #1 renewable energy developers and PV solar panel installers in Essex. Send us over an email at and we’ll answer any questions that you might have about commercial or domestic solar panels, solar energy or anything else!