In the UK, cloudy days are a regular part of life. Many people assume this means solar panels aren’t worth considering, as they believe solar panels can only work in direct sunlight. This isn’t strictly true.
How do solar panels work?
Solar panels work by absorbing solar energy (or ‘photons’), which creates an electric charge. This electric charge then passes into the house as an electric current to power your devices. You can learn more on how solar panels generate electricity from our article “how do solar panels work”.
Daylight, not sunlight.
Since any form of light is suitable (even artificial light would work to some extent), solar panels do work on cloudy days, albeit not as productively. On cloudy days, solar panels absorb not only energy from the light spectrum we can see, but also different wavelengths that can pass through thick clouds. As a rule of thumb, so long as you can cast a shadow, solar panels can work to create electricity, clouds or no.
Surprisingly, some areas in the south of England receive solar radiation levels equivalent to the likes of Spain and Germany, a country that practically led the way for the solar energy revolution.
The ‘Edge-of-Cloud’ Effect
According to uSwitch, cloudy weather cuts solar generation in half, but solar panels can sometimes have higher electricity outputs on partially cloudy days than a bright, cloudless day. This is known as the “Edge-of-Cloud Effect”, where the sunlight is magnified, resulting in a significantly higher electrical output.
Unfortunately, the Edge-of-Cloud Effect is something of a double-edged sword; having such large amounts of electricity generation has been known to blow the fuses and cut the inverter’s lifespan in the past.
Do solar panels work on cloudy days?
To conclude, yes – solar panels can and do work on cloudy days. If anyone were to tell you otherwise, you can tell them that solar panels don’t need direct sunlight to generate electricity. Naturally, they won’t produce as much electricity in cloudy conditions (unless the Edge-of-Cloud Effect occurs), but that shouldn’t put you off considering them, particularly if you live in the south.
Certain solar panels work better on cloudy days, but there are other facts to consider when choosing a solar panel, including the size, aesthetics and cost. The article ‘how much electricity will my solar panels make’ discusses this in more detail.
If you’d like to find out how much electricity you could generate from a solar installation on your roof, click here to find an installer in your local area and arrange a survey.