Solar Panels certainly do work on cloudy days, in fact, they will work in almost any weather so long as the sun is still shining behind the clouds.
Now, that probably seems a little counter intuitive in terms of what the public thinks, but we can assure you it’s true. And now we’ll tell you why!
How does a solar panel work?
As a very famous actor from the 90s once said, ‘Here comes the science!’
One of the most popular misconceptions about solar is that you need direct sunlight to create electricity, but you just need light!
Inside solar panels are lots of PV solar cells, these cells are usually made of the Earth’s second most abundant element, Silicon.
Silicon is the cheapest and easiest material to use, currently, but other materials are coming into the industry.
Anyway, light particles, called photons, hit the silicon and cause the electrons inside the silicon’s atoms to move from a positive to a negative place.
That is very simplified to avoid a confusing, in depth Brian Cox type explanation about nuclear physics.
All we need to know is the process generates electricity, which is carried across the cell, through the connecting wires and into your home.
This process can happen with any light but it’s the strength of that light that matter.
Panels will work in rain, shine, snow, clouds and even, in a very small degree, artificial light.
Learn more about how solar panels work.
What happens to solar panels on cloudy days?
They produce loads of electricity, that’s what!
Obviously, they don’t produce quite as much as they would in normal sunshine, but they aren’t going to switch off.
You’ll notice we said ‘normal sunshine’ there, and that’s because incredibly intense sunshine will actually reduce the amount of electricity you get.
If you heat silicon past a certain temperature, its resistance will increase.
Increasing its resistance will make it harder for the electricity to travel through the circuits and that will reduce the yield of your panel.
So, a few clouds may actually be beneficial.
As it happens, the UK is pretty well positioned in the world to it avoid super intense sunshine, so your panels will be working great all year round.
The ‘Edge of Cloud’ effect.
Another benefit of cloudy weather, although very fleeting, is the ‘Edge of Cloud’ effect.
As the sun starts to come out from behind a cloud, the light from it intensifies due to being a combination of direct sunlight and the light reflected off the water droplets in the cloud.
Actually, calling it a benefit may be a bit over the top as it only lasts for a matter of minutes but, still, it is an advantage.
What about when it rains?
Rain is good, some of the time.
Your panels will still be producing electricity when it rains, even if it’s hammering it down.
The yield you get will be a lot less than on a sunny day but then light will still be getting through the clouds to jiggle that silicon.
The other plus of the rain is, it flows over your panels and keeps them clear of dust and debris.
Do solar panels work at night?
Sadly, they do not but that’s not to say they never will!
The obvious problem of the night-time is there is no sun, so you’d think that was a cut and dried ‘No’ to generate power after dusk.
But boffins all over the world are beavering away in labs to find a way to harvest the sun rays that reflect off the moon!
Yep, ‘moon’ panels are in development, but they are very, very experimental as the rays the moon reflects are so weak, so they hardly excite the silicon at all.
How do I get power when it’s really cloudy or night-time?
When your panels aren’t kicking out 1000s of watts of power for you, that’s when you start to rely on your batteries!
Adding battery storage to a solar system is such a brilliant idea we are surprised when some people don’t bother.
You can get batteries for as little as £500 and fill them up with power when the daylight is beaming down on your home.
Then, when the sun vanishes for the night, the batteries will kick in and power your home.
Some energy suppliers will even offer a cheap, overnight rate that is perfect for keeping your batteries charged.