Thinking of installing solar? A question we frequently get asked at SolarTherm UK is
‘Do solar panels stop working in a heatwave?’
At SolarTherm UK we like to debunk the myths and give you the facts – no fuss, no hiding, just honest, expert advice. We don’t shy away from the difficult questions. This article will explain the temperatures solar panels can withstand, the ideal temperatures and which months of the year you’ll see your panels produce the most solar energy.
Do Solar Panels Work in a Heatwave?
In short, yes. Solar panels are built to withstand temperatures up to 85°C, they do lose a small amount of their efficiency for every degree they go over 25°C, but the loss is negligible compared to days when it is heavy cloud or if your panels experience shading. Even at 40° your solar panels will still operate at 95% efficiency, compared to just 33% efficiency on a heavy cloud day. Most modern solar panels have an operating temperature between -40°C and 85°C, which is very unlikely to be met in the UK.
Are There Any Electrical Dangers When Solar Panels Overheat?
Theoretically, it is possible that high temperatures could cause solar panels to malfunction and start a fire, but there’s no clear evidence to suggest this has happened in the UK. A study in 2018 found that fires in the UK that had involved solar PV panels were caused by faulty equipment or poor installation.
In practice, it seems the main electrical consequence of your solar panels overheating is a drop in efficiency.
What’s the Ideal Temperature for a Solar Panel?
Solar panels work best on a clear sunny day that is between 1°C and 20°C. Temperatures above 25°C will see a slight decrease in generation but as mentioned above it is negligible when compared to a heavy cloud day.
When’s the Best Time of Year for Solar Panels?
In the UK, May to July sees the highest levels of solar generation. Long days with clear skies contribute to the optimal conditions for solar energy. However, a south facing array will still produce 12% of your annual generation from November to January.
How to Keep Solar Panels Cool in Hot Weather
The most common way to keep solar panels cool in hot weather is to install fans or to spray them with water. This tends to only be used on large projects such as solar farms as the decreased output will be more noticeable on a larger scale solar project. On a domestic property, it is usually not worth your time, effort or expense to buys a system to cool your solar panels.
On a particularly hot day, if you are able to spray your panels with water, it can be a cheap way to cool your system and clean away any dust or debris at the same time, but avoid spraying other parts of the system such as the connecting wires as getting them wet could void your warranty.
The Bottom Line
While heat can reduce solar panel efficiency slightly, it’s not enough to prevent them from generating clean, renewable power. Solar panels are built to endure a wide range of weather conditions, making them a smart investment whether you live on the south coast or the Scottish highlands. The mainly mild weather conditions of the UK are perfect for solar installation.
Ready to Start Your Solar Journey?
Contact SolarTherm UK for a free bespoke design package, tailored for your property, usage and future energy needs. No hard sell, just honest expert advice.
Your home. Your energy. Your future.
