Do Solar Panels in the UK Need Cleaning?
It is often said that the rain keeps solar panels clean. Rain does wash off some loose dust, but it does not remove bird droppings, lichen, moss, pollen or the greasy film from traffic and farm dust. Over time this builds up and can reduce how much electricity your panels produce.
How much does dirt affect solar panels?
It depends on where you live and how steep your roof is. Lightly dusty panels lose only a little output, but heavy soiling, especially bird droppings and lichen that shade individual cells, can make a noticeable difference. Because the cells in a panel are connected, shading one small area can affect the whole panel.
Signs your panels need a clean
- Your generation figures are lower than the same months in previous years
- You can see bird droppings, green or yellow patches, or a grey film from the ground
- Your panels are near trees, fields, a busy road or a roof where pigeons gather
- Panels are fitted at a low angle, where dirt does not wash off easily
How often should they be cleaned?
For most homes in Kent, once a year is enough. Spring is a good time, so the panels are clean for the long summer days. Panels near trees, farmland or nesting birds may benefit from a clean twice a year.
How to clean them safely
Solar panels should never be cleaned with a pressure washer, harsh chemicals or abrasive brushes, which can damage the coating and may affect your warranty. Climbing onto the roof is also dangerous. The safest method is purified water and a soft brush on a water-fed pole, used from the ground. It leaves no residue and does not scratch the glass.
Check your warranty
Some panel manufacturers give cleaning guidance in their warranty terms. It is worth checking these, and keeping a note of when your panels were cleaned.
Want your solar panels cleaned?
Rise & Shine Cleaning is a family-run business covering Sevenoaks, Tonbridge and Tunbridge Wells. Call 07903 912285 or ask for a free quote.
Find out more about our solar panel cleaning service, or see the local pages for Sevenoaks, Tonbridge and Tunbridge Wells.
More advice: How Often Should Gutters Be Cleared in Kent?, Is Pure-Water Window Cleaning Better Than Traditional Cleaning?, How to Stop Moss Coming Back on Your Driveway or Patio. Back to all advice articles.