When cleaning helps
Rain rinses a lot of loose dust off steep panels, so not every roof needs cleaning. It is worth it when you can see:
- Bird droppings, which rain rarely shifts and which shade part of a cell
- A line of dirt or lichen along the bottom edge, where water runs off and dries
- Panels on a shallow roof or a flat-roof frame, which don't self-clean well
- Homes near fields, busy roads or the coast, where dust, diesel film and salt build up
The honest test is your own inverter or app: compare a sunny day's output before and after. We would rather you check than take our word for it.
How we clean panels
Purified water has nothing left in it to dry into spots, so we don't need soap. A soft brush loosens the dirt and the pure water rinses it off. Most panel makers warn against pressure washers, harsh chemicals and abrasive pads, and we use none of them. We don't walk on panels or on the roof.
What we need to know
- Roughly how many panels, and on which side of the roof
- Whether it is a two-storey or a bungalow roof
- Whether pigeons have got under the panels (that's a proofing job, which we don't do)
A photo from the garden on WhatsApp is usually enough for us to quote.
How often should panels be cleaned?
There's no fixed rule. Steep, open roofs inland may only need an occasional clean, because rain rinses off loose dust. Panels on shallow roofs, by the coast, near fields or busy roads, or under trees and perching birds tend to need it more often. Our guide on how often to clean solar panels in the UK goes through it.
Bird droppings
Droppings matter more than dust. A dropping blocks light from part of a cell completely, and rain rarely shifts it. Because cells are wired in strings, a small shaded patch can cost more than its size suggests. Read more in do bird droppings on solar panels matter.
Panels by the sea
Homes along the Essex coast and estuary, from Canvey and Southend to Burnham and Clacton, get a salt film on their panels. Salt dries into a haze that rain doesn't clear, especially on shallow bungalow roofs. Pure water dissolves it and dries clear.
What we don't do
- We don't install, repair or test panels or inverters. That's your installer's job.
- We don't fit bird-proofing mesh. That's a specialist trade.
- We don't walk on panels or the roof, ever.
If your output has dropped and the panels look clean, speak to your installer first. Cleaning only helps when dirt is the problem.
Do you need to be home?
No. Panel cleaning is all outside. As long as we can get to the side of the house the panels are on, you don't need to be in. We'll message you when it's done, so you can check your figures on the next sunny day.