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Solar panel cleaning in Birmingham is worth doing less often than most people are told. The Energy Saving Trust says rain will clean panels tilted at 15 degrees or more, which covers most pitched roofs in the city. Where cleaning does pay is on panels the rain can’t keep clear: shallow and flat roofs, ground-mounted arrays, and panels under trees, beside busy roads or used as a perch by pigeons.
When panels need a clean
Look at the panels from the ground. A light film of dust is normal and the next heavy shower will shift most of it. Green moss or grey lichen creeping in from the frame edges, a crust of bird droppings or a layer of grime from a nearby road are different. They block light, and because panels in a string are linked, heavy dirt on a few panels can drag down the output of the rest.
The Energy Saving Trust notes that debris builds up more on ground-mounted panels and in areas with more dust in the air. If your generation has dropped and the panels look clean, the cause is more likely to be a fault. Solar panel repair covers that.
How we clean
Panels are cleaned with pure water, which has had its minerals taken out so it dries without streaks, and soft brushes. No pressure washers and no detergents that the panel maker doesn’t approve, because harsh cleaning can damage the glass coating and seals and affect the warranty. Moss and lichen are worked out of the frame edges by hand.
While the panels are clean, they are easy to check. Cracks, discoloured cells, loose fixings and signs of pigeons nesting underneath are noted and photographed. If birds are the problem, solar panel bird proofing stops it happening again.
What it costs
Checkatrade gives £60 to £100 to clean about 40 panels at ground level, and £150 to £300 above one storey, or around £15 a panel. The price depends mostly on access. A clean can also be done alongside a service, which checks the inverter and wiring as well.
What's included
- A look at whether cleaning is needed at all
- Pure-water clean of the whole array
- Moss and lichen removed from panel edges
- Bird droppings cleared
- Frames and visible fixings checked while clean
- Cracks, hot spots or damage noted
- Nests or pigeon activity reported
- Before and after photos
How the options compare
Panel surface
- Leave it
- Dirt builds up where rain can't reach
- Pressure washer
- Risk of damage to seals and coatings
- Pure-water clean
- Cleaned without harsh pressure or chemicals
Moss and lichen
- Leave it
- Keeps spreading
- Pressure washer
- Blasted off, with the risk
- Pure-water clean
- Removed by hand
Streaks
- Leave it
- n/a
- Pressure washer
- Tap water can leave marks
- Pure-water clean
- Pure water dries clean
Damage spotted
- Leave it
- No
- Pressure washer
- Unlikely
- Pure-water clean
- Checked while the panels are clean
