Typical prices by installation size
The market rate for professional solar panel cleaning in the UK is roughly £4–£8 per panel, including VAT. A standard domestic installation of 12–16 panels (4 kW system) therefore costs £60–£130 for a single visit.
Larger commercial arrays — typically 30–100 panels — are priced on a per-panel basis but often attract a small-volume discount, bringing the effective rate to £3–£6 per panel.
Some cleaners charge a minimum call-out fee of £50–£80 regardless of panel count. If you have fewer than 10 panels, it is worth confirming whether the quote is a flat fee or per-panel before booking.
Factors that push prices up
Roof pitch and access. Steeply pitched roofs, or systems that cannot be reached by a water-fed pole from ground level, require scaffolding or specialist rope-access equipment. This adds £50–£150 to the job depending on complexity.
Panel condition. Panels that have not been cleaned in more than two years, or that have heavy moss or lichen growth, take significantly longer and may be quoted at a higher rate.
Location. Cleaners in London and the South East typically charge 10–20% more than those in the Midlands or North. Rural locations with long travel distances may also carry a premium.
Is it worth the cost?
For a 4 kW system generating around 3,400 kWh annually, a 15% efficiency loss from soiling means losing roughly 510 kWh per year — worth around £170 at current electricity prices. A professional clean costing £80–£120 pays for itself in recovered output within the year.
Some cleaners include a panel condition report as part of the visit, flagging micro-cracks, loose connectors, or delamination. Identifying a fault early can prevent a much larger repair bill, adding value beyond the clean itself.
Getting value from your quote
Always get two or three quotes and compare them on a per-panel basis rather than a flat total. Ask whether the quote includes VAT, what cleaning method is used, and whether access equipment is included if needed.
Be cautious of quotes significantly below £4 per panel — the main costs are labour, travel, and equipment (purified water system). Unusually low prices often mean corners are cut on insurance, time, or cleaning quality.
Annual or repeat-booking discounts of 10–15% are common with established cleaners. If you are happy with the service, negotiating a regular schedule is usually the most cost-effective approach.