Professional Solar Panel Cleaning in Lancashire

Rain does not clean your panels

This is the one thing nearly everybody gets wrong. Rain runs off glass and takes the loose dust with it, but it leaves the bonded film behind and it concentrates the dirt in a line along the bottom edge of every panel, right where the frame stops the water. That dark strip you can see from the ground is soiling, and it is doing more damage to your output than the rest of the panel put together.

Lancashire gets plenty of rain and plenty of dirty panels, which tells you everything about how well rain works as a cleaning method. Typical soiling losses in the UK sit in the low single digits, but that average hides the real problem: bird mess, moss and a heavy edge line can cost far more than a few per cent, because of how panels are wired.

Why a little dirt costs a lot of output

Panels in a string are only as good as the worst one, and within a panel the cells are grouped. Shade one row of cells properly, with moss along the frame or a decent splat of bird mess, and the bypass diodes take a chunk of that panel out of the equation. The loss is out of all proportion to the area covered.

That is why an annual clean is worth doing even though the glass never looks that bad from the ground. You are not cleaning it to make it look nice. You are removing the shading.

What dirties panels across the county

It varies by where you are. On the farms and rural properties across the Fylde, the Ribble Valley and out towards Garstang it is soil dust in the dry spells, silage and muck spreading, and a lot of bird activity. Near the coast it is gull mess, which is acidic and worse if it is left to bake on through a summer.

In the Pennine towns it is moss. The panels sit on a roof that is already growing it, and the moss migrates down the tiles and onto the bottom edge of the array. In the towns along the M6, M65 and M61 it is traffic film, which is greasy and needs purified water and a soft brush to shift rather than a hose.

How we actually clean them

Purified, deionised water and a soft brush on a telescopic pole, worked from the ground. No detergents, no chemicals, no pressure washer, and nobody walks on the panels. Pure water dries without spotting because there is nothing dissolved in it to leave behind, which is the same reason it works so well on glass.

We do not use anything abrasive and we do not use anything that could get in around the seals. Panel manufacturers are clear on this in their own maintenance guidance, and it matters if you ever need to make a warranty claim. See the main solar panel cleaning page for the full method.

How often, and when

Once a year covers most domestic arrays in Lancashire. Twice for farm buildings, anything under trees, anywhere with a pigeon or gull problem, and commercial arrays where the return on the extra visit is obvious.

Late winter or early spring is the best single slot, because you are cleaning just before the months that generate the most. If you only do it once, do it in February or March rather than in October.

Moss, birds and the things that make it worse

If the roof itself is mossy, cleaning the panels alone is a short-term fix, because the moss comes straight back down onto them. It is usually worth doing the roof cleaning at the same time, and it costs less done together than as two visits.

Birds nesting under the array are the other recurring problem. It is warm, dry and sheltered under there, and once pigeons find it they stay. The mess ends up on the panels and in the gutter below. Proofing the perimeter is the fix, and the time to do it is right after a clean rather than three years of build-up later.

What it costs

Price depends on the number of panels, the height and the access. A ten panel array on a standard two storey house is a straightforward job. A farm roof with a hundred panels, or a commercial array with restricted access, is priced after we have seen it.

Tell us how many panels you have and your postcode and you will get a fixed price, usually the same day. If you are having the roof or the gutters done as well, say so, because doing it in one visit is cheaper than three.

What we look at while we are there

A clean is also the only time anyone properly looks at your array, so we tell you what we find. Cracked or clouded glass, a panel sitting proud of its rail, bird proofing that has come away, vegetation that has grown into the shading line, or a gutter under the array packed with moss. None of that costs extra to report and all of it is cheaper to deal with early.

We do not touch anything electrical. Isolators, inverters, wiring and connectors are an installer or electrician job, and if something looks wrong we will say so and leave it to them.

Questions we get asked

Will cleaning damage the panels? Not the way we do it. Pure water and a soft brush is the manufacturers own recommendation. What damages panels is pressure washing, abrasives, and people walking on them.

Will it definitely increase output? On a dirty array, yes, and the dirtier it is the bigger the difference. On an array cleaned last year it will be smaller. If your panels have never been cleaned, the gain is usually obvious on the app within a few days.

Do you need to get on the roof? No. Everything is done from the ground with poles, which is safer, quicker and means no ladders leaning against your gutters.