Purified water and a water-fed pole: the non-negotiables
The professional standard for solar panel cleaning is a soft-bristle brush on a water-fed pole, fed with purified (deionised or reverse-osmosis filtered) water. Purified water contains almost no dissolved minerals — typically less than 10 mg/L compared to 200–400 mg/L for mains water. It cleans the glass without leaving a mineral residue when it dries.
Any cleaner using tap water, even with a soft brush, is introducing new mineral deposits onto your panels with every rinse. Ask any prospective cleaner directly: 'Do you use purified water, and do you carry a TDS meter to verify it?' A reputable cleaner will know exactly what TDS stands for (total dissolved solids) and why it matters.
Avoid any cleaner who proposes using a pressure washer. High-pressure water can force moisture under the panel frame, damage the junction box seal, and in some cases crack solar cells if there are existing microfractures.
Insurance: what to check before you book
A professional solar panel cleaner should carry two types of insurance: public liability insurance (to cover any damage to your property during the clean) and, if they are working at height above ground level, employers’ liability insurance if they are using any employees or subcontractors.
Ask for a copy of their public liability certificate before the job starts. The cover should be at least £1 million, ideally £2 million or more. Some cleaners include cover for accidental damage to solar panels and inverters — this is worth asking about specifically.
Working on a roof at height without appropriate insurance is not just a risk to you — it means the cleaner is likely unregistered and untrained, which correlates with corners being cut elsewhere too.
Where to find reputable cleaners
Checkatrade and Rated People both list solar panel cleaners with verified reviews from previous customers. Both platforms require businesses to submit proof of insurance and carry out identity checks. Reviews on these platforms tend to be more reliable than generic Google reviews because they are tied to a completed booking.
FindSolarCleaner.co.uk is a dedicated directory for solar panel cleaning specialists — listings include verified customer reviews and cover dozens of towns across England and Scotland.
Word of mouth from neighbours who have had their panels cleaned is also a reliable source — particularly if you can see the panels afterwards and assess the finish.
Red flags to watch for
Be wary of cleaners who cannot tell you what type of water they use, quote suspiciously low prices (under £2 per panel is a signal that they are cutting corners), or cannot provide a public liability certificate on request.
Avoid anyone who offers to clean from a ladder against the panel frame rather than from a water-fed pole system. Leaning ladders against panel frames can crack the aluminium and void the structural warranty on the mounting system.
Be cautious about unsolicited doorstep offers, particularly following a storm. Cold-call solar panel cleaning operations are a known vehicle for overcharging and substandard work. Use a vetted platform or a referral from someone you trust.
What a professional clean should cost
In most parts of the UK, the typical price range for a domestic solar panel clean is £4–£8 per panel, with a minimum call-out charge of £50–£80. A standard 10–16 panel residential system should cost £60–£120 for a professional clean.
Featured cleaners on this site are verified businesses with insurance and customer reviews. Search by postcode to find someone in your area and compare prices before booking.