Why Warranty Terms Matter Before You Pick Up a Squeegee

Solar panels are one of the most dependable investments a South West home or business can make. With the region enjoying some of the best sunlight hours in the UK, systems in Cornwall, Devon, Somerset, Dorset and Gloucestershire often outperform national averages. But that performance depends on panels staying clean — and how you clean them can quietly affect the very warranty that protects your investment.

Many homeowners assume a warranty covers everything short of a lightning strike. In reality, manufacturer terms usually include maintenance conditions, and breaking them can leave you footing the bill for repairs that would otherwise cost you nothing.

What a Typical Panel Warranty Actually Covers

Solar installations normally come with two separate warranties, and it helps to know the difference.

• Product warranty: covers manufacturing defects in the panels themselves, typically running for 10 to 15 years.
• Performance warranty: guarantees the panel will still produce a set percentage of its original output after 25 years, usually around 80 to 85 per cent.

Alongside these, your installer may offer a workmanship warranty covering the mounting, wiring and roof seals, often for 5 to 10 years. Each has its own conditions, and cleaning sits within them more often than people expect.

Maintenance Conditions Hidden in the Small Print

Read the documentation that came with your system and you will usually find maintenance clauses. They are rarely dramatic, but they matter.

• Reasonable care: panels must be kept free of debris, bird droppings and heavy soiling that could cause hot spots or permanent damage.
• Approved methods: some manufacturers specify that cleaning should use soft brushes, deionised water or pH-neutral products only.
• Qualified access: working at height or walking on the roof may need to be carried out by a competent person, and some warranties state that improper access voids cover.
• Record keeping: a few manufacturers ask for evidence of routine maintenance if you make a claim.

None of this is designed to catch you out — it is there to ensure panels are not damaged by good intentions. A pressure washer aimed at the edge seals, for instance, is a common cause of water ingress that a manufacturer will quite reasonably refuse to cover.

Cleaning Products: What's Safe and What Isn't

The safest approach is almost always the simplest. Warm water, a soft brush with an extending pole, and a gentle rinse will handle most of what the South West throws at your array.

Avoid anything abrasive or aggressive. Household glass cleaners, bleach-based sprays, solvents and acidic descalers can degrade the anti-reflective coating on the glass or attack the frame anodising. Even washing-up liquid leaves a film that attracts dust, which means you will be back up the ladder sooner.

If you live in a hard water area, tap water can leave chalky spots that bake on in summer. A final rinse with filtered or deionised water solves this neatly. Many professional cleaners in the region now carry their own purified water supply for exactly this reason.

Timing matters too. Clean on a cool, overcast morning rather than in direct midday sun. Panels heat up quickly, and cold water on hot glass can cause thermal stress. Early starts also mean dew has often loosened the dirt already.

Local Challenges Across the South West

Our corner of the country has its own quirks, and they shape how often a system needs attention.

• Coastal salt: properties within a few miles of the coast in Cornwall, Devon and Dorset collect a salty film that reduces output steadily. These systems often benefit from cleaning two or three times a year.
• Agricultural dust: inland Somerset and parts of Wiltshire see fine soil and slurry particles drifting onto roofs, which cling stubbornly.
• Pollen and sap: spring brings a yellow-green coating from nearby trees, particularly in wooded valleys.
• Seagulls: coastal towns know this one well. Droppings are corrosive and should be removed promptly rather than left until the next scheduled visit.

Knowing your local conditions helps you set a sensible cleaning schedule rather than guessing at one.

Protecting Your Cover: Practical Habits That Help

A little organisation goes a long way if you ever need to make a claim.

• Keep a simple log of when panels were cleaned and by whom, with photographs before and after.
• Retain receipts if you use a professional service, and check they carry insurance and work to manufacturer guidance.
• Note any damage immediately — cracked glass, loose frames or damaged cabling — and report it to your installer before cleaning further.
• Check whether your home insurance or the installer's workmanship warranty adds anything beyond the manufacturer's terms.

If you are unsure about a specific clause, a quick call to your installer or the manufacturer's support line is worth far more than a guess. Most are happy to clarify what is permitted.

Ultimately, cleaning your panels properly is not just about squeezing out a few extra kilowatt hours. It is about keeping a twenty-five-year promise intact, and that is a worthwhile habit for any South West home or business.