Start with a risk assessment, not a ladder

Solar panels across the South West work hard. They face coastal salt spray in Cornwall and Devon, pollen from moorland and farmland, dust from quarrying and construction, and the inevitable bird droppings. Dirty panels can lose a noticeable slice of their output, so cleaning makes sense. But before you reach for a bucket, remember that any rooftop job is working at height. Falls from roofs, ladders and scaffolding are among the most serious accidents in the UK. A simple plan keeps you safe and your array intact.

Assess your roof, access and the weather

Every roof is different. In the South West you will find slate, clay tiles, concrete tiles, and the occasional thatch or metal sheet. Check the pitch, the height, and whether the surface is fragile. A steep roof or one with skylights, valleys, or a loose ridge tile needs professional access. Look at how you will get up there – and more importantly, how you will get down. Ladders are fine for a quick visual check from ground level, but they are not a stable platform for cleaning. Scaffolding, a mobile tower, or a water-fed pole from the ground are far safer choices. Weather matters too. Work only in dry, calm conditions. Rain makes surfaces slippery and does not clean panels effectively. Frost, dew, and strong gusts are all reasons to wait. Early morning after the dew has dried is often ideal.

Choose stable equipment and safe access

• Water-fed pole: lets you clean from the ground, keeping your feet on solid paving or grass. Choose a soft brush and filtered water to avoid streaks.
• Scaffolding or mobile tower: essential for steep, fragile, or high roofs. It must be erected by a competent person and inspected before use.
• Harness and anchor point: if you must go on the roof, wear a full-body harness clipped to a tested anchor. Never tie off to a chimney, gutter, or vent pipe.
• Footwear and gloves: non-slip soles, cut-resistant gloves, and eye protection. Wet panels are slippery even when they look clean.
• No makeshift platforms: never stand on wheelie bins, garden furniture, or the top rungs of a ladder. Never overreach.

For businesses with large arrays, a planned maintenance schedule with trained technicians is usually cheaper and safer than ad-hoc cleaning. If you manage a rural property in Devon or Somerset with a long driveway and a complex roof, get a professional access survey first.

Respect the electrical side of solar

Solar panels generate direct current (DC) whenever light hits them – even on a cloudy day. That means they are live during cleaning. Never spray water directly at junction boxes, inverters, isolators, or exposed cables. Use a gentle flow from a soft brush, and keep water away from any electrical connections. If your system has a safe isolation procedure, follow the manufacturer's instructions exactly. Many domestic systems do not have an array-level isolator that makes the panels safe, so treat every panel as live. In the South West, storms and salt air can damage cable insulation. If you see frayed wires, scorch marks, or a cracked panel, stop and call a qualified solar electrician. Do not try to clean around a fault.

Cleaning methods that protect panels and people

Start early on a dry, mild day. Work from the ground with a water-fed pole wherever possible, moving along the array in a steady rhythm. Use soft bristles – never abrasive pads, scourers, or pressure washers. Pressure washers can crack glass, force water past seals, and strip anti-reflective coatings. They also create a powerful recoil that can knock you off balance. Rinse with clean, low-mineral water. Avoid cleaning when panels are hot; thermal shock from cold water can crack them. For ground-mounted arrays, the job is easier, but still watch for wet grass, sloping ground, and trailing hoses. Coastal homes in Cornwall and Devon may need a rinse every few months to remove salt, which is harmless to panels but reduces output. Inland, pollen and dust are the main issues. A soft brush and plain water are usually enough.

Know when to stop and call a professional

Some jobs are not for a DIY approach. If your roof is steep, fragile, or higher than a single storey, or if it has skylights, chimneys, or complex valleys, call a professional. The same applies to business premises with multiple arrays, flat roofs without edge protection, or any sign of electrical damage. Professional cleaners have insurance, harnesses, and the knowledge to isolate safely. They also know the local risks – seagulls in coastal towns, moorland dust in Exmoor and Dartmoor, and agricultural debris in rural Wiltshire. If you feel unsteady on a ladder, that is a clear stop signal. No panel is worth a fall.

You do not need to clean constantly. Check your panels from ground level every few weeks. Look for broken glass, hot spots, bird nests, or debris. Trim overhanging branches. After a storm, check for damage and loose cables. Keep gutters clear so water does not back up under the array. For businesses, log cleaning dates and note any changes in performance. A clean panel is a safe panel, but the best cleaning job is one that ends with you back on solid ground.