Solar panel cleaning & maintenance

Most solar systems in Gauteng benefit from a professional clean every 6 to 12 months. Clean more often if the property is near construction, on a busy road, surrounded by trees, close to mines or industrial areas, or frequently visited by birds. Waiting until panels look dirty usually means production has already been lost.

Yes. Dust, pollen and bird droppings block sunlight from reaching the cells, so a soiled array produces less than it was designed to. One RobCon client in Midstream measured 32% higher generation after a professional clean. The exact gain depends on how dirty the panels were and how long since the last clean.

We do not recommend it. Roof work carries a real fall risk, household detergents and hard tap water leave residue and streaks, and abrasive brushes or high-pressure washers can scratch the glass and damage anti-reflective coatings — which can void your panel warranty. RobCon uses specialist soft brushes and a safe cleaning method that removes grime without damaging the panels.

Yes. RobCon Electrical is based in Pretoria East and services all of Gauteng, and also travels to Limpopo, North West, Free State and Mpumalanga for larger residential and commercial sites.

A typical residential array of 10 to 20 panels takes about one to two hours. We arrive with our own equipment, so no site water or electricity is required. Commercial sites are scheduled around your operating hours to avoid disrupting production.

RobCon Electrical is a full electrical contractor with many years of hands-on solar experience. We install, repair and maintain solar systems, so our team understands your panels, mounting rails, cabling and electrical components — not just how to wash the glass.

The correct method is a gentle one. Panels are cleaned early in the morning or late in the afternoon while the glass is cool, because cold water on hot glass can crack it. We loosen the dirt with water, work across the surface with a specialist soft brush, then rinse so nothing dries on. No abrasive pads, no household detergents and no high-pressure washers — those scratch the glass and damage the anti-reflective coating. We also check the mounting rails, clamps and visible cabling while we are up there, since a clean is the best chance to catch a problem early.

Sometimes. Single-storey homes with a low roof pitch can often be cleaned with extended water-fed poles from ground level, which is safer and quicker. Double-storey homes, steep pitches and commercial flat roofs need proper roof access and fall precautions. We assess this on arrival and use whichever method is safest for the specific roof — the price per panel stays the same either way.

Clean water and a soft brush designed for solar glass. That is genuinely it for most soiling. Dishwashing liquid, window cleaner and general household detergents leave a film that attracts dust faster than before, and hard tap water dries into mineral spotting that blocks light. Stubborn bird droppings or lichen need to be softened and lifted, never scraped. If a residue will not lift with the correct method, the panel usually has a coating or seal issue that needs looking at rather than more scrubbing.

Not properly. Rain rinses loose dust but leaves behind the bonded layer — pollen, road film, bird droppings and Highveld grime — and as it dries it can actually leave streaks and mineral deposits that shade the cells. On the Gauteng Highveld you also get long dry winters with almost no rain at all, which is exactly when soiling losses peak. Rain is a rinse, not a clean.