Dover Heights has good sun and unobstructed roofs, which makes it good solar country. It also has salt spray and seabirds, which make panels dirty faster than in sheltered suburbs.
Solar panel cleaning is searched around 590 times a month in Sydney, peaking at about 720 in October. On the coast, the reason is usually salt.
What dirties coastal panels
Salt film. Builds as a haze across the glass, particularly in dry months when rain does not rinse it. Reduces the light reaching the cells.
Bird droppings. Gulls and other birds near the cliffs. A single dropping shades part of a cell, and because cells are wired in series, a small shaded area can reduce output across a whole string. More: bird droppings on roofs and solar.
Dust and grime settling at the lower edge of the panel, where rain runs off and leaves a band.
Does rain clean them?
Partly. Steeply tilted panels shed some dirt in heavy rain. Shallow-pitched panels and the lower frame edge hold grime. Salt is partly soluble and partly not; rain alone often leaves a film. Dover Heights’ driest months, August to October, are when panels are dirtiest.
How to clean them
Purified water and a soft brush. No detergents unless the manufacturer allows them, no abrasives, no high pressure, which can damage seals and void warranties. Clean early morning or late afternoon, when panels are cool; cold water on hot glass can stress it. More: how to clean solar panels safely and cleaning solar panels on the roof.
Check the panel manufacturer’s cleaning guidance: some specify methods and frequency for coastal sites, and warranties can depend on it.
Safety
Panels are on roofs, roofs are high, and Dover Heights is windy. Do not get on the roof to clean panels yourself. Professional cleaning uses roof access with fall protection or water-fed poles from the ground. Panels are live in daylight; damaged panels or cabling should be checked by an electrician.
Birds under panels
Birds nesting under panels cause mess, noise and damage to cabling. Bird-proofing mesh around the array keeps them out. More: bird-proofing solar panels.
How often
Once or twice a year for most Dover Heights roofs, ideally in spring after the dry months. Monitor your inverter output: a drop on sunny days compared with the same season last year often means dirty panels. More: what solar panel cleaning costs.
Checking whether cleaning is worth it
Most inverters and monitoring apps show daily generation. Compare a clear day now with a clear day at the same time last year, or with a neighbour’s similar system. A noticeable drop on sunny days, with no change in shading, usually means dirty panels. A sharp drop on one string can mean a bird dropping, debris, or a fault.
If cleaning does not restore output, the cause may be electrical: a failed panel, connector or inverter issue. That needs a solar installer or electrician, not a cleaner.
Robots and coatings
Automated cleaning robots and hydrophobic coatings are sold for solar panels. On a residential roof in Dover Heights, a well-timed manual clean once or twice a year is usually simpler and cheaper. Some coatings can affect panel warranties; check with the manufacturer first. More: solar panel cleaning robots.
See the Dover Heights maintenance calendar and our solar panel cleaning service.
