In much of Cremorne, solar panels live where you cannot see them. North Sydney Council's solar guidance for heritage conservation areas says panels are not to be attached to a wall or roof facing a primary road, so home arrays can end up on rear roofs, and a flat-roofed block may have its panels behind a parapet. A dirty array gives no visual warning from the street. Solar panel cleaning uses purified water with no detergent to remove what has built up, and it dries spot-free on the glass.

Roof shape decides how well rain can help. Council's conservation area statement records corrugated metal and skillion roofs on the rear of many Cremorne houses, and a low skillion gives water far less fall than a 45-degree main roof. Panels on a flat-roofed inter-war block may sit at a shallow frame angle inside a parapet, a position where dust can stay for longer.
What settles on them depends on your distance from the ridge. Military Road runs along the top of it as a major regional thoroughfare with high frequency buses, and arrays on nearby roofs are exposed to exhaust soot and fine road grime. Down on Cremorne Point, between Shell Cove and Mosman Bay, council's Street Tree Strategy points to salt-laden winds along the water frontages, which leave a thin film.
Birds are the third factor, and council is deliberately encouraging local wildlife. It describes the Angophora planting on Murdoch Street as part of a wildlife corridor linking Willoughby Bay bushland to Cremorne Point, and Primrose Park adds a significant area of urban bushland to the north. Droppings on glass block the light completely in that spot, unlike a film of dust.
Cleaning removes dust, salt film, pollen, soot and bird droppings without leaving any residue behind.
Most owners judge their panels by the app, and a slow decline is hard to read there. Soot and salt spread evenly, so output drifts down without any single moment that looks like a fault. A clean removes that question, and comparing generation figures before and after shows what the dirt was costing.
Seeing the array matters almost as much. Council's controls push panels away from prominent roof planes and front elevations, which leaves many owners with no line of sight to their own system. Before-and-after photos with every job show the condition of the glass and frames from a position you cannot easily reach yourself.
Purified water suits the glass for two reasons. It dries without mineral spots, and without detergent there is nothing left on the coating to catch the next layer of dust. It also means only what came off the panels runs towards the gutters and, eventually, the harbour.
For a shared system on a strata building, the record is useful for reporting to owners and for showing that the asset is being kept up. Our team members are certified to work safely at heights and the business is fully insured, which a strata manager may want confirmed before anyone goes up on common property.
Watch your inverter or app for generation that seems low for the weather, compared with the same period last year if you have it. The before-and-after photos taken with a clean then give you a clear view of the array itself, which is otherwise hard to get.
Exhaust soot and fine road grime can settle on nearby roofs, and rain does not always clear a greasy film from glass. Military Road carries a lot of bus and regional traffic along the ridge. Purified water lifts that film without detergent and dries spot-free, leaving nothing behind on the coating.
Usually, though how the roof is reached is assessed when quoting, including access hatches and where equipment can go. Strata and commercial buildings are covered, team members are certified to work safely at heights and the work is fully insured. The committee or managing agent is normally the right contact.
Cleaning leaves the panels exactly where they are and adds nothing to the roof, so it is ordinary maintenance rather than a change to the building. Questions about moving or adding panels in a conservation area belong with North Sydney Council, whose planning staff can explain what applies to your property.
How we clean arrays with purified water and no detergent, and why output recovers once the glass is clear.