Solar panel cleaning is one of the easier maintenance jobs to overpay for and one of the easier ones to skip for too long. Here is what it costs in Sydney, what changes the price, and how to work out whether it is worth it on your system.
Typical Sydney pricing
Most residential work is quoted per panel, with a minimum call-out.
Single storey, easy access: commonly $8 to $15 per panel, with a minimum around $150 to $200.
Two storey: commonly $12 to $25 per panel, minimum around $250 to $350.
So a typical 20-panel system on a single-storey house generally lands somewhere between $180 and $300, and the same system on a two-storey house between $300 and $500.
Larger systems get a better per-panel rate. Very small systems are usually just the minimum.
What moves the number
Height and access. The biggest single factor. Two storeys means harness work, anchor points and a slower, more careful job. A steep block or a property where a truck cannot get close moves it again.
Roof pitch. Anything over about 25 degrees requires fall protection and slows everything down.
Roof type. Tile is more fragile than metal and takes longer to move across safely. Broken tiles found afterwards are an argument nobody enjoys.
How dirty they are. Normal dust and pollen is a straightforward wash. Bird droppings baked on through a summer, lichen at the panel edges, or sap from an overhanging tree all take considerably longer.
Bird mess underneath. If pigeons have been nesting under the array, that is a different job with its own scope — clearing, decontamination and usually gutter work. See bird proofing solar panels.
Water quality. Proper jobs use deionised or demineralised water for the final rinse so the panels dry without mineral spotting. Tap water dries with a film that reduces the benefit of having cleaned them.
Is it worth it
The honest arithmetic, because this is the question that actually matters.
Soiling losses on a Sydney residential system are typically in the range of 5 to 15 percent, rising for systems under trees, near construction, on main roads, or with heavy bird traffic. Rain removes some of it, but not the greasy, bonded layer, and not anything in the bottom edge of the frame where water sits.
A 6.6 kW system in Sydney produces roughly 9,000 kWh a year. At a blended value of around 15 cents per kWh — somewhere between what you save on consumption and what you earn on export — that is about $1,350 a year of generation.
Recovering 8 percent of that is roughly $108 a year. On a $250 clean, that is a payback over a bit more than two years, which is why annual cleaning is often oversold.
Where the numbers change sharply: a heavily soiled system recovering 15 percent or more, a larger system, a system under trees or with bird fouling, or one on a higher feed-in or consumption profile. In those cases the clean pays for itself inside a year.
Our piece on what actually costs you output goes into which types of soiling matter most.
How often
For most Sydney homes, every 18 months to two years is a reasonable interval.
More often if you are under trees, near the beach where salt film accumulates, near heavy construction, on an unsealed road, or if birds are using the array.
Less often on a steep roof with no overhanging vegetation in a clean suburb, where rain does most of the work.
The practical check is your own generation data. Most inverters have an app. Compare this spring to last spring in similar weather. A persistent gap that is not explained by cloud is soiling.
What a proper job includes
- A visual inspection of the array, frames, fixings and visible cabling, with anything noted reported to you
- Soft brushing with a non-abrasive head and a pH-neutral cleaner where needed
- Deionised water final rinse so panels dry spot-free
- Clearing of debris from under and around the array
- Gutter check, because that is where the debris has been going
- Before and after photos
- Height safety and public liability cover
What should not be in it: high pressure, abrasive pads, detergents that leave a residue, or anyone touching the DC isolator or cabling, which is licensed electrical work.
Doing it yourself
Possible, and we have written how in how to clean solar panels: the safe way.
The honest version: on a single-storey roof with a shallow pitch and a long extension pole from a stable position, it is reasonable. On a two-storey roof it is not a sensible saving. Falls from height are the main way people are seriously hurt doing their own home maintenance, and the amount being saved is a few hundred dollars.
Never clean panels with cold water in the middle of a hot day — thermal shock on hot glass is a real risk of cracking. Early morning is the right time.
Getting a quote
Ask for the per-panel rate and the minimum, whether deionised water is used, whether the gutter check is included, and whether you get photos.
And ask whether they will tell you if the panels do not need doing. See solar panel cleaning for how we scope it — including the cases where we look at a system and say come back next year.
