How often should you clean solar panels in Melbourne?

It depends on your roof, but the range is narrow. Most Melbourne homes do fine on an annual clean; commercial sites, and anywhere near trees, traffic or heavy bird activity, are better twice a year. What moves the dial is what's above and around the array.

What actually soils a panel

Panels don't get dirty evenly or predictably. A north-facing array on an open suburban roof sheds a surprising amount with rain. An array under a gum, beside an arterial road, or anywhere birds congregate is a different story — and the loss creeps up slowly enough that you stop noticing it.

• Tree cover and pollen — Melbourne's inner suburbs are leafy, and sap and pollen bond to glass.
• Traffic and construction dust, which settles as a fine film that rain smears rather than removes.
• Bird activity — droppings are acidic, opaque, and tend to land on the same spots.
• Low roof pitch, where water and dirt sit rather than running off.

A sensible schedule

Commercial arrays and anything performance-critical are worth a documented clean and inspection twice a year. A typical residential system in a clean-air pocket can often go to an annual service. Past twice a year you're chasing diminishing returns — two cleans a year is enough; three is a sales pitch. Rather than guess, we look at your output against what the system should produce for its size and orientation, then suggest a schedule that pays for itself.

How you'll know it's time

If your monitoring shows a gradual decline that doesn't track the seasons, soiling is the usual suspect. No monitoring? Visible film, streaking, or bird mess near the array are all reliable cues. A clean typically recovers 5–15% of lost output — the easiest generation you'll ever buy back.