A common question among Victorian solar panel owners is whether rainfall is sufficient to keep panels clean, or whether regular manual washing is necessary to maintain maximum output.
When Rain is Enough
For panels installed at a tilt angle of 10 degrees or greater, typical Victorian rainfall does an admirable job of washing away light surface dust and pollen. The anti-reflective hydrophobic coating on Tier-1 monocrystalline panels causes water droplets to bead up and carry loose dirt down toward roof gutters.
When Manual Cleaning is Needed
Rain alone will not remove baked-on bird droppings, sticky tree sap, heavy lichen, or greasy industrial grime near busy highways or industrial zones. If stubborn debris blocks solar cells, it can create localized "hot spots" that reduce system generation by 5% to 15%.
We recommend a quick visual inspection every 6 to 12 months. If required, gently spray down the panels in the early morning with cold mains water and a soft microfibre telescopic brush. Never use harsh detergents or abrasive high-pressure washers.
Billabong Solar Admin
NETCC Approved SpecialistSenior Solar Energy Engineer • Billabong Solar Victoria
The Billabong Solar engineering and technical team brings over a decade of hands-on experience designing and commissioning NETCC approved residential and commercial solar arrays and battery storage solutions across Melbourne and regional Victoria.
