Dirty panels can lose 5–25% of their output. A proper clean is one of the cheapest ways to get that production back.
Hunter Valley solar panels see a lot — bird droppings, pollen from the surrounding vineyards and bushland, dust from harvests, summer storms that leave grit behind. Rain helps, but it doesn't clear baked-on bird waste or the lichen that creeps in under panel edges. After a year or two, you can be losing real money without realising it.
What's actually happening to dirty panels
Independent studies put typical soiling losses at around 5%, rising to as much as 25% in agricultural or coastal areas with heavy bird activity. On a 10 kW system, that can be hundreds of dollars a year in lost generation.
Bird droppings and lichen create shaded patches that force individual cells to dissipate the current the rest of the panel is producing — as heat. Long-term, that causes permanent cell damage and warranty disputes.
Many panel manufacturers expect panels to be kept reasonably clean and maintained — and a regular cleaning record helps if you ever need to make a warranty claim.
This is not a job for a homeowner with a garden hose and a ladder. Wet panels are slippery, and a fall from a roof is serious — it's worth leaving to someone who does it for a living.
A sensible cycle for Hunter Valley conditions
For most Hunter Valley homes, every 12–24 months keeps panels close to factory-clean. Properties near vineyards, bushland, or with heavy bird traffic should aim for annual cleans. Coastal homes (salt deposit) and farm properties (dust + droppings) benefit from twice-yearly cleans.
If you're due for an annual service, it's typically cheaper to do the clean at the same time — we're already on the roof. See system servicing →
