Service
Solar panel cleaning in Wellington
Soft-wash cleaning that restores panel output, Wellington dust, bird droppings, salt deposit and pollen lifted without scratching the glass.
What's included
- Pre-clean visual check, James asks about recent output before touching anything
- Soft-wash detergent application (panel-safe, pH-neutral)
- Deionised water rinse via telescopic pole brush, no pressure on the glass
- Frame edge cleaning where most soiling and loss accumulates
- Junction box visual inspection during the clean
- Before-and-after photos for every job
- Written report flagging anything noticed, cracked panels, loose mounts, seal gaps
- Bundle discount when booked alongside a house wash or roof clean
Solar panels represent a real investment, a typical Wellington residential install runs $10,000–18,000, and most homeowners assume the panels more or less look after themselves. The rain will handle it. The technology does its thing. Which is mostly true, except for the part where it isn’t.
James has been cleaning Wellington exteriors since 2001. The soft-wash method used on solar panels, low pressure, panel-safe chemistry, pure-water rinse, is the same approach he’s applied to heritage timber weatherboards, pressed-metal Decramastic roofs and painted surfaces that can’t take any abrasion. The principle is the same: the chemistry does the work, not the water pressure. Solar panels just have a glass surface instead of a painted one, and the cost of getting it wrong (scratched anti-reflective coating, voided warranty) makes the case for doing it carefully even more obvious.
Why Wellington panels need more than rain
The lower edge of a solar panel, where the glass meets the aluminium frame, is where soiling concentrates. Rain runs down the glass surface but slows at the frame junction, deposits its load of dust and organic matter, and evaporates. Repeat that a few hundred times over a summer and autumn and you end up with a compacted strip of debris that no rainfall is going to shift. That strip shadows a section of cells that runs the full width of the panel, and because panels in a string are limited by their weakest link, that shading effect drags output across the whole array.
Wellington adds some specific complications.
Coastal salt deposit is the big one for properties in Lyall Bay, Island Bay, Eastbourne, Petone and along the Kapiti foreshore. Salt crystals from sea spray don’t dissolve in the next rainfall, they accumulate on the glass surface and scatter incoming light. The output reduction is measurable, and it builds gradually enough that most homeowners don’t notice it until James shows them a before-and-after photo with the production figures alongside.
Tree cover is the other major factor. Properties in Karori, Khandallah, Wadestown and Kelburn often sit under mature pines, gums or native trees. That combination of pollen, bird droppings, organic dust and shadow film from leaf residue builds up fast, especially in spring when pollen counts are high and birds are nesting actively.
South-facing roofs in Newlands, Brooklyn and upper Karori have a different problem: algae and moss at the panel edges where shade lingers longest. The panels themselves stay damp for longer than north-facing arrays, and the frame channels become ideal conditions for biological growth that spreads onto the glass margin.
Road dust and diesel film coat panels on properties close to busy roads, Newtown, Aro Valley and the central suburbs see this consistently. It’s a greyish film that reduces light transmission without being visually obvious until you wipe a finger across the surface.
The cleaning method
James cleans solar panels with a telescopic pole brush, panel-safe pH-neutral detergent and a deionised water rinse. That’s the full kit. No pressure washer anywhere near the glass.
The deionised water matters: tap water carries dissolved minerals that deposit as white spots when the water evaporates. Deionised water dries clean, no spots, no residue, no mineral film building up over time.
The detergent is the same class of chemistry used on commercial glazing and heritage glass surfaces. It’s left to dwell briefly on stubborn soiling, particularly bird droppings and compacted frame-edge debris, then rinsed clear. For baked-on deposits from a summer without cleaning, dwell time is what separates a clean result from a frustrating one.
James works from ground level or an extension ladder depending on the roof pitch and the panel position. He doesn’t walk on the panels, doesn’t put ladders against the panel frames, and doesn’t use high pressure at any point.
During every clean, James does a visual check of the junction boxes, visible wiring, mount brackets and panel seals. If something looks worth a sparky’s attention, a seal that’s cracking, a mount that’s working loose, a panel with a visible crack in the glass, it goes in the written report that comes with the after-clean photos.
Pricing
Typical residential system pricing:
- 4kW system (8–12 panels): $180–280
- 6kW system (14–18 panels): $250–380
- Larger arrays, commercial properties and school installations are quoted per site
Book solar panel cleaning alongside a house wash or roof clean and James applies a 10% bundle discount across the combined job. Most customers doing an annual exterior maintenance visit find all three make sense together, the panels are up there, the roof’s up there, and the house is getting washed from top to bottom anyway.
James covers Wellington city, the Hutt Valley, Upper Hutt, Porirua, the Kapiti Coast and the Wairarapa. If you’re not sure whether your property falls in range, the quote form asks for your address and James will confirm when he comes back to you, usually within a few hours.
Recent jobs
Solar Panel Cleaning, before and after.
during 
FAQ
Solar Panel Cleaning, common questions
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Do I really need to clean my solar panels, doesn't rain handle it?
Rain cleans the centre of the panel reasonably well, but it doesn't shift the compacted layer of dust, pollen and bird droppings at the lower frame edge where water pools and dries repeatedly. That lower strip is where the most output loss accumulates. In Wellington, coastal salt deposit and spring pollen add to the problem, neither washes off reliably in normal rainfall.
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How much output am I actually losing?
Light dust and pollen can reduce output by 5–15%. Bird droppings or a salt deposit layer can push that to 20–25%. The numbers vary depending on panel orientation, shading and how long the soiling has been building, but on a 6kW system, even a 10% reduction is a meaningful difference over a year.
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How often should I clean my panels in Wellington?
For most Wellington properties, once a year is enough, ideally in late spring after the pollen season, or in autumn before the shorter days reduce your generation window. Coastal properties in Lyall Bay, Island Bay, Eastbourne and Petone benefit from two cleans a year given the salt deposit rate. Properties under heavy tree cover in Karori, Khandallah or Wadestown may also need the second visit.
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Won't pressure cleaning scratch or crack the glass?
This is exactly why James uses soft wash, not a pressure washer. The cleaning is done with a telescopic pole brush, panel-safe detergent and a deionised water rinse, the water pressure is low enough that it's doing the rinsing, not the scrubbing. High pressure on solar glass risks micro-scratches that scatter light permanently, and can force water into the frame seals. James doesn't use high pressure on panels, full stop.
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What about the inverter and wiring, is it safe to clean while the system is live?
Yes. The panels themselves are cleaned from above with the pole and brush, no electrical components are touched. James does a visual check on the junction box and visible wiring during the clean and notes anything that looks worth a sparky's eye, but the cleaning process itself doesn't require the system to be shut down.
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Do you use chemicals on the panels?
James uses a pH-neutral, panel-safe detergent, the same category of chemistry used on heritage glass and commercial glazing. It's not harsh, it doesn't leave residue, and the deionised rinse water means no mineral spots form as the panel dries. Nothing that touches the glass would void a standard manufacturer warranty.
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Can you clean panels in winter or when it's overcast?
Overcast is fine, James actually prefers it because the panels aren't hot, which means the rinse water doesn't flash-evaporate and leave spots. He avoids cleaning in rain or when conditions are too wet to work safely from a ladder, but a grey Wellington winter's day is perfectly workable.
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What about bird droppings that have baked on over summer?
These are the ones that matter most for output, and they're exactly what the soft-wash method handles well. The detergent is left to dwell on stubborn deposits, it breaks the bond without any abrasive scrubbing on the glass surface. Baked-on droppings that rain has never touched come off cleanly with dwell time.
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Can you do solar panels at the same time as a roof clean or house wash?
Yes, and James offers a 10% bundle discount when solar panel cleaning is booked alongside a house wash or roof clean. Most customers doing an annual maintenance visit find it makes sense to bundle all three.
Ready for a cleaner property?
Most quotes are back within a few hours, sometimes the same afternoon. Fill in the form, James will take a look at your address, and you'll get a straight price with no obligation.