Rooftop arrays on warehouses and factories, solar carports over staff parking, and ground-mount systems on industrial land — cleaned with deionised water and soft brushes, no chemicals and no high pressure, by crews certified to work at height.
Commercial solar arrays are cleaned with deionised water and soft brushes at low pressure, never with detergents, abrasive pads or high-pressure lances, which manufacturers prohibit. Most Sydney commercial rooftops suit a twice-yearly clean, adjusted by what the inverter data shows. All elevated work runs under a site-specific Safe Work Method Statement, and every clean is documented with before and after imagery for the facilities file.
A residential system on a pitched tiled roof sheds a lot of its own dirt. A commercial array on a Sydney warehouse does not, and the reasons are structural rather than cosmetic. Commercial roofs are near-flat, so modules sit at a low tilt where water pools and evaporates in place instead of running off. The array is large, so the bottom edge of every panel becomes a collection line for everything the rain washes down. And the roof is usually in an industrial setting where the air carries something: brake and tyre particulate near an arterial road, fines from an unsealed yard, exhaust film from the plant next door, salt from the coast.
The mechanism that costs you the most is not general dulling of the glass, it is localised shading. Cells inside a module string operate in series, so the weakest cell sets the ceiling for the string. A hard band of dried grime along the bottom cell row, a single set of bird droppings, or a lichen patch growing off the frame edge does disproportionate damage compared with the same amount of dirt spread evenly. This is also why a soiled array does not always look soiled from the ground.
Sydney adds a specific seasonal pattern. Spring pollen binds to the film already on the glass, summer storms deposit and then bake, and the long dry stretches between rain events let everything cure hard. Arrays near the port, near Sydney Airport or on the coastal fringe carry a salt component that is hygroscopic — it re-wets in humidity and pulls fresh dust into the layer.
Warehouse and factory rooftops. The largest arrays we clean and the ones with the hardest access questions. Metal deck roofs with fragile skylights, limited or no anchor points, and a long carry for hoses and equipment. We resolve access before we resolve cleaning: anchor point certification, a compliant edge, or an EWP working from outside the building line. Skylight and roof sheet condition is noted, because a solar clean is often the first time anyone has walked that roof in years.
Solar carports. Increasingly common over staff and customer parking at business parks and retail centres. The soiling is organic rather than mineral — leaf litter, sap, bird droppings from surrounding trees — and organic soiling needs dwell time and gentle agitation rather than force. Carports also need vehicle management: bays cleared or coned, and drips controlled so we are not rinsing a customer's car with roof runoff.
Ground-mount arrays. Found on industrial land in the west and on large-site campuses. The bottom row takes soil splash after every rain event, and grass or weed growth between rows both shades the panels and holds moisture against the frames. Vegetation management belongs in the maintenance plan alongside the clean, otherwise the array is soiled again within weeks.
Solar glass is cleaned with deionised water for a reason that has nothing to do with marketing. Ordinary mains water in Sydney carries dissolved minerals; when it dries on glass it leaves those minerals behind as spotting, and spotting on a panel is exactly the localised shading you were trying to remove. Deionised water has had those minerals stripped out, so the surface dries clear with no residue and no need for a detergent to carry the dirt away.
The method is soft-bristle brushing on a water-fed pole with a low-pressure flow. No detergents, because surfactant residue attracts dust faster than clean glass and can attack frame seals over time. No abrasive pads or scourers, because module glass carries an anti-reflective coating that scratches and, once scratched, permanently scatters light. No high-pressure lance, because pressure directed at a frame edge or a junction box drives water past seals and creates a fault that is far more expensive than the soiling was.
Timing matters too. We clean early, while the modules are cool. Putting cool water onto glass that has been sitting in full Sydney summer sun is a thermal shock risk, and it also flash-dries before it can be worked. Sites where the same principles apply to the rest of the building envelope are usually done in one visit with our building facade cleaning crew.
A commercial array clean is a height-safety job that happens to involve water. All staff working on elevated sites hold Working at Heights certification, and every job runs under a Safe Work Method Statement written for that specific roof: the access route, the anchor or edge protection arrangement, the fragile-surface controls for skylights, the exclusion zone below, and the emergency retrieval plan. A generic SWMS pulled from a folder is not a plan, and most Sydney facilities managers will not accept one.
Where a roof has no compliant fall protection, the honest answer is not to improvise. We either work from an elevated work platform outside the roof line, restrict the clean to the rows reachable from a compliant position, or tell you the array needs anchor points installed before it can be serviced safely. Facilities managers get that recommendation in writing so it can go into the capital plan.
Site inductions, certificates of currency and permit-to-work paperwork are lodged before attendance rather than negotiated at the gate. On operating industrial sites we work to your contractor management system the same way our industrial cleaning crews do.
Twice a year is the sensible starting point for a Sydney commercial rooftop, and then the site tells you what it actually needs. Distribution warehouses with sealed yards and no nearby industry often sit comfortably at that interval. Sites beside unsealed hardstand, quarries, concrete batching, timber processing or a busy freight route usually move to quarterly because the deposition rate is simply higher.
Food manufacturing and commercial kitchens with roof-mounted exhaust are their own category: the film is greasy, it bonds, and it traps dust rather than shedding it. Those arrays need a shorter interval and a longer dwell on each clean. Coastal and near-port sites deal with salt, which is less about opacity and more about corrosion at the frame and clamp, so the inspection component matters as much as the wash. Anywhere with a bird pressure problem — roosting on the array edge or on nearby structures — needs deterrent work in parallel or the clean will not hold.
If the same roof also has box gutters and downpipes feeding into the array's runoff path, it is worth bundling the visit with commercial gutter cleaning so the roof access, SWMS and traffic management are paid for once rather than twice.
Solar cleaning is one of the few cleaning services where the client can verify the result independently, and we think that is a good thing. Every clean is documented with dated before and after photography of representative rows, notes on anything found on the roof — cracked modules, lifted clamps, corroded frames, damaged cabling, blocked drainage, bird nesting under the array — and a record of the access method used. That pack goes into your maintenance file and gives you something to hand to your solar service contractor if a fault is found.
We do not publish a promised percentage recovery, and we would be sceptical of anyone who does: the gain from a clean depends entirely on how soiled the array was, how the soiling was distributed across strings, and the weather in the comparison window. The honest measure sits in your own monitoring platform. Note your generation over the fortnight before the clean and the fortnight after, on comparable weather, and let the inverter data set your cleaning interval from there.
For a quote we need the roof type, the approximate number of modules, the tilt, the access arrangement and whether the array has been cleaned before. Call 1300 494 983 or send through the site details. Warehouse operators usually scope this alongside their warehouse cleaning schedule.
No detergents, no abrasives, no high-pressure lance near frames.
Site-specific SWMS, EWP where the roof has no compliant edge.
Dated before and after imagery plus a defect note for your file.
For most Sydney commercial rooftops we recommend twice a year as a baseline, timed for late autumn and late spring so the array is clean going into the two periods where output matters most. Sites with a specific soiling source clean more often: warehouses near quarries, unsealed yards or major arterial roads, food manufacturing with exhaust discharge nearby, coastal sites carrying salt film, and any roof under a flight path or beside a bird roost. Rather than guessing, we suggest starting at twice a year and letting the inverter data set the real interval.
Cleaning does not void a warranty when it is done the way the manufacturer specifies, but the wrong method absolutely can. Every major module warranty prohibits abrasive pads, high-pressure water directed at frames or junction boxes, and harsh chemicals, and several specify a maximum water temperature and pressure. We work to deionised water and soft brushing at low pressure, which is the method most manufacturers name in their operations and maintenance documentation. Send us your module and mounting O&M manuals before the first clean and we will work to those documents specifically.
Yes. All staff working on elevated sites hold Working at Heights certification, and every rooftop or elevated array is cleaned under a Safe Work Method Statement prepared for that specific site rather than a generic document. Where the roof has no compliant anchor points or edge protection we use an elevated work platform and clean from outside the roof line, or we tell you the array cannot be safely accessed until fall protection is installed. We will not send a crew onto a roof that does not have a workable access plan.
Rain rinses loose dust but it does not remove the bonded layer, and on a low-tilt commercial array it can make things worse. Water sheeting down a shallow-pitch panel carries dissolved grime to the bottom edge where it collects against the frame and dries into a hard band. That band sits over the lowest cell row, and because cells within a string behave in series, shading a single row can drag down the whole string rather than just its own area. The frame edge is exactly the part rain will never clear.
In most cases yes. Cleaning is done on the glass surface with the system live, early in the morning while the modules are cool and output is low, which is also when thermal shock risk is lowest. Where a site requires isolation for access reasons, we coordinate the shutdown window with your facilities manager or solar maintenance contractor so it lands outside your peak tariff period. We do not open, disconnect or work inside electrical enclosures — that is licensed electrical work and it stays with your solar service provider.
Yes. Ground-mount arrays on industrial land and solar carport structures over staff parking are both common in Western Sydney and both have their own issues. Ground-mounts pick up soil splash from the lowest row up and often sit in grass that needs to be managed before cleaning is worth doing. Carports collect leaf litter, sap and bird droppings that bond harder than dust and need dwell time rather than force. Both are quoted per array after we look at the tilt, row spacing and the access route for water and equipment.
Tell us the roof type, module count and access arrangement. We come back with a method, a SWMS approach and a fixed price.
