Yes, you can clean your own solar panels — and on a safe single-storey roof, you probably should. A cleaning company will charge from IDR 500,000 per visit; a bucket and the right brush cost less than that once and last for years. As the people who sell the professional version of this service, here is the honest guide: what to buy, how to do it without damaging anything, and the genuinely short list of situations where you should call us instead.
Why Bother at All
Bali's dry season is the dirty season. From May to October there is no rain to rinse the array, so road dust, ash from burning season and salt film near the coast accumulate into a stubborn haze, glued on by morning dew. Add a few bird droppings — each one shading a cell and dragging down its whole string — and a typical neglected villa array loses 10–25% of its output. On a 5 kWp system that is up to IDR 165,000 of electricity every month, silently.
What You Need (with Real Prices)
- Soft-bristle brush on a telescopic pole — IDR 250,000–450,000 at any larger hardware store. Soft means soft: car-washing or window-cleaning grade, never a scrubbing broom.
- Garden hose with a gentle spray nozzle — IDR 100,000–150,000 if you do not own one. Never a pressure washer.
- Water squeegee on the same pole — IDR 80,000–120,000, optional but nice for a spot-free finish.
- Demineralised (deionised) water — IDR 15,000–25,000 per 5-litre jug at automotive shops (sold for car batteries and radiators), for the final rinse if your tap water is hard. Collected rainwater works too.
- Mild dish soap — a few drops in the bucket, only for greasy films and droppings. No detergents, no glass cleaner, no abrasives.
Total kit: under IDR 700,000, reusable for years.
The Method, Step by Step
Pick the right hour
Early morning (before 9) or late afternoon (after 4). The panels must be cool — this is a safety-of-the-glass rule, not a comfort tip, as you will see below.
Check your monitoring app first
Note yesterday's production. It is your before/after proof, and the habit that catches real faults early.
Rinse before you brush
Hose the whole array top to bottom to float off loose grit. Brushing dry dust grinds it into the glass like sandpaper.
Brush gently, top to bottom
Light pressure, straight runs, letting water do the work. Soak stubborn bird droppings with a wet sponge for a minute instead of scraping them.
Final rinse and squeegee
Rinse with demineralised water or rainwater if your tap water is hard, then squeegee. Check the app over the next sunny days and enjoy the bump.
The Mistakes That Actually Cause Damage
Washing hot panels at midday
The number one glass-killer. A panel in full Bali sun runs at 60–70°C; hit it with cool hose water and thermal shock can crack the glass or, more insidiously, micro-crack cells invisibly. Damage from improper cleaning is also a classic warranty-claim rejection. Morning or late afternoon, always.
Hard well water
Much of Bali sits on mineral-heavy groundwater. Let it dry on hot glass and it bakes on as white mineral spotting — a permanent haze you cannot brush off, doing exactly what the dirt was doing. If your kettle furs up, your panels will too: final-rinse with demineralised water or rainwater.
Walking on the panels
Never. Glass rated for hail is not rated for a concentrated heel strike — cells micro-crack under loads that leave no visible mark, and output decays for years afterwards. If you cannot reach every panel from a ladder, a walkway or a safe standing position, that array is not a DIY job.
Pressure washers and stiff brushes
High-pressure jets force water past the frame seals and junction-box gaskets; stiff bristles and abrasive pads put permanent micro-scratches in the anti-reflective coating. Hose pressure and soft bristles, nothing more.
When to Call a Professional Instead
The honest list is short. Height: two-storey roofs, steep clay tile or anything requiring harness work — no electricity saving is worth a fall, and wet tile roofs are treacherous. Persistently low output: if production stays down after a good clean, the problem is electrical — a failing connector, string fault or inverter issue that needs proper diagnostics, not more soap. Coastal salt crust within a few hundred metres of the surf, which bonds harder than dust and benefits from professional water and inspection of connector corrosion at the same visit. Our cleaning and maintenance service covers all three cases, with output measured before and after.
Not sure whether your situation is DIY-safe? Send a photo of your roof on WhatsApp and we will tell you honestly — including "that is an easy one-storey roof, do it yourself" when it is true. The consultation costs nothing.