Cleaning is the one maintenance task most owners will actually do themselves, and it is also where most avoidable module damage originates. Both the frequency and the method matter, and the wrong approach can cost more than the soiling it removes.
What maintenance actually involves
Soiling reduces output by scattering light before it reaches the cell. In Karnataka conditions this typically costs a few percent, rising substantially near construction, unpaved roads, or heavy tree cover with bird activity. The monsoon largely cleans panels for free, so the meaningful cleaning window is the long dry stretch from roughly November through May.
| Site condition | Suggested interval | Notes |
|---|---|---|
| Typical urban rooftop | Every 2-3 months | Less often during monsoon |
| Near construction activity | Monthly | Cement dust bonds and is harder to remove |
| Heavy tree cover or bird activity | Monthly | Droppings cause concentrated hot spots |
| Dusty or unpaved surroundings | Monthly to 6 weeks | Dry districts accumulate faster |
| During monsoon | Rarely needed | Rain does most of the work |
A practical starting point rather than a fixed rule. Monitoring output before and after a clean is the most reliable way to find the right interval for your specific roof.
The engineering view
Clean early morning or late evening, never on a hot module. Cold water on hot glass causes thermal shock and can crack cells. Use plain water with a soft brush or microfibre on a pole; avoid detergents, which leave residue that attracts more dust. Never use a pressure washer, since forcing water past the frame seal is a route to moisture ingress and delamination. And never walk on modules — the glass may not break visibly but the cells beneath crack, creating permanent dead spots.
Local operating conditions
Bengaluru's construction activity is the single biggest soiling factor for many rooftops, and cement dust is considerably more stubborn than ordinary dust. Water quality matters too: hard borewell water leaves mineral deposits that scatter light almost as effectively as the dirt you removed. Where the supply is hard, a final rinse with softer water is worth the trouble.
Common mistakes to avoid
Cleaning causes more module damage than any other owner activity:
- Spraying cold water onto panels that have been in full sun
- Using a pressure washer, which drives water past the frame seal
- Walking on modules to reach the far rows
- Cleaning with detergent, leaving residue that attracts dust faster
- Using hard borewell water and leaving mineral deposits behind
What we recommend
Clean early in the morning with plain soft water and a soft brush on a pole, at an interval you set by watching your own output rather than by rule of thumb. If reaching the array safely requires standing on modules or leaning from an edge, that is the point to hand the job to someone with proper access equipment.
Common questions
- How often should I clean my panels?
- Every two to three months suits most urban rooftops, monthly near construction or heavy tree cover. Watching output before and after tells you what your roof actually needs.
- Can I use soap or detergent?
- Better not to. Residue attracts dust and can streak. Plain water with a soft brush is what the glass needs.
- Is rain enough during monsoon?
- Largely yes. The monsoon does most of the cleaning, which is why the dry months are when attention is needed.
- Can I use a pressure washer?
- No. The pressure can force water past the frame seal and cause moisture ingress, which is not recoverable.
- Does bird droppings matter more than dust?
- Yes. Droppings block light completely over a small area, which can create a hot spot rather than just a general output loss, so they are worth removing promptly.
Talk to our engineering team for a solar assessment.
We will review your consumption, roof, and site constraints before recommending any capacity.