Updated: June 2026 | ← Back to Blog
How Much Dust Actually Costs You
Studies by MNRE and NISE have measured soiling losses across Indian cities. In Delhi NCR and Kanpur, unclean panels lose 15–25% output per month. In Rajasthan's desert zones, losses hit 20–30%. Even coastal cities like Mumbai and Chennai see 8–12% losses from salt deposits.
The fix costs nothing if you do it yourself — and takes 15 minutes for a typical 10-panel system.
When to Clean
Always clean early morning (before 8 AM) or after sunset. Panels reach 60–75°C on summer afternoons. Cold water on a hot panel causes thermal shock that can micro-crack glass over time. Morning dew also loosens dust, making the job easier.
What You Need
- Soft microfibre mop or squeegee with an extendable handle
- Bucket of plain water (RO or soft water is best — hard water leaves calcium deposits)
- Mild pH-neutral soap (optional — for bird droppings only)
- Garden hose with gentle spray (no pressure washer)
Step-by-Step Cleaning Process
- Gentle rinse first — spray water to loosen surface dust before wiping. Skipping this step drags grit across the glass.
- Wipe with straight strokes — overlap slightly, top to bottom. Do not circular-scrub.
- Spot-treat bird droppings — dab with mild soap on a damp cloth. Do not scrub hard.
- Final rinse — remove all soap residue. Soap residue attracts more dust.
- Air dry — do not wipe dry; cloth-drying can scratch the anti-reflective coating.
What NOT to Do
- ❌ No pressure washer — strips anti-reflective coating, forces water into junction boxes
- ❌ No abrasive pads or steel wool — permanent glass scratches
- ❌ No acid cleaners, bleach, or acetone — damages EVA encapsulant
- ❌ Never clean at noon — thermal shock risk is highest
- ❌ Never walk on panels — cracks cells
Professional Cleaning Services
Professional cleaning services charge ₹20–50 per panel per visit. A 10-panel system costs ₹200–500 per session. Many installers include 4–6 cleanings per year in their Annual Maintenance Contracts (AMC). Professionals use demineralised (DM) water which leaves no mineral residue — better than tap water in hard-water or coastal areas.
Cleaning Frequency by City Type
| Location | Monthly Loss (uncleaned) | Recommended Frequency |
|---|---|---|
| Delhi, Kanpur, Ludhiana | 15–25% | Every 10–14 days |
| Rajasthan (desert zones) | 20–30% | Every 7–10 days |
| Mumbai, Chennai (coastal) | 8–12% | Every 2–3 weeks |
| Bengaluru, Pune | 5–10% | Every 3–4 weeks |
| Kerala, Northeast (high rain) | 2–5% | Every 4–6 weeks |
Does rain clean solar panels sufficiently?
In high-rainfall areas, rain helps significantly. However, light rain at the end of dry season often just makes mud — concentrating soiling. After the first heavy monsoon rain, do a manual clean to remove baked-on deposits.
Will cleaning void my warranty?
Not if done correctly with water and a soft cloth. Using abrasive materials, pressure washers, or harsh chemicals can void the product warranty. Most Tier 1 manufacturers (Waaree, Adani, Vikram) publish cleaning guidelines in their installation manual.