If you live in Port Harcourt, you know the black soot. It is on cars, floors and clothes. It also lands on solar panels.
How soot hurts output
Panels need light to reach the cells. Soot blocks it. The film is oily, so it sticks.
| Panel condition | Output loss (rough) |
|---|---|
| Clean | 0% |
| Light dust | 2–5% |
| Visible soot film | 5–15% |
| Thick dirt and droppings | More |
How often to clean
- Dry season / harmattan: every 4 to 6 weeks
- Rainy season: after long dry spells
- Any time you see a dark film
Safe cleaning steps
- Clean early morning or late afternoon, when panels are cool.
- Use clean water and a soft brush on a long pole.
- A little mild soap if needed. Rinse well.
- No abrasive powders. No pressure washers.
- Do not stand on the panels.
On an upstairs building, leave roof work to people with proper access gear. Read how to clean solar panels safely.
Check your gain
Look at your inverter's daily solar output before and after cleaning. You will see the difference.
