How to Clean Your Solar Panels for Maximum Output

Why Panel Cleaning Matters

Soiling — dust, pollen, bird droppings, and pollution — builds up on panel surfaces and blocks sunlight from reaching the cells. Studies show this can reduce output by 15–25% in dry climates like California.

How Often Should You Clean?

• Coastal areas: Every 3–4 months (salt air deposits)
• Inland / desert: Every 2–3 months (heavy dust)
• General rule: After any major dust storm or prolonged dry spell

Step-by-Step Cleaning Guide

1. Time it right — Clean in the early morning or late evening when panels are cool. Cold water on hot glass can cause thermal shock and micro-cracks.
2. Use soft equipment — A soft brush or microfibre cloth with a gentle hose. Never use abrasive scrubbers or high-pressure washers.
3. Skip the detergent — Plain water is almost always sufficient. Soap leaves residue that attracts more dirt.
4. Start from the top — Let dirty water run downward so you're not re-soiling clean areas.
5. Check for damage — While you're up there, look for cracked glass, discolouration, or bird nesting.

When to Call a Professional

If your system shows a significant output drop even after cleaning, there may be an underlying electrical fault. A professional IV curve test can identify underperforming strings that cleaning alone won't fix.