Solar Panel Cleaning and Maintenance

How Soiling Affects Solar Panel Performance

Photovoltaic modules convert sunlight into electricity through a chemical reaction in silicon cells. Any obstruction between the sun and the panel surface, dust, salt, bird droppings, pollen, or industrial pollution, reduces the photons reaching the cells, directly lowering power output. Unlike a dirty window, soiling on solar panels has an immediate and measurable financial impact.

Studies across Southeast Asia consistently show soiling losses of 15% to 25% after 3 to 6 months without cleaning. In extreme cases, such as coastal Thailand during dry season when salt spray accumulates, or inland areas near construction sites where red dust coats panels, losses can reach 30% to 40%. A 5 kilowatt-peak system producing 25 kWh daily when clean may drop to 17 kWh with heavily soiled panels, costing you 8 kWh of free electricity every single day.

Soiling also creates localised heating. When part of a panel is shaded by debris, that section stops generating power and becomes a resistive load, heating up the surrounding cells. This thermal imbalance can trigger bypass diodes and reduce string output. Over time, persistent hot spots accelerate Potential Induced Degradation (PID), a slow but permanent loss in panel performance caused by voltage stress and moisture ingress.

Thailand-Specific Soiling Challenges

Our Cleaning Process and What You Get

We use deionised water and soft-bristle brushes designed specifically for photovoltaic glass. Deionised water leaves no mineral residue, unlike tap water which contains calcium and magnesium that form spots when it evaporates. Our technicians work from secure ladders or scaffolding, never walking directly on panels, which can crack cells and void warranties.

• ✓ Visual inspection: Before cleaning, we photograph each panel and check for cracks, delamination, discolouration, or hot spots using a thermal camera.
• ✓ Deionised water rinse: Low-pressure spray removes loose debris without forcing water into junction boxes or under frame seals.
• ✓ Soft-brush agitation: Biodegradable cleaning solution breaks down stubborn deposits. Brushes have flagged tips that cannot scratch tempered glass.
• ✓ Final rinse and dry: Squeegee removal of excess water prevents streaking. We clean in early morning or late afternoon to avoid thermal shock on hot panels.
• ✓ Performance verification: We measure power output before and after cleaning, providing a report showing energy recovery in watts and percentage.
• ✓ Maintenance recommendations: We advise on optimal cleaning frequency for your location, typically every 3 months for coastal properties, every 6 months for inland areas.

Recommended Cleaning Schedule by Location