4 hours ago
- Cleaning a small solar farm with visibly dusty panels resulted in a 2%-5% increase in power output, translating to an estimated £60-£150/year benefit that decays over several years.
- The experiment involved comparing power ratios between two banks of 16 panels, washing one bank while using the other as a control to account for varying sunlight conditions.
- An unexpected drop in power ratio occurred after washing one panel, and a subsequent decline after all panels were washed suggested possible water evaporation causing an opaque effect.
- The author experienced a mild electric tingle during cleaning, attributed to capacitive leakage from a transformerless inverter, and advises cleaning at night to avoid such discomfort.
- Upgrading the 15-year-old 3.7 kW system with modern panels could boost output by 60% for £5000, paying off in ~3 years, but the existing high-value feed-in tariff makes additional capacity ineligible for the same rate, creating a disincentive to upgrade.