Should you wash your solar panels?

	Should you wash your solar panels?(incoherency.co.uk)
	236 points by surprisetalk 22 hours ago \| 234 comments
	tl;dr: Cleaning visibly dusty solar panels yielded a 2-5% power output increase (worth ~£60-150/year) by comparing power ratios between two banks before and after washing one. Upgrading the 15-year-old 3.7kW system to modern panels would boost output ~60% and pay back in 3 years, but doing so would forfeit a lucrative legacy feed-in tariff, making the upgrade economically unattractive.
	HN Discussion: ↓Cleaning yields much larger gains (10-40%) than the article's modest 2-5% figure ~Long-term owners report minimal degradation and rely on rain, questioning need for washing •Technical explanations for the measurement curve shape (panel matching, cooling effects) ↑Economics of cleaning are oversold; article correctly highlights modest real returns ~Creative workarounds like separate new systems to preserve feed-in tariff