In a new report released by SolarCity, we are seeing that solar power systems have a usable lifetime of at least 35 years – 40% longer than the market expects. The key finding of the report is that power degradation (annual efficiency loss) of solar panels supplied to SolarCity is as much as 35% lower than for a comparable industry-wide selection of non-SolarCity panels, which are typically expected to last for 25 years. SolarCity feels it is the implementation of a stringent and industry-leading “Total Quality Program” that has driven this. expand full story