Solar panels are typically warranted for 25 years, and field data shows they lose only around half a percent of their output each year. A 50 kWp array Spirit Energy installed near Winchester in December 2011 had its best year ever in 2022, when it generated 54,600 kWh at 11 years old. On most systems the inverter, not the panels, is the first part to need replacing, usually somewhere between years 10 and 15.
