Do solar panels wear out?

Over a long period of time, solar panels do wear out in the sense that they become less efficient at converting solar energy into usable electricity. The panel structure itself (frame, glazing, etc.) should not wear out, barring manufacturer defects. The problem lies in degradation of the solar cells within.

That breaking down is a very slow process over many years. Most panels in use today will last 25-40 years, while still maintaining as much as 80 percent of their original output. A 20-year and 80-percent output warranty is an industry standard. Many have 25-year warranties and most people agree that panels will produce power almost indefinitely. It is far more likely that wiring or an inverter will wear out before the solar panels do.

Why Do Solar Cells Degrade Over Time?

Over time, the chemicals and elements that make up the chemistry of a solar cell degrade, for they age like every other substance on earth. Silicon is the most durable and most efficient solar cell material we know (and can market) today, which is why it functions in about 90 percent of all solar panels in use. The sunlight striking a solar cell, most of which is reflected back or lost as heat, gradually begins to have a negative effect on that cell. It begins to break down.