How Long Do Solar Panels Last and What to Expect

Most panels sold today carry a 25-year production warranty, and the panels themselves routinely keep generating well past that. The more useful question is not whether they last, but how much output you lose along the way and which other parts of the system need attention first.

Degradation is slower than most people assume

Modern panels lose roughly 0.3% to 0.5% of output per year. A system producing 100% in year one is typically still around 88-92% in year 25 — a gradual curve, not a cliff.

The inverter is the part that actually wears out

String inverters commonly need replacement around year 10-15; microinverters and battery inverters vary by brand. Budget for this the same way you would a water heater, and check what the manufacturer’s warranty actually covers versus labor.

What shortens the useful life

• Heat: panels run less efficiently and age faster in consistently high roof temperatures.
• Debris and soiling: pollen, dust, and bird activity reduce output until panels are cleaned.
• Poor original installation: loose connections and micro-cracks from mishandling show up as early failures.

A well-installed system on a well-ventilated roof, checked every few years, is the version that reaches 25-30 years of useful production without surprises.