Honest answers
How long do solar panels last?
The first paragraph is the whole answer. Sources, a checklist and nuance follow — no sales stake.
Panels are usually the longest-lived major part of a rooftop system; power electronics and the roof often need attention sooner. Lifetime is a warranty-and-maintenance question, not a guarantee that production stays flat forever.
Separate panel life from system life
Most residential modules carry long workmanship and power-output warranties; many marketing sheets cite roughly 25-year output schedules. That is a contractual degradation path, not a promise of zero issues. Read the output curve, who performs warranty labor, and what voids coverage.
Inverters and optimizers often carry shorter warranties than panels. Budget for at least one power-electronics replacement over a multi-decade roof stay. If the roof needs replacement, removal and reinstallation costs can dominate the economics of panels that still work.
Keep monitoring data. A sudden string or microinverter drop is different from slow soiling. Document serial numbers, permits and interconnection approval so a later owner can service the system.
Before you decide
- Get panel, inverter and workmanship warranties in writing with labor terms.
- Ask the expected inverter replacement window and parts availability.
- Align roof remaining life with the solar plan.
- Save monitoring login, as-built drawings and permission-to-operate records.
Sources
- DOE: Homeowner's Guide to the Federal Tax Credit for Solar Photovoltaics
- DOE: Planning a Home Solar Electric System
Source review: 2026-09-21. Links support the planning points above; they are not a quote, tariff approval or savings guarantee.