By the PPA Funding team Last updated
Commercial solar panels typically last 25 to 30 years or more, with output declining only gradually — usually well under 1% a year. That means a system installed today is still producing the large majority of its original output decades later, long after a PPA term ends.
What degradation means
Panels lose a small fraction of their output each year, a process called degradation. Quality modern panels degrade slowly — often guaranteed to still produce around 85–90% of their original output after 25 years.
Inverters and batteries
Panels outlast most other components. Inverters may be replaced once during the system’s life, and batteries have their own lifespan. Under a PPA the provider handles any replacements as part of maintaining performance.
Value beyond the PPA term
Because a PPA typically runs around 20 years and panels last longer, the system usually transfers to you with years of productive life left — giving you free, self-generated power after the term.
This guide is general information, not financial or tax advice. Your circumstances determine what applies — please confirm with your accountant or advisor. Get a tailored proposal →
Frequently asked questions
Will the panels still work after the PPA ends?
Yes — panels commonly last 25–30 years or more, so a system handed over at the end of a ~20-year PPA still has years of productive life, generating power you then keep for nothing.
Do panels suddenly stop working?
No. They degrade gradually rather than failing outright, so output tapers slowly over decades. Monitoring and maintenance keep them performing throughout.
Related guides
- Do you need planning permission for commercial solar?
- Selling surplus solar: the Smart Export Guarantee for business
- Commercial EV charging and solar: a natural pairing
See our funding options, commercial solar and solar by industry pages.