Solar Panel Warranties & Maintenance
What warranties to expect in 2026, how they've improved, and how to keep your solar system performing at its best for 25–30+ years.
Typical warranty coverage in 2026
Warranties have improved significantly in recent years, with premium manufacturers now offering 25–40 year product warranties and annual degradation rates as low as 0.25%.
- Panel product warranty: 10–25 years standard (SunPower/Maxeon offer 30–40 years)
- Panel performance warranty: 25–30 years, guaranteeing 80–92% output at year 25
- Annual degradation: typically 0.25–0.5% per year (down from 0.7% a decade ago)
- Inverter warranty: 5–12 years (extended warranties to 20+ years often available)
- Battery warranty: 10–15 years (based on cycles or 70%+ capacity retention)
- Workmanship warranty: 2–10 years (covers installation quality — check with your installer)
What about maintenance?
Solar panels are remarkably low-maintenance. They have no moving parts, and UK rainfall usually keeps them clean enough. However, a few simple steps will ensure your system performs optimally for its full lifespan:
- Annual visual inspection of panels, mounting brackets, and cable connections
- Monitor your system output via the manufacturer's app — any sudden drops may indicate a fault
- Professional cleaning every 2–3 years if panels are heavily soiled, near trees, or bird-affected
- Inverter replacement after 10–15 years is the main ongoing cost (£500–£1,500)
- Battery replacement typically needed after 10–15 years if installed
Protecting your investment
Always ensure your installation is MCS-certified — this is mandatory for SEG payments, most grant schemes, and provides a consumer protection framework. Keep all warranty documents, MCS certificates, and installation records safe. These are needed for any warranty claims, SEG registration, and can add value if you sell your home.
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