Solar Panel Warranties

Solar panels come with some of the longest warranties in consumer goods — but the details matter.

Two Types of Warranty

Product Warranty (10–25 years)

Covers manufacturing defects, material failures, and premature degradation. If a panel stops working due to a defect, the manufacturer replaces it.

• Budget panels: 10–12 years
• Mid-range panels: 15–20 years
• Premium panels (REC, SunPower, LG): 25 years

Performance Warranty (25–30 years)

Guarantees the panel will still produce a minimum percentage of its rated output after a specified period.

The industry standard:

• Year 1: minimum 97–98% of rated output
• Year 25: minimum 80–85% of rated output
• Degradation rate: 0.4–0.7% per year

Premium panels may guarantee 92% at year 25 with only 0.25% annual degradation.

Inverter Warranty

Inverters have shorter warranties because they have electronic components that wear out:

• String inverters: 5–10 years standard, extendable to 15–20 years for €200–€500
• Microinverters: 20–25 years (Enphase standard)
• Optimizers: 20–25 years (SolarEdge standard)

Always extend your string inverter warranty. The inverter will likely need replacement during the panels' lifetime, and an extended warranty costs far less than a replacement.

Workmanship Warranty (2–10 years)

This covers the installation itself — roof penetrations, wiring, mounting. Provided by your installer, not the manufacturer.

• Minimum acceptable: 5 years
• Good: 10 years
• Red flag: Less than 2 years, or no written workmanship warranty at all

What Voids a Warranty

• Unauthorized modifications or repairs
• Installation by uncertified installers (for product warranty)
• Physical damage from impacts, improper cleaning, or walking on panels
• Not following manufacturer's maintenance guidelines

Tips

1. Read the fine print — some warranties require you to register the product within 30 days
2. Keep all documentation — invoices, serial numbers, registration confirmations
3. Check warranty transferability — important if you sell your home
4. Verify the manufacturer's financial stability — a 25-year warranty from a company that goes bankrupt in 5 years is worthless
5. Extend the inverter warranty at purchase — it's always cheaper than buying separately later

Compare warranty terms when evaluating quotes from installers in our directory.