Are used solar panels worth buying?

The used solar market grows every year. Real bargains exist — and so do scams. Here's how to navigate without losing money.

Where used panels come from

• Utility-scale repowering (replace 250 W with 540 W → sell the old)
• Removals during renovations or property sales
• Demo stock or trade-show units
• Cosmetic returns (looks issue, not performance)
• Stolen panels disguised (beware!)

When it's a good buy

5-10 year-old panels (still 85-92% of original capacity), from Tier 1 brands, with clear photos and traceable origin can sell for 30-50% of new price. For a shed, modest expansion or DIY project, it's a steal.

Pre-purchase checks

• Get the serial number and verify with the manufacturer (they confirm year and original owner)
• Look for microcracks with a flashlight behind the panel (no dark lines)
• Multimeter test: Vmp and Imp must be within ±10% of datasheet
• Demand original purchase invoice
• Check for yellowing or delamination

When NOT to buy used

• Polycrystalline panels older than 10 years (obsolete tech)
• No photos of the back (hidden faults possible)
• Untraceable origin (possibly stolen)
• Primary residential install (better to invest in new with warranty)
• If you'll permit interconnection (need a new nominative invoice)

Trusted marketplaces

US: SunHub, eBay with verified pro sellers, Solaris. EU: SecondSol (German, ships across EU). Local: Facebook Marketplace and Craigslist with face-to-face verification.

Before investing compare brands in Tier 1 vs cheap panels and check real lifespan.