LONGi panels — the safe Mid-tier pick
By Fotovol Team·Updated 26 April 2026
Short answer
Founded in China in 2000, became the world's largest panel manufacturer by volume in 2018. LONGi popularised mono-PERC technology, which drove the price-per-watt collapse of the 2010s. Consistent Bloomberg Tier 1. For a Romanian residential buyer, this is the safe "Mid" pick — competitive pricing, warranties honoured by official distributors, 21–22% efficiency. Watch out for grey-market stock — verify the serial number against LONGi's official database.
When to pick it
LONGi is the "rational default" for 5–15 kWp Romanian residential:
- 5–10 kWp Casa Verde Fotovoltaice system — the Hi-MO 6 or HPBC model at 450–470W offers the best balance of price/quality.
- You want one brand and done — you don't want to read about the subtleties between TOPCon, HJT, IBC. LONGi makes all of them, you can find a good model at any efficiency tier.
- Distributor with track record — Romania has 5–6 official LONGi distributors working directly with the factory. Warranty is honoured through them, not through a small local installer.
Watch-outs
- "Grey" stock through obscure importers — LONGi on AliExpress / OLX at prices 30% below market is either counterfeit or grey-market with no valid EU warranty.
- Hi-MO 5 or older models sold as "new" — that's old PERC, you can find TOPCon at the same price in 2026.
- Suspiciously cheap bundles "LONGi panels + inverter X + battery Y" at a total price 25% below market — someone is cutting hidden costs (mounting, warranty, structure).