Picking a solar-panel installer — 7 checks against scammers
PV market has both excellent and scammy players. 7 checks (RnQ-cert, warranties, inverter brand, insurance) reveal the difference.
7 checks: (1) RnQ or Zon-Keur installer certification; (2) panels on BloombergNEF Tier-1 list (quality, financially solvent); (3) inverter — established brands (SolarEdge, Enphase, GoodWe, Huawei, SMA); (4) warranties — 12-25 yr product, 90% performance after 25 yr, 10-12 yr inverter; understand brand vs installer warranty difference; (5) installer insurance > €1M, KvK > 3 years; (6) references + photos + Trustpilot rating; (7) price — €1.20-€1.80/Wp (incl. VAT 2026 + install) is realistic; much lower = likely poor-quality panels or hidden installer margin. Red flags: "deliver tomorrow" pressure, no paper quote, 100% upfront, no certification mark. For SMEs: combine with EIA/MIA deduction.