Component quality

• Panels

  Tier-1 brands (Longi, Jinko, Trina), 12+ yr product/25+ yr output warranty; mono > poly.

• Inverter

  Hybrid for backup; 5+ yr warranty, service in Ukraine; Deye/SolarEdge/Victron are working brands.

• Battery

  LiFePO4 with BMS, 4000+ cycles, capacity 'with headroom' ×1.3; lead-acid — budget only.

• Install

  Galvanized mounts, PV1-F cable, a measurement protocol; 'cheap install' = a fire in a year.

Skimping on inverter and battery hurts most: a 'second-grade' panel loses 5% yield, but a shady inverter destroys the battery. Warranty and service are part of the price.