... Certification 3 High efficency 17% 4 Life Span 25yrs Haofeng Poly Panel Solar TEST CONDITION TEST CONDITIONS :1000w,AM1.5,25°C ... Parameters typeHF-M15-18 Polycrystalline solar panel 20WMaximum power (watt) W20WProduction tolerance +3% /-3%Maximum power voltage ... ,10years 90% and 20yesr 85% of the power HF 20W poly panel solar