off grid power system ISO9001,ISO140001,ISO18000,TUV,CE and Gold Sun certification 1. ... brightness, Solar street lamp, Off-grid PV power system, On-grid PV power system etc..2. Qualified certification: ISO9001,ISO140001,ISO18000,TUV ... years for whole unit5. Lifetime: Twenty-five years6. Servive: Field installation and debugging guidance by professional engineer