300L Endurable High Quality China Solar Energy Water Heater

300L Endurable High quality China Solar Energy Water HeaterFeature:1)The 1st Solar PV DC water heater in the world2)Combination with highest quality electrical water heater+Solar PV panel3)DC72V+AC220V sametimeAC power just a back up,even in winter nearly no need electricity4)2 grade higher than the best water heater standard on Energy consumption and heating insulationeach 24 hours temperature loss less than 8degree!5) 10 years warranty6)Nearly no need grid power in winter only with 400w-600w solar panel for different area.7)Effiency Data : 2 level  better than the best top standard .24H Intrinsic energy consumption coefficient only 0.46.  Intrinsic energy consumption coefficient Level 1