6)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<=0.6;Level 2<=0.7;Level3<=0.8;Level 4<=0.9;Level5<=1;

Hotwater output rate is as high as 94.8%; the highest level 1,is only more than 70%.level 2 should be more than 60%.

Power consumption is only half of traditional electrical waterheater if only use grid power .