I have a 7.29 kW system I was thinking about getting a battery to add to my solar panels. My main thing is I want a zero bill all year round. And to be able to use without worrying. This summer the July bill was $88 for electricity. If in the winter it will produce less and my consumption matches the production than I assume I will be getting a bill? But the thing is for July it never showed I used the grid in the Enphase app. The only thing I can think of is that at night when the AC(central air) was on it was using from the grid. (I did see some credit from what I remember 200 minus 800 used I am not sure but the difference made it $88 bill). Is it worth getting a battery? If so from anyones experience is the power wall the choice or stick with Enphase? On YouTube everyone seems biased (salesman) Forgot to mention I have 2 Tesla's that I charge at home. Also have two chargers and 200amp Thanks