The Tesla system (I think they’re represented by Solar City) might be organized a little bit differently. They might be able to tie directly to the Tesla batteries.
However, my assumption would be that the battery wall or Tesla system would still be charged directly from the utility side and then provide the power backup locally during a power outage similar to conventional smaller UPS. I don’t know if they can be charged directly from solar panels during a power outage.
For us, a generator makes more sense considering the cost of the battery panels needed and the few outages we actually see. Plus, I haven’t seen battery technology that’s good for more than 8-10 years. 5-8 years is the replacement plan for batteries (90+ deep cycle marine batteries at each site) to maintain public safety radio sites I maintained up until last November. Maybe Tesla claims are better.
I’ve been told by every solar company we interviewed that were forced to use Excel’s net metering system. The solar energy we generate goes straight out to the utility grid through a meter that measures that generated energy as well as the energy consumed. The energy generated is “banked”. Meaning, if we’re generating more than we use, it goes to a credit on our account. During the winter when we’re likely to generate less than we use, we can draw on the “banked” energy.
We pay the difference or, for future home owners who aren’t going to have an industrial aquatics facility in the basement, they should receive a check from Excel.