My utility company (Florida Power and Light) does not technically buy back electric (at least not at retail pricing) but they do credit me 11months of the year for any overage. I have an 11.69kw solar array and my bill goes from $20-$100/month. Any extra power made from Jan-Nov gets traded back and forth evenly as credit on my bill (no actual money is provided to me). So if I made 20kWh extra this month and used 20kWh the following month I would essentially own nothing. It gets balanced out each month and then at the end of December anything extra I have leftover (which I wouldn't have) would be bought back from me at wholesale pricing. They would send me a check. I think it's like 3 cents a kW. Since any extra power I use goes into a credit status from month to month would having a power wall actually save me any money? The only advantage I can see is having battery backup. It would seem logical that any solar power we generate that charges the battery in the power wall would take away from the power we send back to the grid. This would essentially be a wash. If it took 10kWh to charge the batter back up that would be 10kWh less power going back to FPL. Right? I think I would need to buy at least 2 Powerwalls to run my house as well so it would be pricey. We have 200amp service and our panel is maxed out. We only have one 50amp circuit to charge both our Teslas. I am sure I used some wrong terminology in this posting but I think I gave enough for you to understand the heart of my question.