[jyl]

Yeah, I wonder. 11 years is 4,000 daily charge-discharge cycles.

I have downloaded my hourly use for a full year, and can model out exactly what kWh battery I need to be at 80% or 95% off-peak buying.

But I need to get a sense what the systems cost. If my guess above is way low, then it’s pointless to do this work.

The main reason I got interested in this is that I see our electricity rates going up at a too-high rate in the coming decade.

Nationally, the electric power grid - distribution, transmission, generation - needs a metric f-ton of investment. Something like 50% of the lines are at or near end of life. Power demand was flat for some years, but is now growing 2-3% a year - thank you, artificial intelligence and all the AI data centers being built that need city-level amounts of power 24/7 with perfect reliability. Something like $200 billion a year being invested in the national power system and that is nowhere near enough. Add wildfires out West which are forcing big investment to underground transmission lines.

The normal way this investment is funded is the utility companies get state permission to invest $X billion and make a return on that investment by raising rates. So everyone has to pay for Google or Microsoft to get enough power for their new datacenters. I’d think the companies should pay but they’ll make sure their friends in high places kill that idea.

If I run my model with power rates rising +7% year, the payback looks better.