Grid-level battery is unworkable nonsense that Musk sells and I suspect some states might force the taxpayers to pay for.
I follow Alex Epstein on Twitter and he says Musk is lying his ass off. Alex is already called a “science denialist”. Will he still be allowed to post on Twitter after Musk owns it?
https://twitter.com/AlexEpstein
But if Musk is saying grid-level battery helps smooth the power (getting rid of what electricians call "dirty power") then he's got my attention.
The power coming through my inverter from battery is cleaner than when my inverter has to pull from the grid (because my batteries are discharged and my solar isn't creating enough power for my house's needs). I can see something good coming from a large battery at power relay stations -- but that's to smooth the power not to replace dependency on fossil fuels.
I'm a yuge proponent on decentralized solar power done completely voluntarily. If you live in the southern half of the U.S., own your home and plan to be there at least 10 years, have a metal roof (assuming you'd put the panels on the roof), and a way to mount most or all panels facing south, then solar will pay for itself on about the 10th year and free part of your budget from energy inflation. (My fixed cost of installing solar is being paid through making payments on the HELOC loan I took out to pay for it, now my power bill is small and I no longer have a natural gas bill because I converted my 2 natural gas appliances to high efficiency electric ones. The end result is that the small power bill is the only part of my home energy budget that is susceptible to rising with energy inflation. My HELOC payment with a fixed interest rate won't go up.) But that works only if you do your homework ahead of time, study your power bills each month throughout the year, the average peak solar hours you get at your zip code each month, the angle of your south facing roof, etc.