My whole house generator runs on natural gas. Indiana natural supply gas is stable and afaik never stopped in the last 20 years. It automatically fires up 6 seconds after power goes out and runs my entire house including EV charger. It’s fairly quiet, cannot hear with windows closed.

Cost like 5k and 2K install. Really hard to beat that in the near term with battery.

No it doesn’t do the demand shift part of a battery, but it’s pretty clearly better as an emergency solution, at least for my needs.