New Amp concept or already there?

True, you would have to have multiple stacks with proper voltages since DC/DC conversion involves RF noise...

Battery bank with multiple voltage outputs. Solid state amps use collector voltages ranging from 12 to 65V which is achievable today. 

hard way to accomplish an alreay solved problem...you have a solution in search of a problem.

The problem is these Tesla power wall grids is over $10k in my area

i on in a great area near the power station , I use awg 10 Copper , had it Cryo treated in my city MA. What’s special all Pangea top gold over Copper $100 each 

a Siemens whole house surge power at the breaker, + Vh Audio dedicated to just this 20 amp circuit that does much more then surge $900

a 4 wire dual ground 1 common ground ,the other a insulated isolated ground on its on buzz Bar then grounded ,breaker ,highly recommended to change 4-5 years . I was fortunate to get Silver plated copper breakers which were $45 each from Siemens Germany got in 21 since covid the industrial warehouse can no longer get.Furutech power block ,  Money well spent IMO. 

Vinnie Rosse REd Wine audio and I remember another brand used to make amps with batteries before lithium and sounded pretty good .