[derekp7]

I was wondering what the overall efficiency would be if you still used gas, but had that gas power a combustion engine to drive the heat pump compressor, while also reclaiming the heat from the engine and exhaust? Would that be more efficient than burning gas at a peaker plant to convert to electricity to run the heat pump?

[ct0]

Seems like this exists for non single family home applications. https://www.yanmar.com/global/energy/ghp/vrf/merits.html