[enslavedrobot]

The advance would come from building systems that can scavenge waste heat from multiple sources instead of just exchanging with outside air.

The model Y introduced the "octovalve" which regulates flow in 13 different configurations to bring the highest quality heat to the cars heat pump.

In a house this might be something like extracting heat from grey water, or even cold tap water, ports for a solar heated loop, fresh air exchange etc.

System integration enabling efficient use of heat transfer is the opportunity

The Tesla heat pump also introduced high volume low cost manufacturing processes like semisolid aluminum casting and friction stir welding. That promise to lower costs.

Another thing that is potentially achievable with a low cost integrated approach is staged heat pumps for hot water tanks.

The possibilities are endless really, at the limit these ideas lead to integrated neighborhood scale heat networks tied to rooftop solar that can replicate district heating strategies.

Lots to be done.

[rsynnott]

… I mean, again, that all pretty much exists (except maybe the thermal solar stuff, but PV ate thermal solar’s lunch about 20 years ago). Any new home built here at this point will generally have a heat pump with MHRV, which heats the hot water.

Generally the major cost in retrofitting such a thing isn’t the unit; it’s the modifications to the home to support it.