[matthiasl]

> Electric heat pumps actually don't work in very cold weather.

I think that statement needs to be qualified and quantified.

Qualified: your claim is probably only intended to apply to air-source heat pumps, not ground-source heat pumps. Ground-source heat pumps are popular in places with cold weather, for instance Sweden.

Quantified: If you mean -40°C, then, yes, air-source heat pumps aren't going to work. But most people don't live in places that cold, and just because we can't use air-source heat pumps in a few places doesn't mean they're useless everywhere. Here's a data sheet for a relatively cheap air-source heat pump that's rated to work down to -25°C (about -14 F):

https://img.polarpumpen.se/pfiles/fujitsu-km-slim-09-12-14-p...

[nightski]

They aren't readily available in the U.S. and even if you could buy it online or something no local place tends to service them. This is a generalization, so I am sure there are exceptions but it seems to be the case in most places I've seen.

As far as ground sourced those are significantly more expensive. The cost/benefit is not there unless the only factor in your purchase is climate change.

[midoridensha]

Yeah, this is what I was referring to. The heat pumps available in the US only seem to work down to freezing (0C). After that, they just turn on resistive heating, which is very inefficient.