Southern Europe is different story.
Heat pumps are very cost effective and me and most other homeowners I know have, over the last couple of decades, completely migrated from wood to heat pumps. In fact, there might not be that many homes who'd convert left to convert.
The House construction locally has definitely tanked this last year. Much fewer projects.
My thermodynamics class is some time ago, but pumping the heat stored in arctic air to a sufficiently high level for residential heating sounds indeed like an electric heating effectively.
I think air heat pumps are more common due to their low price. They are easy to install and work well as a complement to other heat sources.
Geothermal is popular too, but the installation cost is significantly higher.
I come from rural-ish Norway and live in a big city in Germany. Lots of people here in Germany are quite willing to tell me that heat pumps don't work in the area where I come from, where I have many friends with heat pumps. Their confidence amazes me. I don't understand how they can be so confident.
So everybody has been telling everybody in Germany that "electric heating" doesn't work, heat pumps are vaguely "electric heating" (different mode of operation, but for that you'd have to know how heat pumps work in the first place), and with all that you end up with some "wisdom of the crowd" that fuels false confidence.
Why is this? Isn't electric heating (in the space heater context) by definition 100% efficient, because all of the energy is translated into heat (with the light as a byproduct)?
In the large: That idea is from a time when burning fossils at home (including coal) was the way to heat, and burning fossils to drive a (relatively inefficient, at least compared to today, and filters were an unknown luxury) generator was the way to create electricity.
You likely got more heat at home out of a bucket of coal when burning it at home rather than burning it at the power plant (with some excess heat there), converting it to electricity (with some losses), transporting electricity home (with some losses) and then heat up the home with that, even with 100% efficiency at that last step.
(These days I wouldn't be so sure: those power plants, even the fossil burning type, are fine tuned high-tech at a level you can't just put in ordinary homes, so they might actually extract more energy to use after all the losses along the chain than the fireplace at home that evicts a considerable percentage of the heat through the chimney)
https://www.euronews.com/green/2023/10/30/do-heat-pumps-work...
I'm in a house in Germany and got it converted from gas to heat pump a couple of years ago. It took some adaptations to make that work, but on the flip side we obviously blasted lots of heat into the atmosphere before, which we're reigning in now (still work in progress).
So yeah, conversions of houses not built to "heat pump spec" has follow-on efforts and costs that the heat pump hype didn't advertise. I had a rough idea what to expect and that it'll take a while to sort out everything, but if you went into the conversion with the idea that you're just replacing one part with another, you're in for disappointment.
https://www.ecohome.net/guides/1401/new-brunswicks-most-ener...
My grandma's house from the 1950's wasn't "designed for heat pumps", neither my other grandma's house from 1940. Neither was my mother in laws from the same period.
You don't need to design anything, you just need a hole in the wall to run the cables.
What does make the houses suited for heat pumps is the fact that Nordic houses are designed to keep the weather out. So when you heat/cool the inside, the house doesn't leak it all outside.
Alright, my bad. Consider "designed" replaced by "suitable".
Houses of a certain era in large parts of Germany (those with only a few days of moderate sub-zero temperatures) tend to have been built with a bit of air leakage capacity to avoid mold. Yes, that's wasteful, but since fossils were (and are) subsidized like crazy, you just heat a bit more and be over with it.
That strategy doesn't work as well when you have less heat to work with.
There are still people who argue that it's unhealthy to live in a properly insulated house ¯\_(ツ)_/¯. I doubt you have a lot of that nonsense in areas that deal with freezing temperatures for months at a time.
I have a gas boiler -radiator piping built into the walls and people I talk to say the radiators wont work with heat pump level of temperatures so as in your case the system needs to be converted but how. What are methods and techniques?
The inbound temperature into the radiator network took a dive from about 70°C to about 40°C here (I _could_ push the inbound temp to nearly 50°C but by then I'm no better off than with resistive heating), and that's rather obvious when heating the rooms.
The main advice everything came down to was "have a lot of surface that can heat" and from my experience that seems to be quite true.
The house has a bunch of radiators that never ran in the nat-gas days, basically it was overcommitted on heating surface. Now they're pretty well used. Another retrofit option that I had in the back of my head was radiators equipped with a fan to move the air along the radiator surface more quickly (essentially creating "virtual heating surface"), but I didn't need those.
Other than that, warm and cold parts of the house (e.g. basement) are more clearly separated. A FLIR camera module for my phone gave some hints on where heat escapes so that I could focus on the right spots.
When a larger rework of a room is due (and there's a huge mess in any case), that's a chance to look into floor or wall heating there, connected to the same system.
Once that's (mostly) done, I suppose the inbound temperature can be reduced some more, and I expect super-linear electricity savings from that (due to the way the heat pump works).
In terms of costs, it comes out at about the same, although there are more options in electricity availability, and I suspect that pricing there remains more stable than with fossil fuels, so longer-term I expect operating costs to develop beneficially (even if that only means "remains flat"). TCO of the project, I don't know, but I was optimizing for long-term OpEx for various reasons.
By the way: Heating engineers tended to dismiss the project, but the project started before there were any issues with gas supply, so "just use gas" was their go-to solution anyway (for the eco-conscious, they dangled the carrot of "it's H2 ready!", even though it's unlikely that the pipe work will ever support that). Not sure if the attitude of heating engineers changed in the meantime.
In the end it was done by air conditioning technicians, and it can be switched between heating mode using radiators and AC with split system frontends, so this house covers cold winters and hot summers with just one external device (which pleases the historical landmark office)
That's not what I've heard of even air, but to be clear, you are talking air source right? I'm near the Canadian border in northern New England and am getting ready at work to have another vertical ground source (geothermal) heat pump put in, and those are very effective year round. Well loop is around 515' (~155m), which is on the longer side but not a big deal by well drilling standards (which is why lots of well drilling companies have been expanding into heat pumps in the last 5 years and availability has sky rocketed). The price is definitely much higher than air source for now, maybe always will carry some premium, but the major government incentives here help significantly and of course the reliability is high. There are a few minor other bonuses as well I guess, like aesthetically speaking once done there can be nothing to near nothing visible outside.
There are a few other strategies (horizontal ground, water source, semi-open) that some are looking at too but around here simple vertical closed looks likely to end up as the majority due to economies of scale, it can be done anywhere vs needing more/special land, and like I said leverages an existing industry. It's neat to see coming along, so perhaps longer term that'll offer an option in Northern Europe too.