There is no convincing technical reason why heat pumps cannot be widely used in all European climates.

And their potential may even be greater than previously assumed by their biggest fans. (Dad pun intended)

https://www.cell.com/joule/fulltext/S2542-4351(23)00351-3

An unrelated project surveyed 710 homeowners who recently installed a heat pump: comfort improved in 81% of cases and decreased only in 1%.

Ten to twenty households were interviewed in 22 countries: 20 EU member states and Norway and UK.

https://www.coolproducts.eu/wp-content/uploads/2022/02/EEB-Heat-Pump-Comfort-Audit-Report.pdf

Finally: these data only show high efficiency. What about comfort?

In one of the US studies, 32 of the 42 cases reported being ‘very satisfied’ with their heat pump in the past year. 10 respondents noted “improved comfort and temperature maintenance”.

https://e4thefuture.org/deep-dive-research-heat-pump-building-electrification/

Below these conditions, a standard heat pump can still provide almost all the heating load.

But on the coldest days, either a cold-climate heat pump may be appropriate, or some form of back-up heating to boost the heat pump such as a pellet boiler or green gas boiler.

So when is back-up heating actually needed?

Our view is that in climates where the temperatures rarely fall below -10°C, standard heat pumps can comfortably provide full heating.

I'm excited about this research because I hope it helps put to rest the claim that heat pumps don't work in the cold. They do.

With a suitable device selected (e.g. cold-climate or not), proper sizing, and high-quality installation, they can provide efficient winter heat.