I’ve never heard a claim that heat pumps won’t work well in a climate like San Francisco and, from looking at the annual temperature patterns, it seems like both air source and ground source heat pumps should work extremely well as they do in the “shoulder seasons” here in New England.

> pv in the UK doesn't work

tell that to 6% of UK electric production https://www.bbc.com/news/articles/cz947djd3d3o (up from 5% in 2024

Heat pumps have gotten a lot better, you need a pretty extreme climate for them to start to struggle, even the air-source ones.

(And PV works well enough in the UK for it to be a no-brainer to put on residentials roofs, which is on the whole the most expensive way to deploy it. Though this is in large part due to the way that it competes with retail prices and not wholesale prices)

Wait Minneapolis is definitely very cold for about half the year.