Much like insulation they help, and I would wager its cost effective in most places most of the time, in particular for individuals. But I am not sure how well

Much like insulation they help, and I would wager its cost effective in most places most of the time, in particular for individuals. But I am not sure how well it scales. Compare building and installing 5 million heatpumps with building 2GW new nuclear power production ? The latter could include at least one city heated entirely by cooling water, but even ignoring that, using Finnish numbers for nuclear, and ballparking optimistically the heaters? They cost about the same, take about the same time to build and install... its unclear to me which would lower individual costs more, which would be better for the economy, or climate. I guess heatpumps win on individual costs, nuclear on the economy, and both being roughly equal on climate. The nuclear plant certainly wins on total maintenance resources/work, but the heatpumps on versatility of maintenance, i.e. you can just say fuck it with heat pump maintenance in a way you cant with nuclear. Nuclear wins on flexibility, while heatpumps win on rollout, giving its highest benefits very quickly, but taking as, if not far longer, to complete. There is often a benefit to mass production over individual small scale stuff though. If we could build at 1970ties + inflation prices though, the nuclear plant power would cost less than a tenth, and output more power than the total heating the corresponding 500k heat pumps provide. Compare to how people buying and installing large supplemental home solar+lithium ion battery packs looks great, until you consider the cost and time to deploy a million such, and compare that to the cost and speed by which we could produce a large hydropower dam as energy storage. The latter wins by a landslide, or occasionally flood^^. Heatpumps are much better and cheaper, though, so its harder to tell.