One note on energy in nat gas: that assumes 100% efficient gas furnace. Cheaper furnaces are ~80% efficiency. Really good furnaces are ~95% efficiency. Adding

One note on energy in nat gas: that assumes 100% efficient gas furnace. Cheaper furnaces are ~80% efficiency. Really good furnaces are ~95% efficiency. Adding natural gas infrastructure to a building that does not currently have any is extremely expensive, even if the natgas furnaces aren't particularly expensive themselves. I agree it's cheaper if you have it now, but that assumes you already have a gas furnace. I think the fear for most people is that natural gas can easily become substantially more expensive. European natural gas pricing is currently ~$20/mcf, and spiked to ~$80/mcf for some time. Natural gas pricing limits you to a single source for power... whereas power inherently has many sources it can come from. If natural gas becomes more expensive... you're stuck paying more with the furnace. With heat pumps, there's options available to alleviate pricing either for producers or for consumers (namely, solar for consumers). Also, importantly on the COP point: you need to talk about the area under the curve in terms of cost. Although it may be more expensive per unit of heat when COP drops below ~3, you have to think about it in terms of overall cost. A furnace will be the same efficiency if it's -50F or if it's 50F outside (for the most part...). So for the periods when it's mild, but heating is still required, the heat pump is an obvious winner. I suspect that the math works out in favor of heat pumps, even with reduced efficiency during winter, for many climates. The only thing is that you'll get a much more peaky power bill. Obviously there's exceptions, but there's vast swaths of the world where a heat pump is going to make a ton of sense.