Heat pumps twice as efficient as fossil fuel systems in cold weather, study finds
Doubts about whether heat pumps work well in subzero conditions shown to be unfounded, say researchers
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A sticking point I encountered - the drop in efficiency as the weather gets colder means you need a unit sized to heat your home on the coldest days you expect to encounter. So you need to buy a heat pump that's larger than you need for 98% of the year just so you don't freeze that other 2%. In addition to higher cost an oversized unit is less efficient because it's cycling more.
So this is where "heating strips" or "backup heating" come in, and then I get we've come full-circle.
I don't see how this is "full circle". In places where it does get that cold, most homes already have a form of heating for the house. Adding on a heat pump or, at least in my case in the Midwest, replacing the central AC unit with a heat pump just means that you're only kicking that original heating system on a few days out of the year. That's a massive reduction in use compared to being the only source of heat for half the year.
It's a problem that new construction homes would need to fix if they don't want an NG connection at all, but it's not unsolvable.
You'd usually run two or more units in a cascade/multiplex when requiring large amounts of power rather than having one giant unit. Means you can turn off one or more units entirely for low heating demand.
Also choosing a unit (or units) that use a speed controlled compressor will limit cycling as they can ramp for the actual load.
I think modern inverter units are not less efficient when oversized. They are able to run at varying levels rather than cycling.
Those "heating strips" are only used a few weeks every year in my case.
The optimal solution is to add a small heatpump in addition to a gas heating