Depends on the area and many other factors, e.g. how the electricity is generated. In much of the northern US/south eastern Canada, electric heating is much more expensive and less efficient overall.
Natural gas heating is less than 100% efficient (if a new furnace maybe in the area of 80%), and causes global warming.
>Power generation itself and transmission
is separate from the efficiency of the heating process, which is 100% efficient.
Unless your power is generated by coal, in which case you’re even better off using natural gas.
So yes, I agree, but heat pumps have cold weather limitations that mean they only benefit relatively warm climates.
Also, I've never seen a building (in the U.S.) that relies on electric heating if temps in the area will get much below 10°F (-12°C). At that point, it's always natgas/propane/fuel oil/wood.
But the heat pump has a "outside" part, where there is a fan and other electrify using stuff. Can you not risk that more heat is generated outside than is moved inside?
Sadly I've seen many buildings (apartments and homes) that use electric baseboard heaters, and you probably have as well. They just aren't very modern.
Keep the house at 66, heat one room at a time to 70.
From my own energy monitoring applications, I recon about 40% of my winter heating needs are met in this manner. I DO use a heat pump for heating between 40°F-60°F, but the efficiency of such a device rapidly diminishes as the temperature falls below freezing. Below 20°F, an average heat pump begins to be LESS efficient than simple resistive heating.
Mitsubishi's residential air-source ductless mini-split heat pumps that have their "Hyper-heating inverter" technology, and similar systems from Fujitsu, are still about twice as efficient as electrical resistance heating down to around 0℉. They don’t start getting beat by resistance heating until around -15℉.
Their capacity starts dropping at around 23℉ and would be around 75% at -15℉ so if you need to go below 23℉ you do have to oversize your system.