Yes, the colder the air is, the less efficient a heat pump is. My 10 year old heat pump has a COP of 3 but shuts off at -15C because below that it's less effici

Yes, the colder the air is, the less efficient a heat pump is. My 10 year old heat pump has a COP of 3 but shuts off at -15C because below that it's less efficient than an electric baseboard heater. Newer air-to-air heat pumps have a COP of 4 or higher so they can handle down to -20C or -25C. I keep my EBBs set to come on a few degrees below where I keep the house so they will kick in when the heat pump shuts off and they kick out when the heat pump comes back on. This tends to happen at night when I don't mind the house getting a bit cooler anyway. Where I live in Canada, the heat pump typically only shuts off half a dozen nights in the second half of January. It's not like my heat pump is useless 6 or 8 months of the year. There are also geothermal heat pumps that push/pull heat to/from water from underground (eg. a well, a pond, or a buried coil of pipe) where, even in the winter, the ground remains warm. These don't suffer a loss in efficiency in the winter. Regarding EVs, most EVs get between 3 and 4 miles/kWh. The Porsche Taycan gets only 2 miles/kWh. The Tesla Model 3 gets 5 miles/kWh. The Aptera gets 10 miles/kWh, which with the 100 kWh battery, gives you 1,000 miles of range. Fully Charged Show - Aptera (time-indexed to efficiency discussion): https://youtu.be/mpiH-Y-HOvE?t=135 https://youtu.be/mpiH-Y-HOvE?t=135