Heat pumps are mostly useless when it is minus -20 C. Diesel heater is the most practical solution. Sodium or LMFP batteries will help, but even with them the range reduction in winter due to the need for heating and increased drag from cold air is just too great.

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wcoenen an hour ago | parent | next [-]

> Heat pumps are mostly useless when it is minus -20 C.

Two-thirds of households in Norway are heated by heat-pump, so I don't think that can be true.

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yalok an hour ago | parent | prev [-]

diesel fuel itself needs to be heated at -20 C and below. I used to have a diesel car which would start itself up periodically when its fuel temp was getting close to -20 C, just to warm up the tank & pipes.

	▲	eichin 31 minutes ago \| parent [-]
		Yeah, the 1999 diesel truck I had did the entirely opposite thing: it had a 120v electric block heater, so you'd plug it in when it was cold. (In New England, I used it once to see how it worked, but never actually needed it in practice.) At the time I saw stories (I never confirmed in any depth though) that Minnesota had 120v outlets on parking meters, giving some sort of weather-encouraged compliance :-)