[osigurdson]

In cold climates, EVs should absolutely include a propane tank to generate passenger heat and bring the battery into its proper operating range. Generating high entropy heat with low entropy electricity from a battery offends my sensibilities.

[audunw]

Most modern EVs have heat pumps. Not using heat pumps to generate heat - exploiting the larger than 100% efficiency you get in the process - offends my sensibilities.

If we have propane, and want to use it for energy/heating, it’d be better to burn it at some large central efficient generator (perhaps supplying waste heat as district heating for nearby homes), and use the electricity to power heat pumps.

[osigurdson]

At -40C, the COP is only going to be 1.4. A natural gas fired cogen plant is 60% efficient so even without transmission losses this ultra complex arrangement is not more efficient at generating heat.

You are conflating the efficiency of generating mechanical energy (where such arguments hold) with generating heat.

[bawolff]

Don't heat pumps stop working around -25C? That is obviously not going to be effective in alberta. (Current temp -36C [not including windchill])

[FredPret]

The windchill actually only affects humans - moist skin cools down faster in the wind.

But -36 is enough to bring down heat pump efficiency a lot.

This site [1] talks about heat pumps that work down to -30. Not good enough to trust your life to if you’re an Albertan.

[1] https://www.bchydro.com/news/conservation/2022/cold-weather-...

[kevin_nisbet]

> Not good enough to trust your life to if you’re an Albertan.

I believe the heat pumps intended for these climates provided alternatives for those cold days. If you want to stay all electric, it would include a resistive electric heater, but could be paired with some other fuel source.

Personally, I'd seriously consider going ground source where temperatures like this are the norm, but that doesn't work for everyone either.

[bawolff]

That may work for your house, but it really doesn't make sense for the emergency heat source of your vehicle to also need an emergency heat source.

[bilsbie]

It could just be a secondary battery with cold compatible chemistry with just enough energy to warm up the main battery.

[osigurdson]

A 20lb propane tank is a 100 kWh battery (if only generating heat).

[pxeboot]

> In cold climates, EVs should absolutely include a propane tank to generate passenger heat

I believe some EV buses are heated with propane or heating oil, so it would probably be feasible to add to personal vehicles as well.

[declan_roberts]

As someone that drives an EV in cold weather, a propane tank for heat would be a huge improvement.

[cwillu]

As long as you don't want to ever make use of underground parking.

[speedgoose]

Good EVs can heat up their battery pretty fast using only electricity.

I know someone who was using a diesel heater in its Mitsubishi I-miev, an old EV that had a terrible factory heating system. It did sound a lot less convenient than electric heating.

[johnwalkr]

Absolutely? Maybe adding a propane tank, the systems to use propane to heat the passenger compartment and battery safely, the complexity refuel it, the extra mass, the extra maintenance, being banned from some underground parking...

I get your sensibilities to be efficient but I think overall it's not efficient or a great idea to add propane and propane accessories to EVs.

[swader999]

Propane freezes at about - 38.

[Plasmoid]

Liquefies. It's almost impossible to use at that temp though because you burn propane gas.

[osigurdson]

Works in propane powered cars down to -40C.

https://propane.ca/for-my-business/auto-propane/#:~:text=Exc....