this post was submitted on 17 Jan 2024
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Electric cars run just fine in icy weather
Heatpumps, which work a lot better for larger buses than smaller buses.
Bus routes are generally short, fixed, and planned. They are literally the perfect place for an EV.
You can generate a lot of heat with fuel-based heaters. Many buses already use these.
Makes sense to have an aux fuel heat source for EV buses that may deal with cold climate a few weeks out of the year.
Buses will have fairly large batteries (Bird does 150kWh). The percentage of the battery needed for heat goes down as size goes up because the interior size is relatively negligible in how much added heating capacity is needed to keep the bus warm.
But yes, probably wouldn't be too crazy to throw on a propane heater in especially cold climates.
3 kids in a full size bus near the end of its rural route in sub-zero conditions. Buses aren’t insulated. An EV failure is going to be a problem. Considering how cheap those diesel heaters are it would be a liability concern to not have them.
https://www.nrel.gov/docs/fy14osti/60068.pdf
"Similarly to route duration, doubling the route distance to reflect daily operating distances, it is found that on average school buses travel 73.46 miles, with a 99.7% cutoff on driving distance of 154.46 miles."
That's double distance to cover both before and after school; they have a pause in the middle of the day to charge up again. There are battery buses on the market right now that do 155 miles, which is double all but 0.3% of routes out there. It also takes about an order of magnitude more power to run a motor for an EV than it does to run the heaters. If you get stuck in the snow in an EV at 50% charge, you can likely make it there through the night with the heater running.
The cold is a complete non-issue for this use case.
Why. I mean if the weather is usually fine sure but if you're living on the arctic circle they better be insulated.
AAA says that EV batteries tend to lose power faster in cold weather, getting as little as 50-60% of their advertised range.
"Charging stations around the city are over capacity... Once their car is finally plugged in, it takes longer than usual to power up. “...They tell you it’s fast, but then it takes two hours to charge your car,” Marcus Campbell tells NBC Chicago."
https://www.pcmag.com/news/dont-buy-a-tesla-chicagos-ev-drivers-struggle-with-sub-zero-temperatures
This weather is a worst case scenario and I doubt schools would be open anyway but sounds like EVs are having a tough time.
Right, and the EVs that lose that much range are the ones with the smallest battery packs. The heating requirement as a percentage of the battery pack goes down as the battery gets larger. It takes roughly the same amount of energy to keep a 40kWh battery warm as it does to keep a 150kWh battery warm.
The same logic doesn't directly translate for a car as a bus.
Don't buy a battery only car if you don't have a place to charge it. But that's totally irrelevant to school busses.
They wouldn't use public chargers you buffoon.
School busses are used like 4 hours per day, so that leaves 20 hours per day for charging.
99% of School busses need to drive less than 156 miles per day.
School busses drive slowly, another thing well suited to electrification.
Honestly lithium batteries are probably totally unneeded here. Something swappable? A cheaper lower performance battery could be used and charged or swapped during the 6 hours the kids are at school. Charging speed could be actively managed to help level grid load e.g charge overnight, but not during peak usage times.
I was replying to a post that started with: "1. Electric cars run just fine in icy weather"
Just fuck off with the name calling