this post was submitted on 17 Jan 2024
352 points (97.3% liked)
Technology
58011 readers
2930 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related content.
- Be excellent to each another!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, to ask if your bot can be added please contact us.
- Check for duplicates before posting, duplicates may be removed
Approved Bots
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
How is this gonna work when electric cars won't even run in icy weather
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.
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
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.
"How is this gonna work when I have no fucking clue what I'm talking about"
Yeah. About that. Go read a bit about electric cars instead of scare headlines in the news. Hell try one for yourself, you might like it.
Look at this guy, who has never had to start a diesel engine when it's -20°F outside.
Shit, they're hard to start when it's + 20°F outside. I'm a school bus driver and that was the exact temperature this morning when one third of our fleet wouldn't start up.
https://stnonline.com/partner-updates/6-myths-about-electric-school-buses-debunked/
"...according to a 2013 SAE study, the average school bus route is less than 32 miles, with over 99% of routes being under 78 miles. "
Busses exist with a 155 mile range. This is a non issue.
I grew up and rode the bus to school in Iowa. There were multiple days in my youth that local schools were closed because the diesel busses wouldn't turn over. The guy that maintained ours used Amsoil, so our buses worked, but cold weather doesn't only hurt electric vehicles.
There were reports over this past week over people having difficulties charging their electric vehicles due to the cold temps (-30°F wind chill and worse). All of the schools in the state were closed as well as many businesses.
Basically, it's a self correcting issue. If it's too cold to charge a battery, it's too cold to have school.
I rode the bus in Alaska. The buses ran well below -50f. It turns out that it's not that hard to keep your batteries and oilpans heated if you bother putting plug-in heaters (literally, electric blankets for the purpose) in your fleet vehicles, winterize your vehicles, and plug them in when it's cold.
I get that it's uncommon to be that cold-prepared in places that don't expect to see temperatures below -20 for more than a few days in a given calendar year- at some point, it makes sense to just call it off when it's that cold. After all, do all (or even most of) the kids have proper clothes to deal with real cold?
Really cold weather can be adapted to, it's just that when you don't need it that often it makes sense not to spend the resources doing it.
For sure. The ROI really isn't there when it happens every couple of years. Like you said, they do call it off when it's that cold. It's not safe for kids that have to walk to the bus or school. The main thing is that electric is the same way, so it's a moot point.
No, the larger point is that it's a struggle to make diesel work at +20F if you don't do the things to make it work, and yet these things can be made to work reliably at -50F. The obstacle isn't the limitations of the technology, it's whether or not the cost curve makes sense. Electric can be made to work cheaply, if it's important to you that it work- just like it's possible to make that diesel turn over at -50F
When I say electric is the same way, I mean that if it's too cold to run the vehicle, it's too cold to have school.
Ok, that's fair. The point I wanted to make upthread was that these sorts of impossible things are regularly made to work when making it work is worthwhile. Most of the 'but this is a limitation of the technology' talk here (about how EVs can't work in the cold, etc) is defeatist bullshit that ignores that really if you want it to work it can be made to work
A combination of heaters and being mostly deployed in warmer environments, I'd assume.
Most schools don't open when is icy or extremely cold out. So your point is useless.