A giant battery gives this new school bus a 300-mile range | Hacker News Reader

A giant battery gives this new school bus a 300-mile range

arstechnica.com

24 pointsrbanffy9 comments

The Soviet Union built schools in every village instead (even if it meant a school for just two students), and built villages around "advanced" schools where the interested students could relocate, thus making such buses mostly unnecessary.

The idea that there would be enough teachers or that society would value them enough to pay a decent wage seems increasingly unlikely where I am (New Zealand).

That said, the state wouldn’t fund the busses either, so there isn’t any hypocrisy to see here.

Pollution from diesel fueled school busses almost certainly impacts urban kids more than rural ones, so urban districts with shorter routes and lots of stops would be the logical first step for electrification. I don't know what the price premium for the super long range electric bus is but it certainly significant. Hopefully the funding for replacing diesel with electric is made available in a way that benefits the maximum number of people.

I remember riding to school in a smoke belching 2-stroke diesel bus. It sounded (and smelled) distinctly different from our modern diesel technology. I'd like to experience a new electric bus. Maybe I can volunteer to chaperone Science Olympiad again.

How about a smaller battery, but put trolleybus power lines above the road? This is pretty much the only realistic way large vehicles will function as electric.

Why would that be the only realistic way? Larger vehicles have more space for more battery capacity, and for stuff like school buses they don’t tend to go super far distances. I don’t know why it’d be a problem. The 300mi seems excessive honestly.

It's not an issue of space, but one of mass. Tesla's newest batteries are supposedly around 270-300 Wh/kg. 5 tons of these batteries would give you 1500 kWh of energy.

Compare this to diesel that has an energy density of 12,640 Wh/kg. Diesel engines are less efficient, but you would still save multiple extra tons in weight for the same distance traveled, which would increase your distance traveled further.

Electric buses do work, but the more batteries you cram in there the more extra weight you have to pull around at all times.

I fail to see the issue here. School buses have ample space underneath them to store the batteries. Sure you have to account for the extra weight, but just like electric cars the efficiency of the electric motor in a bus is plenty to overcome the difference in power density of the 'fuel' source. Also, given school buses tend to do a lot of stop-and-go, and travel at lower speeds, this is essentially the ideal conditions for an EV.

> The 300mi seems excessive honestly.

Indeed. Are schoolbuses doing multi-100 mile trips on their route? If so, those kids spend like >1h one-way (so >2h every weekday) riding in schoolbus?

Ok. I understand the benefit of shallow (dis)charge cycles. Maybe some extra flexibility in when to charge. Or double as a mobile power source on a school outing.

But if not that, it's just extra weight hauled around. And thus, decreasing efficiency. Not to mention cost / environmental footprint of an oversized battery.

It says in the article most routes are 80 miles on the high end but some are 100+ miles with one test on a 147 mile one way route.

Edit: and the transportation director doesn't like seeing you come home with an 'empty tank', plus buffer for running heat and a/c during an unplanned stoppage.

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