[limitedfrom]

> “They have more energy in each bus than they need to do their route, so there’s always an ample amount left over,” said Rudi Halbright, product manager of V2G integration at Pacific Gas and Electric Company, the utility that’s partnered with Zum and Oakland Unified for the new system.

This just sounds like the batteries are oversized for the application and they're carrying unnecessary weight around all day. Consumer EVs are doing this to an insane degree all day for "range anxiety", but I can't help but think that well defined space like school buses could be sized much closer to the true requirements.

[Gigachad]

The buses will all have different length routes, you aren’t going to custom build a bus for a single route and then have it be impossible to reassign later. The batteries will also degrade over time so you wouldn’t want them left completely useless when they degrade 1% and can now no longer complete the route.

[limitedfrom]

To some extent, definitely. But I'd like to think that

1) School districts could buy a mixture of different ranged buses to fit their needs. After all, airlines have a mixture of planes in the fleet for different range / needs and not just have all the fleet be the largest / longest range model, and

2) The manufacturer offers range conversions later since it's a more commercial use than consumer EVs, especially when they want to sell it to different school districts. They probably need to do battery swaps when batteries degrade beyond a certain degree anyway.

Carrying additional capacity takes a lot of material (that could be used for other batteries especially) and energy. I get that it's convenient, but I hope folks put a little care into it than just put large batteries everywhere.

[dgoldstein0]

Not necessarily. The battery may be able to provide power to the grid when it's low and does not enough power to drive the bus. The bus probably requires some minimum voltage to move and a bit more to be able to climb hills. And of course you don't want to run out of power so more buffer for that. So it's not unimaginable a bus could be near empty for the purposes of driving the route but have useful juice to give the grid. Fair question would be how such discharging affects battery lifespan

[dangus]

I disagree with you here.

It’s not just range anxiety. You need to have extra capacity for cold weather and degradation over time.

If I have a car with a 300 mile range, and it’s 0 degrees outside, now I’ve lost a solid chunk of range, I’m down to the low 200’s

Then, if the car is 15 years old, I’ve lost another 10-20% of battery capacity.

But I also need to stay below 80% charge or I’ll double my charge time, so really I only want to operate between 5-80% on a road trip.

Now I have to charge every two hours of driving or maybe even less.

Compound that more if I need to tow something, put a kayak on the roof, put a bike on the back, etc.

So if I’m starting from an EV that has a more reasonably sized battery pack delivering 150 miles of range, well, maybe I can tolerate that but not in the winter 10-15 years from now.

Of course this discussion isn’t extremely relevant to school buses.