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Comment by legohead | Hacker News Reader

If you are curious about the fuel like me -- 10% of the new vehicles will be electric [1].

[1] https://www.theverge.com/2021/2/25/22300281/usps-new-mail-tr...

Awesome that it is designed to be electric conversion-friendly. I'd call this a win for functional design constraints because it looks very practical, in a good way. Needs: safety and efficiency.

Too bad it’s not higher. But that’s a good start. It’s a clear win for a well-engineered electric drivetrain given the low miles typically traveled per day (BUT high total miles on odometers as they’re made to last decades), typically low speeds, and extensive stop and start. Playing almost entirely to electric’s strengths and the weaknesses of internal combustion. In an ideal world, I’d hope it’d be 50% electric and 50% plug-in hybrid.

I can't imagine more than a handful of post offices are ready to plug in all of their trucks right now. They're almost all going to need power upgrades.

Electric delivery vehicles could easily be charged overnight from regular 'residential' outlet.

Since average mail route is 45miles [1]. At 1000Wh/mile - that's only 45kWh of charge needed per vehicle.

[1]https://www.grit.com/community/usps-rural-delivery-factoids

Probably more like 300Wh/mile. A Tesla Model 3 gets 4miles per kWh and that’s measured at higher average speed. At 3.3miles per kWh and 1.3kW for a typical L1 charger (literally just any standard 120V outlet), the average 45 mile range (13.5kW) would be charged in just 10 hours. With probably 14-16 hours charging each night, that's plenty to replenish greater than average usage as well. Put a 300 mile range battery in there, and you only need to charge once a week. (And note that the old Grumman LLV only had like 13.3 gallons and atrocious 10mpg, so that'd be like double the range and less frequent fuelings/chargings.)

"A Tesla Model 3 gets 4miles per kWh"

At cruising speed, I assume? Delivery is going to be radically worse, because it has a ton of start and stop operation, the worst case for consumption.

You also seem to be spec'ing what it looks like for a post office to recharge one vehicle. What about dozens, plural? A current post office needs only marginally greater power than a residence. Charging dozens of electric vehicles is going to need more than that.

10 vehicles, charged for 8 hours would draw 234Amps of current. About as much as single residential drop. Some houses even have 400Amp panels.

Given that USPS fleet would be upgraded over number of years - power delivery is really not a problem.

Roll down to your post office during off hours and count the number of trucks. I live in a very small city (people used to SF or NY wouldn't even call it a "city") and we've got dozens.

Not sure where you're getting the 1000Wh/mile number, but if it's from "normal driving" it won't apply. Mail delivery is stop and start, which is much worse. (If regenerative braking was 100% it'd be fine, but it's nowhere near that.)

Model 3 in Winter with heating on uses 420Wh/mile when driving 70mph. I think 1000Wh/mile is very generous estimate.

I think you are all greatly underestimating how much damage it does to drive down a neighborhood, stopping every hundred feet, and re-accelerating. Cruising speed consumption is not a useful number here.

Well, that should be part of the plan too. We're making ourselves poorer half-assing everything.

Things take time in the real world. Unfortunately there are whole supply chains to deal with. 10% is a solid start and shows intention beyond just a proof of concept.

That sounds like an excuse. They’re already using vehicles today. There’s no good reason that 90% of these can’t be electric.

There are probably a lot of reasons. You are assuming there is no good reason, but obviously there is.

Literally just need a 120V outlet.

You can’t tell me that exterior outlets are rare or expensive. The fuel saved in a single year would easily exceed the price of putting some exterior outlets in a parking lot.

Maybe not, but it's possible many post offices would need electrical supply upgrades to handle having their entire fleet plugged in all at once. Not impossible or even difficult, but not free either.

I would assume they're already in half the parking lots in the North - block heaters would require outlets, so anywhere that gets below -20C would likely be able to have electric vehicles today.

Block heaters are only needed for diesel vehicles or areas with really low temperatures. I live in Michigan and the only block heaters I know of are used for school buses.

I guess I'm wrong. I assumed they'd be more common, given how everyone I know has one in southern Alberta (Canada). I thought America would be similar in areas to the North. Granted, -40 (which it gets to here) does count as really low.

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