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Comment by javiramos | Hacker News Reader

Trucks seem to be the perfect candidate for electric propulsion. The high torque of electric motors just make sense for urban acceleration/deceleration. As a pedestrian, one of the things I hate the most is the the dense, black smoke from heavy trucks.

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Agreed, particularly in an urban setting. In NYC the streets are quite literally with small to medium trucks, which are all almost certainly in violation of noise and pollution requirements. A fleet-type electric medium duty truck with swappable batteries would be awesome and I think governments should be bending over backwards to incentivize them.

Do you mean small vans like this one [1]?

That's a significant electric delivery vehicle fleet, though from almost 10 years ago -- I don't know what happened since.

[1] http://www.j-sainsbury.co.uk/responsibility/case-studies/arc...

Oh that's cool, I'd never heard of it. I'm surprised there doesn't see much momentum in the area, although maybe there is a good practical reason for it.

Those are everywhere here nowadays. UPS, DHL, etc also almost exclusively use electric vehicles in and around Hamburg, which is really amazing.

You reminded me that electric home grocery deliveries have a longer history in the UK than people might think - growing up in the 1980s in the UK daily milk deliveries via an electric milkfloat were absolutely ubiquitous, and had been since the 1940s. The distinctive whining sound of a milk float pulling away, milk bottles chinking, was the definitive sound of a town waking up in the morning - diesel-motored vans chugging around first thing would have been incredibly annoying.

They are still used in the utility fleet space. However, they did not perform that well (range, reliability, high cost etc). It really was a natural fit for a Utility industry because of their access to the cheap electric power.

Unfortunately the range is becoming a problem on big electric trucks. The batteries cannot store as much energy per weight unit as the chemical fuel. This can be circumvented by using electric wiring overhead.

Sweden is prototyping an electric highway for trucks. It'll make transport cheaper and less damaging to the environment.

It's less of a problem in dense urban areas, where distances are short and there are many opportunities for regenerative braking.

>> Unfortunately the range is becoming a problem on big electric trucks.

Right, there's only a 126 mile maximum range on that truck. So you'd have to stop and get a new battery every 2 hours, minimum on the interstate.

The point of an urban transport truck is to transport goods within dense urban areas so that we don't have to suck down exhaust fumes all damn day. Your objection is absolutely irrelevant. You could have realized that by reading the entire title of the article!

An "urban transport truck" would do poorly on the interstate? How unexpected!

I'm just adding to the post I replied to, I realize it is an urban truck

> Unfortunately the range is becoming a problem on big electric trucks.

This specific effort is urban deliveries, 120 miles should be way more than enough.

> This can be circumvented by using electric wiring overhead.

You'd need much denser pantograph networks than any I know of for debatable benefits since the vehicles would still need the ability to go "off-network" (to enter private premises for instance). And for longer ranges, you might as well just use trains.

It's not as simple - with current charging speeds, 120 mile charge is not enough even if you're doing 10 mile deliveries; you need to figure out some solution that can keep that truck running for e.g. a 12 hour shift with limited downtime.

A gas tank with barely enough gas for 120 miles would work, but a battery for 120 miles can work only if you can quickly, easily and safely swap the batteries in your depot.

A fast (level 3) charger can recharge a 120 mile truck battery in 1-2hrs today and potentially less than an hour in the future.

A Tesla Model X (5000lbs/2500kg) pulling a 5000lbs trailer uses about 700Wh/mi. If you assume 1kWh/mi for a small delivery truck, you'll need a 120KWh battery.

ChaDeMo chargers are ~62.5KW, Tesla Superchargers are ~135KW and future level 3 chargers could go up to 300KW.

> 1-2hrs

So 12.5-25% of an 8hr shift. I would guess that would be unacceptably long for a large number of transport operators.

Aren't these mostly for domestic (or at least local) deliveries? I suspect they are currently delivering in only 1-2 8-hr shifts.

Trucks do not work 24 hour shifts, they sit parked while their drivers are clocked out. Truck drivers are limited to 11 hour shifts and must take a 30 minute break after the first 8 hours. So an electric truck that can be recharged in 30 minutes only needs to last for 8 hours to be a drop-in replacement for a diesel truck. And nobody said they have to be a drop-in replacement — it is entirely possible that savings on fuel will make up for whatever productivity is lost stopping to charge.

All that said, I don't think electric semis make much sense for long-haul trucking. That market would be much better served by electric trains. What does make sense is using smaller electric trucks and vans for local deliveries and waste pickup.

> only needs to last for 8 hours

I'm sure plenty of trucks drive more than 120 miles in 8hrs.

Trucks in general, sure. Urban delivery trucks, probably much less frequently, since they are traveling pretty slowly and making frequent stops. If you were driving around Manhattan non-stop for an entire 8 hour shift at the average speed for vehicles in Manhattan, you would only make it 68 miles.

I'm sure there are scenarios where the limited range would be ok, just as I'm sure there are those where it would be unacceptable. I don't know enough about supply logistics to say what percentage of trips taken by different size classes of trucks have a range that would fit the capability. I just wanted to suggest that overall the limited range also limits the value proposition of the vehicle, just like for electric passenger cars. Diesel semis get around 6 miles per gallon, versus around 30 for cars, this suggests to me that the trucking application is even more sensitive to limited ranges than passenger cars.

> That market would be much better served by electric trains

It would be, except for how difficult (right of way) and expensive it is to expand the rail network, and the extra work in moving between modes (since the last mile will be truck anyway).

Adding pantographs or inductive or something to for trucks to use on existing highways would be a lot cheaper and quicker to scale up than expanding rail.

How much range do they need for a 12-hour shift? Once you hit that you're good for most uses, since trucks usually sit idle overnight, plenty of time to recharge back to full.

Okay, actually for city deliveries with low speed limits and lots of stops plus traffic lights (regenerative braking instead of wasted gas while idling!) 120 miles is not as limiting.

I could realistically assume that you're driving only 2/3 of the time at average speed of 30 mph... and that comes out at just 240 miles per a full day, and you could get a partial charge during e.g. lunch break, so if the battery was just a bit larger, then it's actually feasible.

That sounds about right. My experience with a Tesla is that city driving is somewhat more efficient than highway driving, typically. The constant starts and stops still cost you, but not as much, and the lower speeds make up for that loss. I don't know how how true that would be of trucks, but I'd guess it would be similar.

With good DC charging, you should be able to count on adding 50% of your battery over a 30-minute lunch break, so if you do 240 miles in a day, your battery pack would need to be able to handle 160 city miles. Less if your truck is idle more or if it could charge more.

Looks like the average for delivery trucks is 13,116 miles per year[1], which is 65 miles a day if it only runs 200 days, or 44 miles per day if it runs 300 days per year (6 days a week minus a few holidays.)

1: http://www.afdc.energy.gov/data/10309

Oh wow, that's substantially less than I imagined. Thanks for the hard data!

You're welcome. I can't claim much credit for 15 seconds of Googling; it's very distressing how most discussions related to electric vehicles on HN are fact-free.

I know what you mean. Somehow it didn't even occur to me that this information would be available. I've been using the web for 20 years and I'm still not 100% used to having the world's information at my fingertips.

No kidding.

Particularly when major energy consumption patterns, and transport especially, have been studied to death. There's exceedingly good data out there.

Thanks from me as well for turning that up.

well I would think school buses and even metro transit buses would make better options. School buses because they travel fixed routes, have specific points they will sit awhile (schools/depots/etc) and the fuel price fluctuations clobber systems.

There are plenty of hybrid buses in Europe, in some cities the entire fleet, though only a few places are using full battery-electric ones. (Example in Gothenburg [1]). Even hybrid buses are a big improvement — the batteries can be used to accelerate away from stops, so you don't get exhaust in your face after alighting.

In Eastern Europe there are some trollybus systems, for example in Bratislava [2]. I like this -- no pollution in the city, and lighter vehicles with good acceleration and no rumbling engine.

[1] http://www.goteborgelectricity.se/en/node/19505/about-electr...

[2] https://en.wikipedia.org/wiki/Public_transport_in_Bratislava...

Trolleybuses exist in the US too in a couple of cities. SF and Seattle both really like them because they have all their torque available from a standstill, unlike ICE buses, so they are great on our absurd hills.

Seattle's new ones also have batteries so that they can run off-wire if they need to detour.

Trucks seem to be the perfect candidate for hybrid engines. Electric motors and batteries for the power needed to accelerate and climb hills, and gasoline for the energy density needed to actually get very far.

Trucks only need 200 hp to cruise so a 100 hp engine would extend the battery range a lot. I bet you could even take one of these 100 mile EV trucks, put a Prius engine in there, and make it go all day and double or triple the miles per gallon over a normal truck with 600+ hp engine.

Trucks usually need long range which isn't very good with electric since that adds weight. Weight is a huge issue with trucks as well since they have load limits (some countries factor in the truck not just the haul). As trucks burn fuel they also become lighter, the effect isn't as huge as airplanes but it's still there.

The effect is pretty much insignificant compared to airplanes or rockets. The fact that the fuel being burned makes the truck (slightly) lighter has a negligible effect on fuel economy.

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