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Comment by mrmckizzle | Hacker News Reader

I'm surprised, I thought the electric engines would supply more torque. Thereby making it easier to plow snow.

It's not a good headline, if you read the article it is mentioned that the tested vehicles could only operate for 4 hours before "conking out". Which I can only assume means they are running out of charge. I would expect the charging time for these niche vehicles is not state-of-the-art and the infrastructure is poor, so that makes sense.

Thanks, I should of read it more thoroughly. Skimmed it instead, did a second pass and noticed a paragraph regarding vehicle charge longevity and the lack of charging stations.

While the headline references "power," the issue is that these electric trucks do not have enough battery capacity to plow snow for a full day before recharging overnight.

I have always thought that municipal road services had great potential to be electrified via partial catenary: take power from (and charge batteries) where the roads are electrified, discharge battery where the roads are not electrified.

Stupid question so, why would you use a garbage truck to plow snow? Over here, cities, towns and musipalities use different vehicles for different jobs, suxh as garbage, snow plowing, street cleaning and so on...

> why would you use a garbage truck to plow snow?

They're optimizing for trained drivers who can drive safely in the snow rather than hire two.

For a dangerous job on snowy roads, I think the fewer people employed with better pay is better than more people with lower pay for the same skills.

That said, there are a lot of places which can buy EV garbage trucks before we get to the snow or ice.

Who's not buying them is not as relevant when we're supply capped on the production of decent trucks with batteries in them.

Sure, it affects the total-market calculations & how the development is funded, but might not change how many are sold per-year until the production scales.

This is a guess but most cities have a road/right of way department that does snow removal. For whatever reason, in NYC this is apparently done by the sanitation department. I think this is a meatspace Conway's Law, unrelated to whether or not it is actually better to have separate trucks or not.

It is one of those solutions that at first look might sound good. But with closer inspection there is more and more problems. Like for example is equipping the trucks sensible? And what happens to the garbage that should have been collected? And training people for both jobs. As driving snow truck does require some expertise.

This is one of those objections that sounds good at first. But upon closer inspection you find out that the practice of using one truck for two different sorts of jobs has been commonplace for decades and it works out fine.

Garbage trucks have easy attachment of snow plows and allow existing infrastructure to be on double duty. In a place like NYC storage of this many vehicles is also a concern, so just doubling your fleet for winter (3, maybe 4 months) usage isn't ideal either.

They very rarely need to plow snow in New York city, but when they do there are hundreds of miles to plow, and it is much faster if they begin the plowing before even an inch accumulates.

It is much more efficient to press the thousands garbage trucks into this rapid snow plowing service a few days per year than to waste 20 acres storing snow plows for the 350 days per year when they are not needed.

They also bury the trash bags under the plowed snow, which is a win-win for them because they can forget about collecting them until spring. :)

This and also: NYC residential trash collection is curbside. Literally leave trash bags on the curb. Trash collection cannot occur when the curb is snowed in.

So, were there separate trucks for the two tasks, the trash trucks would sit idle until after the snow plow trucks had finished their rounds.

Given the infrequency and relatively small volume of snow NYC gets, plus the curbside trash collection, sharing trucks and drivers is reasonably efficient.

NYC does have a number of dedicated salt-spreader/plow trucks [1].

As for why they use garbage trucks to plow, I speculate that it's an issue of scale. Buying a special purpose plow truck to replace every garbage truck that currently does double duty would leave you with a pretty significant/expensive fleet of trucks that are sitting idle most of the time (not to mention taking up space, which is at a premium in NYC).

[1] https://www1.nyc.gov/assets/dsny/site/about/fleet

It's not a torque issue. from the article: "We found that they could not plow the snow effectively – they basically conked out after four hours. We need them to go 12 hours,"

The author of the article doesn't know what they're talking about. The issue in question is concerned with energy density, not break power of the motors. Electric motors are capable of delivering far greater torque than a similarly sized (weight/volume) diesel engine. Electric batteries on the other hand have far less energy desnity compared to an equivalent volume/mass of diesel fuel.

It’s brake, not break. As in the amount of HP available at the brakes after all transmission/diff/etc losses are taken into account which doesn’t even really apply to electric vehicles.

They aren’t looking hard at all. If you just had a super capacitor bank to capture regen, all the energy from the stop and go could be retained and they could probably run the truck on the batteries that they are currently saying last only 4 hours.

Brake horsepower is the power at the output of the engine. It's called that because it is measured with a brake dynamometer. Wheel horsepower or wheel brake horsepower (same thing) is measured after mechanical losses (at the wheels).

But "they aren't looking, why don't they just.." really rubs me the wrong way. Surely these people are experts in their own field and know what's available. After all, they are ordering trucks from a vendor, not designing trucks to their own unique requirements. Plus these Mack trucks indeed already have regenerative braking.

Ha, yup, I used the wrong "brake". Silly me. The point is that power delivery and energy capacity of an energy conversion system are two different things and the author's incorrect usage of power to refer to energy is pretty egregious and is spreading an idea that is false - that electric motor vehicles deliver less power than combustion engine vehicles. That's my issue.

One only need look at the volumetric and mass energy density of diesel fuel and electric energy storage options to see that electric vehicles CURRENTLY store significantly less than diesel fuel tanks. That's well known and not a shock to anyone. Energy desnity of electric power storage (batteries, or even H2 fuel cells) will improve over time.

From the article, it doesn't seem to be about torque. Their issues are charge duration in the battery (in cold conditions it only lasting 4 vs 12 hours) and the fact that they have to use garbage trucks at all compared to other municipalities using smaller trucks or dump trucks/graders. Apparently the city has committed to using the garbage trucks.

Pushing snow is hard work. Harder than towing a large payload, so it makes sense to me that electric garbage trucks that might last a full day of garbage collection will fail to last as long while pushing around tons of snow. Just a simple matter of physics here.

Peak torque isn't the issue. It's how long the batteries can sustain sufficient torque

Cold weather and battery life are two things that do not get along.

That, and when it snows in NYC, we tend lose power, so I don't know what the contingency is there. Diesel generators, I suppose. Is that better?

If only they could throw some kind of diesel generator in a truck. You could plow a ton of snow

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