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Comment by skystarman | Hacker News Reader

I worked in the commercial trucking EV space for a little bit and I don't know anyone in the commercial trucking industry that genuinely thinks batteries will be the solution for long-haul, class 7 & 8 trucks. At least not in the next decade or so, if ever. Elon and Tesla will tell you otherwise but there's a reason their Semi has been delayed for 3 years now...

Short haul, drayage, etc. is definitely workable with current tech.

They batteries you'd need for 6-700 mile daily drives would mean you're carrying a tiny fraction of what a ICE truck could haul due to weight constraints. We are making strides in this technology but are still nowhere close.

Almost everyone I've spoken to believes hydrogen is far more feasible, but it still has its own issues most importantly the massive infrastructure investment to support it.

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It's amusing to watch folks bend over backwards to propose workarounds for the hard thing that solves the problem: developing a sustainable, energy dense fuel.

We already have it, it’s called electrically synthesized methane/propane.

If the carbon is captured from the atmosphere and merged with water via renewable sources, that is it. We don’t do it and it isn’t proposed because the efficiency losses are crazy, and we aren’t in a world with over-abundant renewable energy widely available for pennies on the dollar (yet)

Yeah, with the addition that if you're going to go the synthetic hydrocarbon route you might as well go all the way to a fuel which is a liquid at normal operating temperatures to simplify logistics (and which isn't a massive GHG when it accidentally leaks like methane).

Advantage of shorter carbohydrates (like propane) is that they're made up of less carbon relative to the hydrogen (compared to longer chains), so for the same amount of energy stored, you need to capture less CO2 from the atmosphere or from wherever you're taking it.

Propane can relatively easily be compressed to be liquefied at room temperature. Takes just a few bars of pressure.

Let us quantify your statement!

By my calculation, you need to capture 0.9176 carbon atoms from the air to make propane whose energy content is the same as octane made from 1.0000 captured carbon atoms.

I used the "Std enthalpy of combustion (ΔcH⦵298)" of the 2 fuels from Wikipedia in my calculation.

... which of course requires hydrogen.

Biofuels are one way. Basically get algae to absorb CO2 and produce fuel.

Especially interesting because you can just mechanically press the oil out, which is very easy to turn into diesel. Unfortunately the cost/benefit doesn't seem to be there yet.

Lithium batteries have tripled in energy density since 2010 while the price has dropped about 90% I believe.

I was pretty skeptical when Tesla announced the Semi but the trend lines are there if not on Elons over promise timeline.

I agree it will be some time before they are viable for long haul, but a lot due to charging infrastructure.

Weight is the big question mark, I am anxious to see the Tesla semi battery weight and final capacity to see how viable it is. My guess is around 10,000lbs and a megawatt-hour capacity for 500 mile range. I imagine them trying to do a structural battery to try and make up for its weight. The equivalent diesel drivetrain is under 5000lbs including engine and can have up to 2000 miles range.

“Lithium batteries have tripled in energy density since 2010”

No they have not. My 2021 iPhone does not have triple the energy density of the 2010 iPhone.

The battery cells have improved but that is a packaging improvement, not battery improvement. Other companies are doing pouches for example. And then there is the question of cooling, do you include it in the weight calculations?

From what we know a Tesla model S in 2020 does not have triple the capacity of the model s of 2012. We only saw an increase from 85kwh to 100kwh in 2020. That is 20% increase not 300%.

https://cleantechnica.com/2020/02/19/bloombergnef-lithium-io...

Your iPhone example is problematic because Apple has so many competing requirements, but ok... Battery capacity from the iPhone 3gs to the 12 increased by over 2X. Sure, some of it is packaging (the 12 is 15% heavier) but the biggest factor is better chemistry.

Would you have been OK with GP saying 2X instead of 3X?

No, because newer iPhones are larger and have physically larger and heavier batteries that help them store more energy. iPhone 11 has a density of 250 wh/kg and the iPhone 4 was around 200 wh/kg.

That is again not even close to 300% increase

I am looking at apples documentation. Not sure where you folks are coming up with your imaginary numbers.

https://web.archive.org/web/20191007202842/https://www.apple....

You're comparing less than ten years. Here's what I see, 2009-2019:

iPhone 3g: 4.5 Wh / 0.0335 kg = 134 Wh/kg

iPhone 11: 11.91 Wh / 0.047 kg = 253 Wh/kg

For a 1.9X improvement.

Agreed, consumers aren't seeing 3X. But they should be seeing better than 20%.

Not sure where you found the data for 3g and whether they follow the same methodology as apple (the report shows up to iphone 4 which was introduced in 2010), but even if I assume that they are correct, what you are proposing is even more far-fetched.

That in 2010 something dramatic happened in the battery technology world and they doubled in density overnight. Hint: No they did not.

I'd be curious to get your take on what these guys are doing?

Apparently they have a cost effective way to upgrade existing diesel trucks with battery + LNG to extend the range.

https://www.hyliion.com/

The only way to make electric long haul trucking work out is overhead wires. Trolley buses in some cites do this, (the latest have enough batteries to run for ~5 miles without a wire which is useful for a lot of applications)

Or better yet the freight railroads need to figure out how to serve their customers better. They are already more efficient than existing trucks, and overhead wire locomotives are already on the market. The US has the best freight rail in the world - and they still lose a lot of potential customers because their operations are so customer unfriendly.

Wire trucks are tested in Germany and Sweden that I know off. I too think that it might actually be really viable to avoid tons of batteries - unless there is some technical issues I am unawere off.

An inductive system under the road surface would seem easier to install and would work better with different vehicle sizes. Suspending lines across a multi lane highway would need a lot of structures.

There is no way you could pass enough current via induction without setting things on fire or microwaving the occupant of the cab (or both). If it was viable, people would be pursuing it already.

Even if it was safe, the efficiency is much lower, and it is a lot more expensive. Wires overhead are much cheaper than than wires in pavement. It is more expensive to put the wires in pavement, and you need a lot more to get the induction to happen.

Not induction but conductive rails are already in use on test stretches of road a few places.

https://en.wikipedia.org/wiki/Electric_road

I cannot comment on efficiency and the like but today in Milan, Italy the first few new on-the-road public buses "fast" (200 kW) charging stations went into operation:

In Italian but with images and videos: https://medium.com/lineadiretta/installati-i-primi-charger-h...

This is the solution Volvo has proposed except with guard rails instead of overhead wires because they are incredibly brittle. Almost anything can tear it down in inclement weather. At first glance it seems impractical because there are so many roads, but 95% of the time freight trucks say on the main highways. So you only need to electrify those.

As an added bonus, it makes self-driving trucks much much easier to implement.

The hardest part is probably standardization. You'd need buy-in from the US, the EU and probably most of South-east Asia for it to be practical.

Eh, electric trains still use incompatible standards for different regions of the same country due to historical inertia. In comparison selling trucks with a different electrical pickup for each continent wouldn't be a big deal.

Overhead wires work fine with the railway network but somehow I think that having all these independently operated trucks drawing power on one pair of wires might be a challenging problem.

A single train draws a lot of power (several MWs) but it's one entity and as such can easily be managed in respect to having the power system functioning. But having tens, maybe hundreds of vehicles draw power on the same wires would need to be coordinated somehow.

I think a hybrid concept of electric trains for the long haul and electric trucks for the last miles might be promising. Possibly with autonomous freight hand over.

I think the efficient option is electrified roads you can drive over at 70+MPH. It’s simply the evolution of trolleys, but the chicken and egg problem is huge. ~15-50kw per car/semi takes a lot of power infrastructure. Still in road charging at say 20-30c/kWh could be extremely profitable and still much cheaper than gas. https://en.wikipedia.org/wiki/Electric_road

A huge upside is in road charging is nearly perfect for both load shedding and self driving cars.

I'm still going with batteries for the short haul trips, with trains for longer. There are too many roads to cost effectively electrify them all, that means there will always be short trips (my driveway at least) that need battereis. While we can electrify freeways rail is cheaper by far.

The point is electric cars with a 200 mile range and a significant electric road network simply makes internal combustion engines obsolete in a way that even a 500 mile EV doesn’t. Semi’s are a bonus at that point.

Anyway, electric rail is just down to the standard rail vs road brake down we already have. Roads are point to point without extra loading or unloading steps. Even with expensive gas and cheap electrified rail you still see a lot of long distance trucking. Long term with either electric highways or self driving trucks it’s going to favor roads even more let alone both.

It works out until you account for economics. It is cheaper to electrify a length of track vs a length of road. Rail also implies some form of planning to make the trip more efficient (rail works best with long trains - a situation that is unsafe on roads). Rail also allows a lot more cargo per lane/track and so it a lot cheaper - but only when you can take advantage of that. And so the real analysis is a lot more complex than could go into a 100 page report (much less a comment box).

Efficiency is always a function of usage. Electric rail lines have a much lower average demand for electricity. Here the efficiency of rail actually works in the opposite direction where battery power trains and electrified roads mean significantly less total battery needs.

Consider in terms of electric highway usage, a car every 100 feet isn’t that dense and get’s you to a steady state of ~20kw * 5280/100 = 1MW of power for several hours a day. Electric trains have higher peak demand vs cars, but it’s on a very infrequent basis.

Of course every car isn’t EV and right now ~0 cars can use in road power delivery. But, that’s just a chicken and egg problem not an issue with the technology.

> Short haul, drayage, etc. is definitely workable with current tech.

What's a rough estimate of the size of "short haul" vs "long haul" trucking segments?

long-haul trucks are capped at 80,000 pounds by regulation. do you happen to know what percentage of deliveries run at 100% weight or close to full capacity?

with further advancements, battery optimists expect the weight penalty compared to hydrogen at around 6,000 - 10,000 pounds.

by your estimate, how much of this weight penalty will translate into actual lost cargo -- and thus lost sales?

> with further advancements, battery optimists expect the weight penalty compared to hydrogen at around 6,000 - 10,000 pounds.

The penalty is unbounded because one has a higher energy/weight ratio than the other.

So with hydrogen at ~ 130 MJ/kg and batteries at ~1 MJ/kg, if you need a mega Joule then the weight difference is ~130Kg. If you need 100 MJ then the weight difference is 13000 kg, etc.

So each energy will have a different penalty. Let's look at trucks.

Today a semi will carry about 1000L of fuel (~260 gallons), which is ~40,000MJ. That would require ~300Kg of hydrogen (plus supporting weight for the container, etc) or ~40,000 kg of batteries (plus supporting weight for coolant, container, etc).

Thus what is economical for cars may not be economical for semis. There is not a single weight difference between cars and trucks.

Whereas a big jet can use 20,000 Liters of fuel which would require 800,000kg of battery + weight of supporting infrastructure or ~6100 kg of hydrogen.

So it makes sense that the two biggest truck manufacturers would be very interested in hydrogen.

There are other costs to weight other than cargo capacity, both for freight companies and society as a whole. More frequent maintenance, slower speeds, inaccessible and/or altered routes, more accidents, more wear on infrastructure.

I could reframe your statement like so:

~~ = strikethrough, italic = my inserts

"I worked in the commercial ~~trucking~~ EV space for a little bit and I don't know anyone in the commercial ~trucking~ industry that genuinely thinks batteries will be the solution for ~~long-haul, class 7 & 8 trucks~~ practical, affordable, long-range cars. At least not in the next decade or so, if ever. Elon and Tesla will tell you otherwise but there's a reason their ~~Semi~~ Model 3 has been delayed for 3 years now...

More often than not, innovation comes from industry outsiders. You can think whatever you want of Musk, but I think he has more than proven that he eventually gets the shit done he has talked about.

> practical, affordable, long-range cars

We don't have this in EV yet, or is it your perception that we do?

We do not. Most cheaper EVs are ~200 miles of EPA estimated range which here in the US limits the use of the vehicle significantly. You also have to account for the fact that EPA estimates tend to be fairly optimistic for the way some people drive.

A Model3 AWD (non LR) will struggle to hit 200 miles of range at 75+ MPH with the heat running and temperatures near freezing. For anyone in New England cold weather and prevailing highway speeds of 75+ are fairly standard.

> practical, affordable, long-range cars

I've been driving only EVs or PHEVs with big batteries for last 5 years. EVs are practical for my specific use cases. But it's a lie to say that we have EVs that practical, affordable, and long-range.

They're practical for people with garages. Affordable, only if you don't cross shop them same price point for hybrids, and don't compare what you get for the money. And none of them is long-range - ok range, at best. And not a single car comes close to being both affordable and long-range.

Emphasis on the "don't compare what you get for the money". The Tesla Model3 is nice, but once you get close to $50k here in the US you're up against much much nicer vehicles to spend a few hours in.

I bought a car 2 years back and test drove the Model3 as one of the contenders. The two things that led me to skip an electric car this go around was the poor dealership support that I had a couple of owners warn me about and the fact that the Model3 interior is pretty awful compared to what you get in most entry level Japanese and German 'luxury' cars. I'm a car guy, I can't justify spending that kind of money on something I don't absolutely love.

I'm excited to revisit the decision a couple of years down the line.

Unless you look at Japanese or German cars I think you'll be disappointed. It's not that Tesla has poorer interior than other American cars. In general they all have plastic-y, toy-like interior. Even cars more expensive than Tesla have this problem. And then there's the interior design. Cars half the price have much higher interior quality in German and Japanese cars (and Korean and French and Chinese and...). It has always been like this for some rreason. Have you seen a Mustangs interior? Yikes!

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