For grid bases storage, energy density does not really matter. What matters is cost and longevity. There are a few emerging battery chemistries that promise to be cheaper and more durable than lithium ion and less vulnerable to hot/cold temperatures as well. The energy density for these is not good enough for things like cars or trucks. But that doesn't matter if the primary application is setting up stationary storage in some field in the middle of nowhere. You literally can just plonk down some containers and wire them up. What matters is being able to deploy these things quickly and cheaply and not having to expend a lot of energy on heating/cooling or worrying about these things catching fire.
For cars and trucks, current batteries are actually fine. Higher energy densities are mainly nice for things like high end sports cars where the form factor prevents cramming in more battery. But less so in freight trucks. Saving a few hundred kilos of mass on a truck that pulls 80 tonne is just not that valuable. It's nice but only if it doesn't raise the price too much. So what if you need a two tonne battery? The main constraint here is cost, not weight.
The aviation market on the other hand has an insatiable demand for high energy density storage. Hence companies like CATL announcing 500wh/kg batteries recently. That's double what you'd find in a high end car these days. And apparently they are working on even higher energy density batteries already.
Probably these are really expensive and hard to get. But it's going to add quite a bit of range to things like VTOL planes, drones, and other flying things that run on batteries. So, a NASA battery with high energy density and a few other nice properties (like needing no cooling/heating) could be worth the extra cost in this market. And better longevity means more time in between expensive overhauls as well.
> Saving a few hundred kilos of mass on a truck that pulls 80 tonne is just not that valuable.
From my understanding of the trucking industry, in many sectors, this isn't true at all. For example, in tipper trucks where you are carrying literal dirt and rocks from one place to another every kg counts and tare weight of the truck is very much a consideration, even in the relatively minor variations between diesel trucks.
In the US weight restrictions are even lower than in Europe in many states.
> In the US weight restrictions are even lower than in Europe in many states.
Given that road wear grows to the fourth power (!) with vehicle weight, I hope you guys feel well with the fact that your tax dollar subsidizes those ultra heavy trucks.
Seems reasonable given, you know, they are also delivering our food, fuel and basically anything else you need or want. They also pay a considerable amount of road tax and taxes on fuel which would make most people in the US plot a coup.
Trains have never delivered to individual retail stores, half finished housing estates or petrol stations. Perhaps reserve your sarcasm for when you aren't saying something stupid.
I'm not even sure what you are trying to say. Perhaps try having a grown up discussion rather than trying to win internet points via your superior sarcastic smack downs.
Retail stores certainly existed before the automobile. People walked, biked or used horses to get to them. Horse and cart were used to deliver things to them.
This is not totally true. It was very common to have markets right next or even under train stations. It was also common for trains to do milk delivery with stores close to rail stations. You also had trains going threw cities on street levels to unload.
But this isn't really the right debate. Sure you need some last mile in many cases, but that's also often true with large trucks.
The simple fact is a far, far, far larger amount of transport could be handled by train if society put the right insensitive in place, rather then the completely backwards intensives that exist now.
In Switzerland its quite common for example to have even fresh food transported by train, the largest retailer works closely with the rail company and delivers to a number of regional depots where smaller (sometimes small or medium) trucks then take it to individual stores. We don't have these Wallmarkt supper stores that Americans (unfortunately for them prefer).
Its very common that larger stores, like Ikea actually are directly connected by the train network.
There could actually also be a lot more done to do cargo delivery by tram. This has started in a number of European cities. In Zürich the Cargo tram is currently mostly used for extraction of waste (like e-waste), not yet delivery, but it has potential.
Yes, by writing it by axle on the regulation is common. There is also a requirement for a minimum number of operating tires in an axle. (I don't keep close track of this, but I don't think it's always 2.) And requirements for tire pressure (that changes how much damage the truck causes too).
On practice the impact of the truck is determined by law independently of the weight (on those superficial models, but there is also some depth where the regulation starts to fail).
Where can we find more on this? I'm not doubting, but I can't think of why this is. It's pretty rare to find much in the physical world that uses the 4th power (Hagen–Poiseuille equation relating fluid pressure differential in a pipe - or artery - is one of the few that comes to mind)
I don't remember where but this is pretty common knowlage in urban design and transport engineering. Any textbook on road engineering should have that stuff.
From what I could find, the road damage 4th power relationship is empirically derived (in contrast to something like Hagen–Poiseuille) and the relationship is disputed by experts.
There already are battery electric trucks capable of carrying hundreds of tonnes of rocks. Australia actually has road trains north of 200 tonnes that are battery electric. The battery weight is mostly not an issue.
Weight savings are nice of course. But so is not burning diesel by the hundreds of gallons. The trade off is between a few percent extra weight or lots of dollars spent on fuel.
Current electric semis are only good for hauling potato chips (i.e. mostly air) for any distance over 100km.
Weight is very very valuable on both passenger cars and commercial trucks. Hauling those extra 300-500kg vs a comparable size sedan comes at a steep cost too, as increasing weight requires stronger/wheels body, wheels, brakes, even engines.
There is a huge demand for higher energy density, preferably of a non-explosive kind.
The blog in your link seems to conclude that electric cars pollute less than petrol cars overall.
Still, if the blog is true, it's still surprising that such a large amount of air pollution comes from tyres and brakes. A little Googling does support this claim.
It could have something to do with the fact that in order to regen-brake a 1800kg car at your typical 0.5g at 100 km/h you need some 270kW of motor/generator power. This is the main reason your Teslas and Polestars have these otherwise outlandish engines, and if you already have it, why not accelerate at traction limit, creating all these aerosols and what not.
It is extremely atypical to be braking at 0.5g. That is an emergency braking situation, in which case, it is perfectly reasonable to be engaging the mechanical braking.
I wasn't making any kind of comparison to petrol cars! I guess it seemed like I was and that explains the downvotes, perhaps?
All I was trying to do is add some support to the claim that battery density does matter in cars (contrary to ancestor assertion). Less weight = less strain on brakes and tires = less nasties in the air and our lungs.
Tyres, absolutely. Equivalent size EVs are heavier (due to the batteries) which creates more tyre wear. My brakes, however, wear far less than on a petrol car due to regenerative braking.
Brakepads are not an issue on EVs. They barely use frictional brakes.
My car is at 150000 miles and it's still on the original set of brakepads. Some EVs actually have a problem with that, their brakes are used so infrequently that rotors start to rust. So automakers added firmware that periodically applies frictional brakes.
Nonsense. There are battery electric trucks in every vehicle class you can name. 200 tonne road trains in Australia, check. Mining trucks, check. Not a problem. There are also multiple electrical class 8 semi's on the road already. Tesla class 8 semis is a good example. But you can also get similar trucks from e.g. Volvo. Long distances buses, school buses, vans, etc. All available right now.
As cost of the batteries comes down, these things will only become more popular.
Your article specifically mentions it's unknown what load they carried and the data suggests not a lot.
News from 2022 say they hauled chips for 400 odd miles, and limited soft drink sorties to about 100 miles.
EVs do 100% need to get lighter. They are still quite a bit heavier than their ICE equivalents and tyre wear is (IMO) underappreciated as a toxin/pollutant.
There are quite a few lighter EVs. Including some classic car conversions that actually manage to be faster and lighter than their originals. Those cute little EVs that are mass produced in China are far lighter than the super sized trucks people in the US drive. And of course any muscle car burns out its tires, brakes, and has terrible fuel economy.
You definitely don't need a 3t truck to carry your family, especially when you know how small modern families are… The average household size in the US is 2.53. And 63% of households are only made of one or two person (that is, the majority actually doesn't “have a family”), which fits in 482 kg Citroën Ami.
Also the most common car in Europe (Dacia Sandero), which is a 5-seater only weights 1 036kg. Gigantic American cars are a cultural phenomenon (which is mostly ad-driven by the way), it doesn't relate to an actual need.
I’m not discounting the cultural part because it’s a big factor, but you’re also missing that the US has more stringent safety standards that significantly drive up weight. There’s more reasons that those little Opals and Citroëns aren’t sold in the US beyond cultural norms.
> but you’re also missing that the US has more stringent safety standards that significantly drive up weight.
Source for that? From this 2015 study[1], it doesn't seems to be the case at all in practice. (And maybe it the safety regulation has tightened up in the US since 2015, but the car size difference had already existed for at least the past 2 decades at this point). In any case, given the car fatality rate in the US compared to the EU[2], these regulation seem pretty ineffective (no amount of car safety can compensate for the very low driving skill in the US, caused by very lenient driving license requirements compared to European ones).
Also, I don't know how US safety rules apply but that would be pretty stupid if cars capped to 50km/h were subject to the same requirements as highway-ready cars.
I used to work in automotive assembly as a robotics engineer. Besides being well-known in the automotive industry, it doesn't take a lot of internet sleuthing to find.
"In general, there are two reasons why late-model cars are much heavier than their predecessors: safety and convenience."[1]
"The U.S. has a bunch of extra safety standards that the Europeans don't. For instance, in America, car makers have to design airbags to protect people who are not wearing their seatbelt. In Europe, they just assume that everyone's buckled up."[2]
I think you're conflating standards and the result of those standards with your links. You can levy a bunch of requirements that drive up weight and also don't have a meaningful impact on safety. We might even agree that they requirements aren't particularly effective, but that doesn't mean the manufacturers can skirt them. Whether or not the standards work, the result is the same: heavier vehicles.
>I don't know how US safety rules apply but that would be pretty stupid if cars capped to 50km/h were subject to the same requirements as highway-ready cars.
The market for those vehicles in the U.S. is extremely niche, generally relegated to ATVs. So much of the U.S. is connected by highways that there's very few people who a) want/need to own a car and b) also have no need to travel on the highways. People who only want a small urban commuter will often just get a scooter or motorcycle.
> "The U.S. has a bunch of extra safety standards that the Europeans don't. For instance, in America, car makers have to design airbags to protect people who are not wearing their seatbelt. In Europe, they just assume that everyone's buckled up."[2]
Even if it's not mandatory, basically all cars have airbags in Europe nowadays, including tiny cars.
Come on: “By law, modern vehicles are required to be fitted with a variety of safety-oriented technology (anti-lock brakes, stability control and tire-pressure-monitoring systems, etc.) and equipment (air bags,laminated glass, door intrusion beams, etc.)” not only these things are also mandatory in Europe, all the given examples aren't even heavy to begin with!
> The market for those vehicles in the U.S. is extremely niche, generally relegated to ATVs. So much of the U.S. is connected by highways that there's very few people who a) want/need to own a car and b) also have no need to travel on the highways. People who only want a small urban commuter will often just get a scooter or motorcycle.
Yet American only commute 20 miles per day on average (at an average 30mph). The fact that highways in cities are “technically highways” is only a cultural (and political) decision: the same kinds of roads in Europe are in fact not highways and speed is often limited to 70km/h for instance in France.
Anyway there are highway-ready cars (with airbags, ABS and all) that weight less than 900kg in Europe (Renault Twingo, Fiat 500, etc.).
No offense, but I get the impression you’re speaking from a place of ignorance which makes it easy to latch onto pieces that confirm a preconceived bias.
Even if the cars all have airbags, it doesn’t mean they can pass US crash tests. That means they can’t nearly even be offered in the US. For example, EU frontal crash tests use a deformable barrier while the US does not. Relating to the study received for your safety assessment, it says the distribution of differences overlaps with zero. That’s a red flag that you can’t make a claim that they are any didn’t different.
Your claim about US commits is incorrect and less than half of the actual value in both distance and speed. Avg. speed is also not an appropriate metric.
I could go on, but there’s a lot to unpack. The latter point is that I’m not convinced you actually understand the differences between US or EU car manufacturing or parts of US culture that drive some of those decisions. There’s certainly an overrepresentation of SUV and trucks as commuter vehicles but there’s also a huge portion of the population, especially in the vast rural population, who have legitimate and pragmatic reasons to these vehicles. (And that’s coming from someone who drives a small hatchback)
> No offense, but I get the impression you’re speaking from a place of ignorance
Bruh, if you're gonna make statements like this, your argument needs to be stellar to back it up. And then you go:
> especially in the vast rural population
The US rural population is tiny, it's less than 20%, it's the same kind of argument as “people have families” when barely any household is more than 4 people.
The reason why almost 70% of people are driving an SUV or a truck has nothing to to with families (90% of which fit in a four-sitter) or the needs of rural life (that's also why pickup truck's bed has shrank so much over the past 5 decades). In fact, the growth in usage of these cars happened coincidentally to the decline of rural population and large families.
Your focus on safety as the root cause is also pretty dumb, since any SUV from the 90s would fail European current safety tests anyway, despite being enormous already.
> Your claim about US commits is incorrect and less than half of the actual value in both distance and speed.
Please provide your sources, because it doesn't match with what I could find online. (I realize that I made a calculation mistake: it's 20 miles and an hour in average so 20mph).
> Avg. speed is also not an appropriate metric.
Yes it is indeed. It's not perfect, but it's still appropriate, because it means that the commute time is driven by traffic congestion, and even your car going up to max speed for a small part of your trip isn't going to save you much time.
>Bruh, if you're gonna make statements like this, your argument needs to be stellar to back it up.
Well, for starters, did you actually look into the studies you cited or did you just take the first parts that confirmed your bias? For instance, the study that claimed European cars are safer in front/side crash tests admitted that the distribution of safety differences contains zero. It's important to understand the limitations of null-hypothesis testing. This means you can't discount that there is no actual difference between safety. This is why data literacy is important rather than just reading the abstract or conclusion and running with it.
>The US rural population is tiny, it's less than 20%
Again, this belies ignorance. Did you just grab the first Google result that confirmed your stance, or did you actually take time to understand the nuance? There is a massive disparity between what the census defines as rural vs. what is colloquially understood as rural. The census considers any population over 2500 people as an "urban cluster". That means US urban areas range from 2500-19.5MM. With that level of variance, you have to acknowledge large variance of “normal” use cases.
>Your focus on safety as the root cause is also pretty dumb
Please point to where I said it's the "root cause." I've only been advocating a more nuanced perspective. Also, see the HN guidelines for appropriate comments.
>Please provide your sources
The average round-trip commute as 55.2 minutes according to the US census and over 40 miles. Maybe you misspoke when you said "20 miles per day" and meant one-way?
>Yes it is indeed.
No, it's misguided and lacking nuance at best. Have you ever driven in southern California during rush hour? Your average speed is easily 30mph or less because you are essentially in a parking lot for huge periods. But that doesn't negate the need for a car to be able to reach highway speeds. Remember, the context was about safety of cars that are capped at 50km/hr, but now you're moving the goalposts and acknowledging the need for faster speeds just to maintain your position.
It's pretty clear you have your mind made up and prefer to argue rather than have a substantive and nuanced conversation.
> Also, see the HN guidelines for appropriate comments.
Coming from the author of “you’re speaking from a place of ignorance” (+ other variations), I can only hope you're trolling at this point.
> This means you can't discount that there is no actual difference between safety. This is why data literacy is important rather than just reading the abstract or conclusion and running with it.
Given that the argument being refuted was “US cars are safer” the “no actual difference” case still counts as a refutation. How good is data literacy if you lack logical reasoning abilities…
> The census considers any population over 2500 people as an "urban cluster"
In an area were more than 2500 people live you'll most likely have actual roads and bridges, and don't need a truck to cross rivers or to drive on unpaved roads, so the definition is pretty much on point when we're talking about cars! And then 71% of the US population live in urban areas of more than 50k inhabitants so the smallest urban areas are in fact a small fraction of the total urban population (Edit: In any case, urban population living in areas with less than 10k is just 7M[1] so it's not these 2% of the US pop who make the car market either…).
But yeah, I'm the one suffering from confirmation bias…
> Please point to where I said it's the "root cause."
> But that doesn't negate the need for a car to be able to reach highway speeds.
Sure, one car able to go to highway speed for vacations and all. But must households don't need two of such cars!
> Remember, the context was about safety of cars that are capped at 50km/hr, but now you're moving the goalposts and acknowledging the need for faster speeds just to maintain your position.
Saying someone is ignorant is not saying someone is dumb. Ignorance can be remedied with information, being dumb cannot. One is meant as a personal indictment of intelligence, the other is just saying you may not have the right perspective. If you took personal slight from the phrasing, it wasn’t intended.
There is no root cause claim there so you’re not saying much, other than strawmanning. If you look at a modern economy car, it weighs more than economy cars of the past or non-approved models for the US, despite using lighter weight materials for comparable components. So where does the extra weight come from? Mandatory safety features and options. That’s all the “disproportionate” statement is saying. It also wasn’t a comment to you, so a bit cringey that you try to search for any weak handhold to make your point.
You also picked a different comment to illustrate the context rather than your actual post, so I’m not sure your point. But it certainly lends credence to the idea of you moving the goalposts just to avoid being wrong.
I’ll give you more perspective since you missed the point. If the data contains zero it means it ranges from saying the US cars are safer to saying they are less safe. Zero is contained because it’s within this range. In other words, you can’t make strong claims at all. Again, data literacy is important.
Saying a comment is dumb isn't saying you are dumb. If you took personal slight from the phrasing, it wasn’t intended… not. And you know this argument is BS, you infringed the rules about civil discourse first, but now you're trying to use them so you gotta try something ¯\_(ツ)_/¯.
> If you look at a modern economy car, it weighs more than economy cars of the past or non-approved models for the US, despite using lighter weight materials for comparable components. So where does the extra weight come from?
Ah yes, because your old car also had AC, electric window, and all the comfort a modern car has (including the car's form factor, giving more room for arms and legs, and less effort to get out of the car), and then the only difference must be safety…
> You also picked a different comment to illustrate the context rather than your actual post
Yes I took an adjacent comment in the same thread that you posted 5 minutes before your response to mine. So that must count as a completely different context, right? No, and you know it as well.
> If the data contains zero it means it ranges from saying the US cars are safer to saying they are less safe. Zero is contained because it’s within this range. In other words, you can’t make strong claims at all.
Of course you can make strong claims, and you're even making a strong claim yourself right now! The claim I make (which is ironically the same as the one you're making right now) is that the study shows that you can't make a strong claim about the US safety being higher than the one in the EU. Which was your argument!
>Those cute little EVs that are mass produced in China are far lighter than the super sized trucks people in the US drive.
I know there are steep tariffs on Chinese EVs but I’m also wondering if these “cute little EVs” would pass US road safety tests. A disproportionate amount of weight in modern cars is safety equipment.
> Higher energy densities are mainly nice for things like high end sports cars where the form factor prevents cramming in more battery. But less so in freight trucks. Saving a few hundred kilos of mass on a truck that pulls 80 tonne is just not that valuable.
Disagree. Car and truck makers try to optimize for grams and saving a kg of production vehicle is considered a huge engineering victory. Saving 100s of kg is a gigantic deal.
This is true. Just look at Fords decision to go with an aluminum bed on their F150. Going with a material that is more expensive and less durable on their best selling vehicle that’s also a work truck is a big deal, but worth it given the weight savings.
CATL's sodium ion batteries are slated to soon (1-2 years, mostly just mundane factory construction and logistics) to hit $40/kwhr. No nickel / cobalt / etc.
I think LFP is basically already under that as well (I think they are in the 60-70/kwhr range).
For grid storage, that is probably the only metric that matters: cost per kwhr of storage (and sufficient cycle endurance).
> the battery catalyst is a Nickel-Molybdenum-Cobalt alloy, which seems like a pretty rare, expensive component.
So you didn't read the article? The piece states: "Yi Cui’s team found an inexpensive nickel-molybdenum-cobalt alloy catalyst for the battery that costs $20/kg." For a catalyst, that doesn't sound too expensive.
> Their published research cites a $~83/kWh cost for just the materials (that's not very cheap)
That's all very nice, but that number is from a paper from 2018. And they state that it is the battery cost: "The estimated cost of the nickel-hydrogen battery reaches as low as ∼$83 per kilowatt-hour".
Part of my critique is that the numbers cited in the article don't relate to their meaning. Measuring catalyst by kg instead of kWh is stupid, so $20/kg means jack when you look at what that actually means for a battery. Sounds hard to believe that there is an inexpensive anything made of only things like nickel-molybdenum-cobalt.
> That's all very nice, but that number is from a paper from 2018.
Hey I agree with you, but that's what the article cited. Maybe they shouldn't be citing a 2018 article. And I bet that $83/kWh was absolutely a best case estimate without manufacturing costs, nor accounting for scaling costs. Thats why I added the link for context.
Regarding affordability, if this battery can achieve 30,000 recharge cycles vs 500 for li-ion, then relatively small differences in materials cost will be irrelevant, no? Particularly if used for grid storage.
This sounds great on paper but there’s a couple of questions left hanging:
> We take the battery, put it in an open fire, and watch it continue to heat up. What ends up happening is that the pressure above top charge will force the hydrogen back into water. And then we have a release valve designed into the unit so at a predesigned pressure and temperature that will release, and you’ll get a steam vent.”
But what about the hydrogen ? doesn’t that risk getting vented out with the steam ? into the barbecue ?
A hydrogen fuel cell also vents and you can ignite the concentrated stream like a blow torch. At 5% the pressure of a H fuel cell, the battery probably vents less hydrogen.
I laughed, but is that really true? You're going to have a lot of batteries/cells in one place, and one will inevitably start barbecue. Isn't the question whether the rest joins?
I suppose it is probably hard to engineer a battery that is prone to spontaneous barbecues but resistant to the influence of outside barbecues. But I'm not sure I agree that it's just a numbers game that if you put enough of something in one spot, some of them are bound to suddenly catch fire without outside intervention.
Re-reading the article, it sounds like maybe the venting happens at some pressure high enough above the point at which H reacts back to H2O that there’s none left ?
Can anyone comment on the design of the cell, specifically why it is long and thin, which would work against the square cube law. Is a large surface to volume chosen for thermal reasons?
As I understand it, something like a lead-acid battery using volumes of acid and volumes of reactants so a cube gives them more power with the same surface area. NiMH batteries use boundaries between states instead of acid. Therefore, you want long thin batteries of alternating materials to make them more efficient.
Or, to put it a different way, NiMH batteries require a large interior surface area, and so the square/cube law forces them to look longer and thinner as they get larger.
As per the article, these Nickel Hydrogen batteries are very different to NiMH
> Nickel-hydrogen batteries look and work unlike any other battery. They consist of a stack of electrodes inside a pressurized gas tank. The cathode is nickel hydroxide while the anode is hydrogen. When the battery is charging, a catalytic reaction generates hydrogen gas. During discharge, the hydrogen oxidizes and converts back to water.
The cells are pressure vessels, so normal cube-square scaling laws don't apply. Instead you need to use pressure vessel scaling laws, which also account for the needed wall thickness.
Pressure vessel scaling laws say that all cylinders have the same mass efficiency, and making long thin cylinders is easier than making short squat cylinders.
It's strange they didn't compare these batteries to lithium titanate, which is the other chemistry that can do 30,000 cycles and is something anyone can buy right now. They have extremely high charging C rates and sit somewhere between normal batteries and full capacitors in what they can do. They end up being about 50% more than LiFePo batteries in cost.
The numbers thrown out for this (~$60/kWh) are comparable in price to what LFP might cost in the next couple of years, the C rates for these are much lower (C/2).
The use case for this is to charge the battery during the day and discharge it during the night. It is not for seasonal energy storage. There are no batteries that can be used for seasonal storage, nothing comes within a factor of 100 of being economical. But batteries for seasonal storage requires very few cycles, one per year. This battery here can go through many thousands of cycles. If you don't use it for daily storage, you are paying for something you don't need.
When they are at full charge, they have H2 at 300PSI. Assuming they spend a significant fraction of a day at full-charge, after 10 years they will have totaled a significant fraction of 10 years at 300PSI.
GP's question is "Will the H2 migrate through the pressure tank after such a long time?"
Since it's relatively low pressure (5% of a hydrogen fuel cell), couldn't they have larger batteries for grids? The current size would be great for homes.
That looks suspiciously similar to a standard gas tank size.
Generally you make a battery by combining cells - they have a 1-1.5V terminal voltage. The image lower down shows a rack of them in a warehouse. I suspect you'd stack them up to a few hundred volts and plug them into an inverter.
I wonder if they require the same balancing as more delicate chemistries.
I'm curious how they solved the hydrogen leakage/seepage problem through the walls. Even though it is designed for many (daily?) cycles and not long-term storage, it seems that H2 is in the tank anytime there's a charge ready or building. Maybe the pressures are low enough that it's insignificant even over 30k cycles?
Or does it just require occasional recharging with water or H2, and if so, what is the value of "occasional"?
> So far, EnerVenue has been operating a pilot production line that can manufacture 100 megawatt-hours’ worth of batteries per year—and they’ve deployed small-scale test systems. But, says Heinemann, the company already has over 7 GWh, or about 400 million dollars’ worth of purchase orders...
We should soon see if this is a viable business then.
This implies a bulk cost of about $57/kWh which is slightly cheaper than present day LFP (the primary competitor for grid-scale battery storage). IMO, it needs to be no more expensive than LFP, because LFP cells can be spec'd for ~8 years and it's hard to get people to invest on timescales longer than ~10 years.
There are many grid battery technologies common on right now, liquid metal battery, IronAir battery and many more. And all of those have lots of 'orders' that they brag about.
I visited the NASA campus in Cleveland, OH many years back and got to talking to one of the engineers who worked on this tech for the ISS. The batteries they use up there run $10k a piece, but he stressed how rock solid the chemistry and design is.
Nickel hydrogen has incredible endurance, but the part that really struck home with me: they measure the state of charge with a pressure gauge.
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[ 5.1 ms ] story [ 372 ms ] threadFor cars and trucks, current batteries are actually fine. Higher energy densities are mainly nice for things like high end sports cars where the form factor prevents cramming in more battery. But less so in freight trucks. Saving a few hundred kilos of mass on a truck that pulls 80 tonne is just not that valuable. It's nice but only if it doesn't raise the price too much. So what if you need a two tonne battery? The main constraint here is cost, not weight.
The aviation market on the other hand has an insatiable demand for high energy density storage. Hence companies like CATL announcing 500wh/kg batteries recently. That's double what you'd find in a high end car these days. And apparently they are working on even higher energy density batteries already.
Probably these are really expensive and hard to get. But it's going to add quite a bit of range to things like VTOL planes, drones, and other flying things that run on batteries. So, a NASA battery with high energy density and a few other nice properties (like needing no cooling/heating) could be worth the extra cost in this market. And better longevity means more time in between expensive overhauls as well.
From my understanding of the trucking industry, in many sectors, this isn't true at all. For example, in tipper trucks where you are carrying literal dirt and rocks from one place to another every kg counts and tare weight of the truck is very much a consideration, even in the relatively minor variations between diesel trucks.
In the US weight restrictions are even lower than in Europe in many states.
Given that road wear grows to the fourth power (!) with vehicle weight, I hope you guys feel well with the fact that your tax dollar subsidizes those ultra heavy trucks.
Retail stores certainly existed before the automobile. People walked, biked or used horses to get to them. Horse and cart were used to deliver things to them.
But this isn't really the right debate. Sure you need some last mile in many cases, but that's also often true with large trucks.
The simple fact is a far, far, far larger amount of transport could be handled by train if society put the right insensitive in place, rather then the completely backwards intensives that exist now.
In Switzerland its quite common for example to have even fresh food transported by train, the largest retailer works closely with the rail company and delivers to a number of regional depots where smaller (sometimes small or medium) trucks then take it to individual stores. We don't have these Wallmarkt supper stores that Americans (unfortunately for them prefer).
Its very common that larger stores, like Ikea actually are directly connected by the train network.
There could actually also be a lot more done to do cargo delivery by tram. This has started in a number of European cities. In Zürich the Cargo tram is currently mostly used for extraction of waste (like e-waste), not yet delivery, but it has potential.
Why haven't you told me earlier? I wouldn't have had to bother to walk to the supermarket across the street.
By contrast on American interstates the standard is 80,000lbs.
Your sarcasm is unwarranted and just makes you look stupid when you are completely wrong.
Divided by tire. That's why heavy trucks have so many of them.
Most countries regulate the weight by tire, so that this actually doesn't change between trucks.
On practice the impact of the truck is determined by law independently of the weight (on those superficial models, but there is also some depth where the regulation starts to fail).
Where can we find more on this? I'm not doubting, but I can't think of why this is. It's pretty rare to find much in the physical world that uses the 4th power (Hagen–Poiseuille equation relating fluid pressure differential in a pipe - or artery - is one of the few that comes to mind)
Weight savings are nice of course. But so is not burning diesel by the hundreds of gallons. The trade off is between a few percent extra weight or lots of dollars spent on fuel.
Weight is very very valuable on both passenger cars and commercial trucks. Hauling those extra 300-500kg vs a comparable size sedan comes at a steep cost too, as increasing weight requires stronger/wheels body, wheels, brakes, even engines.
There is a huge demand for higher energy density, preferably of a non-explosive kind.
https://dynomight.net/tires/
All I was trying to do is add some support to the claim that battery density does matter in cars (contrary to ancestor assertion). Less weight = less strain on brakes and tires = less nasties in the air and our lungs.
My car is at 150000 miles and it's still on the original set of brakepads. Some EVs actually have a problem with that, their brakes are used so infrequently that rotors start to rust. So automakers added firmware that periodically applies frictional brakes.
As cost of the batteries comes down, these things will only become more popular.
Check: North American Council for Freight Efficiency (NACFE)
See:
https://electrek.co/2023/09/12/tesla-semi-proves-itself-fasc...
Not all data is out yet but the idea that electric trucks can drive useful range without anything but chips is complete nonsense.
The gigantic of track transports are blow 300 miles and a Tesla Semi can handle that under full load and difficult circumstances.
https://www.cnbc.com/2022/12/16/pepsico-is-using-36-tesla-se...
https://futurism.com/the-byte/tesla-semi-range-potato-chips
Also the most common car in Europe (Dacia Sandero), which is a 5-seater only weights 1 036kg. Gigantic American cars are a cultural phenomenon (which is mostly ad-driven by the way), it doesn't relate to an actual need.
Source for that? From this 2015 study[1], it doesn't seems to be the case at all in practice. (And maybe it the safety regulation has tightened up in the US since 2015, but the car size difference had already existed for at least the past 2 decades at this point). In any case, given the car fatality rate in the US compared to the EU[2], these regulation seem pretty ineffective (no amount of car safety can compensate for the very low driving skill in the US, caused by very lenient driving license requirements compared to European ones).
Also, I don't know how US safety rules apply but that would be pretty stupid if cars capped to 50km/h were subject to the same requirements as highway-ready cars.
[1]: https://spectrum.ieee.org/us-european-cars-show-safety-diffe...
[2]: https://data.oecd.org/transport/road-accidents.htm
I used to work in automotive assembly as a robotics engineer. Besides being well-known in the automotive industry, it doesn't take a lot of internet sleuthing to find.
"In general, there are two reasons why late-model cars are much heavier than their predecessors: safety and convenience."[1]
"The U.S. has a bunch of extra safety standards that the Europeans don't. For instance, in America, car makers have to design airbags to protect people who are not wearing their seatbelt. In Europe, they just assume that everyone's buckled up."[2]
I think you're conflating standards and the result of those standards with your links. You can levy a bunch of requirements that drive up weight and also don't have a meaningful impact on safety. We might even agree that they requirements aren't particularly effective, but that doesn't mean the manufacturers can skirt them. Whether or not the standards work, the result is the same: heavier vehicles.
>I don't know how US safety rules apply but that would be pretty stupid if cars capped to 50km/h were subject to the same requirements as highway-ready cars.
The market for those vehicles in the U.S. is extremely niche, generally relegated to ATVs. So much of the U.S. is connected by highways that there's very few people who a) want/need to own a car and b) also have no need to travel on the highways. People who only want a small urban commuter will often just get a scooter or motorcycle.
[1]https://www.jdpower.com/cars/shopping-guides/why-are-modern-....)
[2]https://www.npr.org/2015/10/16/449090584/why-arent-auto-safe...
Even if it's not mandatory, basically all cars have airbags in Europe nowadays, including tiny cars.
> [1]https://www.jdpower.com/cars/shopping-guides/why-are-modern-....)
Come on: “By law, modern vehicles are required to be fitted with a variety of safety-oriented technology (anti-lock brakes, stability control and tire-pressure-monitoring systems, etc.) and equipment (air bags,laminated glass, door intrusion beams, etc.)” not only these things are also mandatory in Europe, all the given examples aren't even heavy to begin with!
> The market for those vehicles in the U.S. is extremely niche, generally relegated to ATVs. So much of the U.S. is connected by highways that there's very few people who a) want/need to own a car and b) also have no need to travel on the highways. People who only want a small urban commuter will often just get a scooter or motorcycle.
Yet American only commute 20 miles per day on average (at an average 30mph). The fact that highways in cities are “technically highways” is only a cultural (and political) decision: the same kinds of roads in Europe are in fact not highways and speed is often limited to 70km/h for instance in France.
Anyway there are highway-ready cars (with airbags, ABS and all) that weight less than 900kg in Europe (Renault Twingo, Fiat 500, etc.).
Even if the cars all have airbags, it doesn’t mean they can pass US crash tests. That means they can’t nearly even be offered in the US. For example, EU frontal crash tests use a deformable barrier while the US does not. Relating to the study received for your safety assessment, it says the distribution of differences overlaps with zero. That’s a red flag that you can’t make a claim that they are any didn’t different.
Your claim about US commits is incorrect and less than half of the actual value in both distance and speed. Avg. speed is also not an appropriate metric.
I could go on, but there’s a lot to unpack. The latter point is that I’m not convinced you actually understand the differences between US or EU car manufacturing or parts of US culture that drive some of those decisions. There’s certainly an overrepresentation of SUV and trucks as commuter vehicles but there’s also a huge portion of the population, especially in the vast rural population, who have legitimate and pragmatic reasons to these vehicles. (And that’s coming from someone who drives a small hatchback)
Bruh, if you're gonna make statements like this, your argument needs to be stellar to back it up. And then you go:
> especially in the vast rural population
The US rural population is tiny, it's less than 20%, it's the same kind of argument as “people have families” when barely any household is more than 4 people.
The reason why almost 70% of people are driving an SUV or a truck has nothing to to with families (90% of which fit in a four-sitter) or the needs of rural life (that's also why pickup truck's bed has shrank so much over the past 5 decades). In fact, the growth in usage of these cars happened coincidentally to the decline of rural population and large families.
Your focus on safety as the root cause is also pretty dumb, since any SUV from the 90s would fail European current safety tests anyway, despite being enormous already.
> Your claim about US commits is incorrect and less than half of the actual value in both distance and speed.
Please provide your sources, because it doesn't match with what I could find online. (I realize that I made a calculation mistake: it's 20 miles and an hour in average so 20mph).
> Avg. speed is also not an appropriate metric.
Yes it is indeed. It's not perfect, but it's still appropriate, because it means that the commute time is driven by traffic congestion, and even your car going up to max speed for a small part of your trip isn't going to save you much time.
Well, for starters, did you actually look into the studies you cited or did you just take the first parts that confirmed your bias? For instance, the study that claimed European cars are safer in front/side crash tests admitted that the distribution of safety differences contains zero. It's important to understand the limitations of null-hypothesis testing. This means you can't discount that there is no actual difference between safety. This is why data literacy is important rather than just reading the abstract or conclusion and running with it.
>The US rural population is tiny, it's less than 20%
Again, this belies ignorance. Did you just grab the first Google result that confirmed your stance, or did you actually take time to understand the nuance? There is a massive disparity between what the census defines as rural vs. what is colloquially understood as rural. The census considers any population over 2500 people as an "urban cluster". That means US urban areas range from 2500-19.5MM. With that level of variance, you have to acknowledge large variance of “normal” use cases.
>Your focus on safety as the root cause is also pretty dumb
Please point to where I said it's the "root cause." I've only been advocating a more nuanced perspective. Also, see the HN guidelines for appropriate comments.
>Please provide your sources
The average round-trip commute as 55.2 minutes according to the US census and over 40 miles. Maybe you misspoke when you said "20 miles per day" and meant one-way?
>Yes it is indeed.
No, it's misguided and lacking nuance at best. Have you ever driven in southern California during rush hour? Your average speed is easily 30mph or less because you are essentially in a parking lot for huge periods. But that doesn't negate the need for a car to be able to reach highway speeds. Remember, the context was about safety of cars that are capped at 50km/hr, but now you're moving the goalposts and acknowledging the need for faster speeds just to maintain your position.
It's pretty clear you have your mind made up and prefer to argue rather than have a substantive and nuanced conversation.
Coming from the author of “you’re speaking from a place of ignorance” (+ other variations), I can only hope you're trolling at this point.
> This means you can't discount that there is no actual difference between safety. This is why data literacy is important rather than just reading the abstract or conclusion and running with it.
Given that the argument being refuted was “US cars are safer” the “no actual difference” case still counts as a refutation. How good is data literacy if you lack logical reasoning abilities…
> The census considers any population over 2500 people as an "urban cluster"
In an area were more than 2500 people live you'll most likely have actual roads and bridges, and don't need a truck to cross rivers or to drive on unpaved roads, so the definition is pretty much on point when we're talking about cars! And then 71% of the US population live in urban areas of more than 50k inhabitants so the smallest urban areas are in fact a small fraction of the total urban population (Edit: In any case, urban population living in areas with less than 10k is just 7M[1] so it's not these 2% of the US pop who make the car market either…). But yeah, I'm the one suffering from confirmation bias…
> Please point to where I said it's the "root cause."
Sure, here it is: https://news.ycombinator.com/item?id=37674080 you're welcome.
> But that doesn't negate the need for a car to be able to reach highway speeds.
Sure, one car able to go to highway speed for vacations and all. But must households don't need two of such cars!
> Remember, the context was about safety of cars that are capped at 50km/hr, but now you're moving the goalposts and acknowledging the need for faster speeds just to maintain your position.
Nope, the context is here: https://news.ycombinator.com/item?id=37658823 and I'm talking about both the Ami and the Sandero.
> It's pretty clear you have your mind made up and prefer to argue rather than have a substantive and nuanced conversation.
Cause you don't lack nuance at all ;).
[1]: https://www.federalregister.gov/documents/2022/12/29/2022-28...
There is no root cause claim there so you’re not saying much, other than strawmanning. If you look at a modern economy car, it weighs more than economy cars of the past or non-approved models for the US, despite using lighter weight materials for comparable components. So where does the extra weight come from? Mandatory safety features and options. That’s all the “disproportionate” statement is saying. It also wasn’t a comment to you, so a bit cringey that you try to search for any weak handhold to make your point.
You also picked a different comment to illustrate the context rather than your actual post, so I’m not sure your point. But it certainly lends credence to the idea of you moving the goalposts just to avoid being wrong.
I’ll give you more perspective since you missed the point. If the data contains zero it means it ranges from saying the US cars are safer to saying they are less safe. Zero is contained because it’s within this range. In other words, you can’t make strong claims at all. Again, data literacy is important.
> If you look at a modern economy car, it weighs more than economy cars of the past or non-approved models for the US, despite using lighter weight materials for comparable components. So where does the extra weight come from?
Ah yes, because your old car also had AC, electric window, and all the comfort a modern car has (including the car's form factor, giving more room for arms and legs, and less effort to get out of the car), and then the only difference must be safety…
> You also picked a different comment to illustrate the context rather than your actual post
Yes I took an adjacent comment in the same thread that you posted 5 minutes before your response to mine. So that must count as a completely different context, right? No, and you know it as well.
> If the data contains zero it means it ranges from saying the US cars are safer to saying they are less safe. Zero is contained because it’s within this range. In other words, you can’t make strong claims at all.
Of course you can make strong claims, and you're even making a strong claim yourself right now! The claim I make (which is ironically the same as the one you're making right now) is that the study shows that you can't make a strong claim about the US safety being higher than the one in the EU. Which was your argument!
I know there are steep tariffs on Chinese EVs but I’m also wondering if these “cute little EVs” would pass US road safety tests. A disproportionate amount of weight in modern cars is safety equipment.
Disagree. Car and truck makers try to optimize for grams and saving a kg of production vehicle is considered a huge engineering victory. Saving 100s of kg is a gigantic deal.
I think LFP is basically already under that as well (I think they are in the 60-70/kwhr range).
For grid storage, that is probably the only metric that matters: cost per kwhr of storage (and sufficient cycle endurance).
So you didn't read the article? The piece states: "Yi Cui’s team found an inexpensive nickel-molybdenum-cobalt alloy catalyst for the battery that costs $20/kg." For a catalyst, that doesn't sound too expensive.
> Their published research cites a $~83/kWh cost for just the materials (that's not very cheap)
That's all very nice, but that number is from a paper from 2018. And they state that it is the battery cost: "The estimated cost of the nickel-hydrogen battery reaches as low as ∼$83 per kilowatt-hour".
And pulling up 2018 data for LiIon, we get $~198/kWh.. (For instance, from here: https://about.bnef.com/blog/lithium-ion-battery-pack-prices-...)
Part of my critique is that the numbers cited in the article don't relate to their meaning. Measuring catalyst by kg instead of kWh is stupid, so $20/kg means jack when you look at what that actually means for a battery. Sounds hard to believe that there is an inexpensive anything made of only things like nickel-molybdenum-cobalt.
> That's all very nice, but that number is from a paper from 2018.
Hey I agree with you, but that's what the article cited. Maybe they shouldn't be citing a 2018 article. And I bet that $83/kWh was absolutely a best case estimate without manufacturing costs, nor accounting for scaling costs. Thats why I added the link for context.
> We take the battery, put it in an open fire, and watch it continue to heat up. What ends up happening is that the pressure above top charge will force the hydrogen back into water. And then we have a release valve designed into the unit so at a predesigned pressure and temperature that will release, and you’ll get a steam vent.”
But what about the hydrogen ? doesn’t that risk getting vented out with the steam ? into the barbecue ?
What’s the self discharge characteristics ?
Doesn’t it say the hydrogen is vented as H2O?
Or, to put it a different way, NiMH batteries require a large interior surface area, and so the square/cube law forces them to look longer and thinner as they get larger.
> Nickel-hydrogen batteries look and work unlike any other battery. They consist of a stack of electrodes inside a pressurized gas tank. The cathode is nickel hydroxide while the anode is hydrogen. When the battery is charging, a catalytic reaction generates hydrogen gas. During discharge, the hydrogen oxidizes and converts back to water.
See this diagram: https://en.wikipedia.org/wiki/File:Nickel-hydrogen_battery_N...
Pressure vessel scaling laws say that all cylinders have the same mass efficiency, and making long thin cylinders is easier than making short squat cylinders.
GP's question is "Will the H2 migrate through the pressure tank after such a long time?"
Generally you make a battery by combining cells - they have a 1-1.5V terminal voltage. The image lower down shows a rack of them in a warehouse. I suspect you'd stack them up to a few hundred volts and plug them into an inverter.
I wonder if they require the same balancing as more delicate chemistries.
1. No thermal runaway and "phenomenal overcharge, discharge and deep-cycle performance"
2. "Flexible charge and discharge rates"
3. "Vessels can discharge to 100%"
4. Specified charging rate of C/12-C/2 (i.e. can be charged at rates from 1/12 the capacity per hour to 1/2 the capacity per hour)
They do require usage of a tiered BMS though: https://enervenue.wpenginepowered.com/wp-content/uploads/202...
But, keep in mind that Undecided is overly optimistic about pretty much every emerging technology.
Or does it just require occasional recharging with water or H2, and if so, what is the value of "occasional"?
We should soon see if this is a viable business then.
This implies a bulk cost of about $57/kWh which is slightly cheaper than present day LFP (the primary competitor for grid-scale battery storage). IMO, it needs to be no more expensive than LFP, because LFP cells can be spec'd for ~8 years and it's hard to get people to invest on timescales longer than ~10 years.
Nickel hydrogen has incredible endurance, but the part that really struck home with me: they measure the state of charge with a pressure gauge.