> I know folks are saying Trevor and Nikola Motors have some sort of ground breaking hydrogen tech
So, they have "ground breaking tech" in a dead-end technology then? The energy losses required to power vehicles with hydrogen are much greater than losses with electric batteries (there was a recent article on HN that really drove this point home for me). Seems like the only folks pushing hydrogen these days are folks that made bets on what turned out to be the wrong tech (cough, cough, Toyota).
My opinion is that long-haul trucking is pretty much the only application where Hydrogen propulsion could make sense: Refueling infra only needs to cover truck stops (much more geographically consolidated compared to passenger cars). Autonomous driving tech would made it possible to run 24x7 (given recent advances, this is no longer a pipe dream), so BEV long recharge times would eat into uptime, but H2 refill won't (compared to diesel). Heck, if some kind of ICE could support flexible H2/LPG/CNG fuel, it's still gonna be much better than diesel + DEF.
BEV is perfect for trucking - you’re sleeping on the road. Just have to be sure to have enough spots at Love’s or TA. The market will work that part out.
I like hydrogen. The idea that every personal vehicle should have 1000 pounds of lithium-cobalt-etc is crazy to me, that's before getting into super-trucks and 18 wheelers, then not to mention aircraft and cargo ships.
> Modern vehicle weigh multiple tons, what's a half-ton battery really matter?
The Tesla Model S weights about 2100kg.
The Tesla Model S battery weights about 540kg.
This means that a 1500kg car is forced to pack an additional 540kg to be able to store energy. That's an additional 30% of the mass that you need to accelerate and brake.
People do care about that. In the very least, the battery mass is responsible for an effective drop in energy efficiency of around 30% just to cart someone around.
> Finally, electric cars charge at ~96% efficiency, while hydrogen is something like 40%. I, for one, am not interested in paying 3x per mile.
This claim has little substance and credibility. For starters, if you factor in how much additional energy you need to waste just to pack along a massive half ton battery, you'll eventually realize that the effective energy waste of a EV is not much different than the hydrogen one.
I mean, the point of a EV is not to have it parked on the driveway, charge a battery, and proceed to boast about how that was very efficient. Your goal is to move around, and moving that massive half ton beast of a battery along with you wastes a lot of energy too.
Also, battery efficiency is around 80%, which naively sounds a far improvement over fuel cell's lauded 40% efficiency. However, a Li-Ion battery weights half a ton and represents around 1/3 of a EV's mass, which also requires energy to be moved around. For reference the fuel cell of a Toyota Mirai is only 40kg, less than the weight of an adult passenger. Once you do your math you'll quickly notice the effective energy use is not that different.
And then there's the cost argument. The typical back-of-the-napkin figure for how much EVs cost to run is around 500€/year. Even if you bump that up to twice the cost, that price is eclipsed by the huge markup that you're already paying for an EV. I mean, a Tesla Model S costs about a century worth of energy bills before it even gets it's tires dirty.
Playing the frugality card with the current batch of EVs lacks any credibility and is, at best, being penny wise and pound foolish.
> This means that a 1500kg car is forced to pack an additional 540kg to be able to store energy.
I think this is the wrong angle to look at the issue.
A 2100kg EV requires 25% of its total mass to support the energy storage, generation and transfer in order to provide a range and performance profile people are generally happy with.
What is the fraction for a new ICE vehicle with similar profile? The combustion engine weighs... how much? Then add the weight of a 60% full fuel tank to allow for roughly the average deadweight haul between refills. Then include the weight of the exhaust system.
And finally, we have to include the weight of the drivetrain. How much of the total weight in an ICE is dedicated to power transfer from engine to wheels? How much in a modern EV?
Energy storage and generation is only a part of the picture, getting it to the wheels is what makes a car actually perform its function. We should include these numbers to get a meaningful comparison.
> Finally, electric cars charge at ~96% efficiency, while hydrogen is something like 40%.
>> This claim has little substance and credibility.
The efficiency of hydrogen fuel cell vehicles versus battery vehicles is considered in some detail in this video [1]. The conclusion [2] is that, in the best case, the energy efficiency from power generation to road for existing or near future hydrogen fuel cell vehicles is about 25%, compared to about 65% for typical existing battery vehicles.
> In the very least, the battery mass is responsible for an effective drop in energy efficiency of around 30% just to cart someone around.
It's not nearly as simple as that because electric cars have regenerative braking, and because the energy doesn't all go into acceleration. A lot (probably most, depending on how you drive) goes into wind/rolling resistance at a constant speed and that doesn't depend much on mass.
It's not a good idea to conjecture and argue from total ignorance. There are commonly used battery chemistries, such as LiFePO4/graphite, that simply do not use any scarce resources.
Other materials are mildly better and not too scarce. Tesla is moving some of it's production to LFP, but that's probably mostly because they want to scale up production faster than nickel mining can scale.
Lithium is not a scarce resource. This is pretty obvious because when looking at commodity prices lithium is measured in $/metric ton rather than actually scarce elements like gold where the price is in $/troy ounce.
> The idea that every personal vehicle should have 1000 pounds of lithium-cobalt-etc is crazy to me
Whether it seems crazy is evidence of unfamiliarity, not whether it is actually crazy. Is it really any crazier that continually pumping every car with juice made from literal fossils?
At least the battery is continually reusable — and at the end of its useful life, over 90% recyclable.
They can be almost 100% reused. In fact, given how valuable the metals are it would be cheaper to do so than mine for them . There are multiple companies working on this. E.g. https://www.redwoodmaterials.com/
I was hoping we’d just make synthetic gasoline from atmospheric carbon dioxide. Wouldn’t require changing any infrastructure at all. Just make gibs of it using renewables. It sounds good in theory anyway.
One of the nice aspects of electric cars is going to be eliminating city polution and reducing road noise.
I have no idea what the CO2 impact would be and don't really care that much ("cutting CO2 will reset the climate to some state we like" sounds like wishful thinking and most of the talk in this space is ideologically coloured I don't even want to pay attention) but the improvement in urban living is going to be undeniable.
> but the improvement in urban living is going to be undeniable.
When the pandemic arrived here back in March 2020, and nearly everyone suddenly stopped leaving their home, it was eerie: the air where I live (in the middle of a major urban area) suddenly smelled as if I was in a rural area. It was something I wasn't expecting to see so soon; I have for a long time been rooting for EVs to arrive and make the air quality better, but unfortunately EVs are simply way too expensive yet (so far, I only have seen an EV once, and it was an i3 with a range extender; and I do live in a major metropolitan area).
aside from accelerating at stoplights, electric cars and gas cars make similar noise levels just from the rubber against the road. rubber is a significant pollutant as well, as is brake dust.
Don’t get me wrong, electric is much better, i’m only nitpicking since you said “eliminating”
Brake dust is much less of an issue with electrics too, but agreed that tires are still a factor. But as someone who lived in urban centers for the majority of his life - I think getting down to tires being the major issue is solving the majority of the problem.
> So, they have "ground breaking tech" in a dead-end technology then? The energy losses required to power vehicles with hydrogen are much greater than losses with electric batteries (there was a recent article on HN that really drove this point home for me).
These comments show a failure to understand what does hydrogen mean and why did it popped up as an alternative to ICEs to begin with.
Hydrogen is presented as an alternative energy store that is clean, renewable, and can leverage existing infrastructure and, perhaps more importantly, consumer patterns and mental models, with little to no change.
Energy efficiency is not a concern with hydrogen, or even a relevant talking point, because the promise of being able to generate it through renewable sources means it has no implication on its carbon footprint or even pollution. Also, it was a topic that was actively being researched and thus, much like photovoltaic panels, its efficiency was likely to go up.
We also need to keep in mind that hydrogen was closest to production and mass adoption a few years ago, and we need to remind ourselves that not so long ago the idea of widespread supercharger stations and affordable electric batteries with enough storage to power a small family car was very close to a pipe dream.
In my opinion, the only reason hydrogen why hydrogen hasn't been mass adopted was the colossal investment in marketing and R&D that a few private companies made in electric vehicles in general and Li-Ion batteries in particular. In the future we might very well look back at hydrogen in a similar way that a few years ago, when ICEs were the only game in town, we looked at the EVs from the late 19th/early 20th century and we wondered why were we so close but still missed the boat.
Energy efficiency is important relative to other distribution methods. If the efficiency is half that of electric, you can power half the cars you could with electric with existing energy supplies. Obviously that is incredibly important - energy supplies will always be finite and fully utilised.
A few places have tried to build a hydrogen network with. Metal embrittlement is a real problem and storage is not straightforward, even after you've produced it.
Hydrogen hasn't been adopted because it is expensive, dangerous, difficult to store and not as efficient as electric. With advances in batteries in the last few years it is definitely on the way out and electric is the clear winner here.
> Energy efficiency is important relative to other distribution methods.
The point is that energy efficiency is only one factor among all other. For example, it makes little difference if you blindly tag a 80% efficiency tag on a EV if afterwards you have to waste twice the energy to cart along a massive battery.
> If the efficiency is half that of electric, you can power half the cars you could with electric with existing energy supplies.
The point that you're missing is that said cars are also far heavier (the battery on a Tesla Model S weighs half a ton alone which contrasts with Toyota Mirai's 40kg fuel cell), which requires far more energy to move around. What matters is how much energy you actually waste while driving, because that's where all the energy is going.
> Hydrogen hasn't been adopted because it is expensive, dangerous, difficult to store and not as efficient as electric.
I disagree with any of those points, specially as some of them like the safety scaremongering are far-fetched, as they aren't really grounded on the real world.
The critical difference between EVs and hydrogen was that EVs benefitted from a fantastic marketing and PR push, investment in infrastructure and R&D effort from private companies pushing EVs that was able to budge the status quo and made them acceptable to the public in spite of their major drawbacks such as massive cost, autonomy restrictions, and long charging times.
This foot-in-the-door was further compounded by the way some states decided to invest heavily in EV subsidies and public infrastructure, which was completely absurd, unrealistic and politically impossible in the recent past.
EV's recent mass adoption acceptance is not a technical feat but a social and political one which happened to leverage a specific technology.
I'm not sure about Tesla, but according to specs I found, but Kia e-Niro with 400 km range is 1737 kilograms, 400 km range Hyundai Kona Electric is 1685, 500 km range WV ID3 is 1730 ... while Toyota Mirai is 1825 kg and my ICE Jaguar is 1950 kg.
Long story short, I'm not convinced it's so simple.
Energy efficiency is a major concern when you need literally three times the energy to achieve the same goal. Clen energy is already scarce, only places with a lot of nuclear have a semblance of it. BEV would already increase electricity demand a lot (grab vehicle-miles per year and turn it to TWh needed and see), doubling or tripling that would put the goal of decarbonization decades further away.
> Hydrogen is an energy store. It doesn't typically exist by itself in nature and must be produced.
I know hence the question.
to answer my question, which is also in the article you've kindly posted:
"Currently, most hydrogen is produced from fossil fuels, specifically natural gas"
Which is the point I'm getting at. Its cheaper to split natural gas than it is to do electrolysis.
What I have discovered is that state of the art electrolysis is about 80% which is far higher than I had remembered. Alas, fuel cells are still 40-60% efficient, so we could still be looking at terrible round trip efficiency.
Hydrogen might one day be the storage medium of choice, but its not yet. I suspect we'll have working fusion before we have practical grid scale hydrogen, let alone wide scale hydrogen cars.
But the losses going from electricity -> hydrogen (and then back), and then losses again in failing to recaputure energy into hydrogen on board - I mean, you will need to use a lot MORE "renewable" energy to get your hydrogen vehicle around.
When using renewables, losses don't matter. The matter a lot now, where the losses are covered with fossil fuels, but that's now where we're heading. Hydrogen fuel tanks are far cheaper and more sustainable than lithium batteries. I believe the power density is also superior, although I don't have time to check right now. Additionally, hydrogen fuel isn't only useful in vehicles and a more efficient production method would still be great to have.
So, they have "ground breaking tech" in a dead-end technology then? The energy losses required to power vehicles with hydrogen are much greater than losses with electric batteries (there was a recent article on HN that really drove this point home for me). Seems like the only folks pushing hydrogen these days are folks that made bets on what turned out to be the wrong tech (cough, cough, Toyota).