It's a novel way to store hydrogen instead of a traditional high pressure tank.
This is a teeny tiny problem for a hydrogen cars. It doesn't really address the problem that fuel cells are ridiculously expensive, or that there's no filling network, or that there's no good way to fill them at home, or that fuel cells are themselves only 50% efficient typically.
MOF-based hydrogen storage has been around since at least 2003 (Omar Yaghi on MOF-5). Its hardly a novel concept. I haven’t read this paper, I just skimmed for figure out what the “aluminum sponge” was until I saw it was Farha and MOFs. As far as I can tell, this is in Science because it surpasses key benchmarks set by the DOE, not because it’s a new idea.
This is a particularly high surface area MOF (>7300 m^2/g). I recently picked up a MOF project (not related to hydrogen storage) with derivatives of a popular MOF and it’s closer to 1000 m^2/g. Zeolites (a much more established class of porous material) are about a quarter of that (<200-300).
An actual metal sponge (what I thought the article was talking about) is <~20 m^2/g.
Basically everything you said is wrong. The costs of fuel cells are dropping so fast, that that is probably the main driver of interest in fuel cell technology recently. The filling stations are being installed by dozens around the world right now. Fuel cells have reach 60% efficiency in real world testing.
It’s been something of a blind spot among tech workers that they are completely oblivious to the gains made in fuel cells. For all the hype about us being forward thinking, a lot of us are seriously stuck in the past.
It's not much of a blind spot. Fuel cells are worse for consumer cars than batteries, both in environmental terms and in terms of convenience. A BEV can recharge at home using existing standard outlets (a 240v 30A or 50A dryer outlet for good performance, or even a 120v regular outlet will do if you're willing to wait a while); good luck refilling a fuel cell.
BEVs are nearly 80% efficient already [1], are comparatively widely deployed, and the infrastructure for them exists in everyone's home. For long distance travel, there are far more fast chargers than hydrogen stations, and far more investment in building more of them.
Also, most independent real-world tests I've seen of hydrogen cells reported much lower efficiency in practice than claimed — often between 30-40%. The only tank-to-wheel 60% claim I could find was a statement by Honda of their own car; FWIW, the EPA rating of the latest, most-efficient version of that car (the Honda Clarity Fuel Cell) is actually 68 MPGe [2], which is much lower than most BEVs. In fact, the battery-based version of the same exact car, the Honda Clarity EV, has an EPA rating of 114 MPGe [3], which is nearly 70% more efficient.
Hydrogen fuel cells for consumer cars just don't make sense.
> It's not much of a blind spot. Fuel cells are worse for consumer cars than batteries, both in environmental terms and in terms of convenience. A BEV can recharge at home using existing standard outlets (a 240v 30A or 50A dryer outlet for good performance, or even a 120v regular outlet will do if you're willing to wait a while); good luck refilling a fuel cell.
And if you don't have a garage? Or park on the street? You're just hand-waving away a very consumer hostile problem. You have to assume that there will eventually be a hydrogen refueling network, at which point refueling is just 5 minutes for 300-400 miles of range.
> Also, most independent real-world tests I've seen of hydrogen cells reported much lower efficiency in practice than claimed — often between 30-40%. The only tank-to-wheel 60% claim I could find was a statement by Honda of their own car;
I doubt those tests you claim really exist. Hyundai claims their car also gets 60% efficiency [1].
> In fact, the battery-based version of the same exact car, the Honda Clarity EV, has an EPA rating of 114 MPGe [3], which is nearly 70% more efficient.
I don't doubt BEVs are more efficient. It's likely just irrelevant as we build out an insane about of renewable wind and solar. Right now, the problem is we are producing too much, not too little, renewable energy. The goal is to use that nearly free electricity to make hydrogen [2].
> And if you don't have a garage? Or park on the street?
Use a charging network; there are plenty (and there's far more investment in expanding them than hydrogen). Many malls and grocery stores have chargers in their parking lots reserved for EVs; you can charge while you shop.
> The goal is to use that nearly free electricity to make hydrogen
Sure, as an alternative at grid scale (which is what the link you posted references). But BEVs are more efficient, and simpler, for consumer cars. We already have an electrical grid. Even just transporting the hydrogen from the generator to the theoretical thousands of refueling stations would be inefficient and wasteful.
> Right now, the problem is we are producing too much, not too little, renewable energy
> Use a charging network; there are plenty (and there's far more investment in expanding them than hydrogen). Many malls and grocery stores have chargers in their parking lots reserved for EVs; you can charge while you shop.
This really kills the convenience argument though. If you must recharge using public stations, it is much less convenient that hydrogen stations that can do it in 5 minutes.
The study was conducted back in 2007, a time where fuel cell cars basically didn’t exist yet. I suppose this does qualify as “existing,” but it is not real world and is clearly wrong as of today.
Fuel cell cars today are at 60% regardless. This is also hard to dispute, since a 35% efficient fuel cell car cannot approach 68MPGe. So it is an outdated study at best.
> Sure, as an alternative at grid scale (which is what the link you posted references). But BEVs are more efficient, and simpler, for consumer cars. We already have an electrical grid. Even just transporting the hydrogen from the generator to the theoretical thousands of refueling stations would be inefficient and wasteful.
It costs very little to pipeline hydrogen around. This is not a problem if we have plenty of cheap hydrogen to go around.
> Less than 15% of America's energy comes from renewable sources.
It is much higher in states that invested in renewable energy. California is at 30% for instance. It’s even higher in some countries in Europe. What we’re finding is that power swings from >80% to less than 20% on a regular basis. This problem is addressed here: https://www.governing.com/next/Americas-Largest-Municipal-Ut...
> The study was conducted back in 2007, a time where fuel cell cars basically didn’t exist yet. I suppose this does qualify as “existing,” but it is not real world and is clearly wrong as of today.
The first study in the linked article was conducted in 2010. FWIW, Honda's study (which is the only one I can find a source for that claims 60% tank-to-wheel) was conducted in 2008.
> Fuel cell cars today are at 60% regardless.
Source? Ideally to an independent, real-world study. The EPA MPGe ratings have strongly disagreed with you that hydrogen is comparable to BEVs, as have the studies I've linked, so I'm curious where this 60% real-world claim is coming from.
> This is also hard to dispute, since a 35% efficient fuel cell car cannot approach 68MPGe.
EVs are generally able to get up to 77% efficiency in real-world usage, per the link I posted above. The Tesla Model 3, the most-efficient sedan in 2020 according to the US Dept of Energy [1], gets 141 MPGe.
If we assume the Model 3 is 77% efficient, that leaves the Honda Clarity Fuel Cell (which is rated at 68 MPGe) at approx 37% efficient, since MPGe is strictly a measure of average distance traveled per equivalent unit of energy used [2].
Better than pure gasoline, sure, but it's still pretty far from a BEV. Even hybrids get decently close to hydrogen; the Prius, for example, gets 56 MPG. BEVs absolutely smoke both in terms of efficiency.
> The first study in the linked article was conducted in 2010.
The first study states "greater than 45%." This is pure misdirection here.
> Source? Ideally to an independent, real-world study.
There are vast resources available [1]. Evidence suggests it is around 60% at the stack, and ~55% at the system level [2].
> EVs are generally able to get up to 77% efficiency in real-world usage, per the link I posted above. The Tesla Model 3, the most-efficient sedan in 2020 according to the US Dept of Energy [1], gets 141 MPGe.
That's wells-to-wheels figure. You're comparing very different figures. Also, that 141 MPGe figure is just them gaming the fuel economy test [3]. It is not showing up in real world testing.
Using basic physics (which assumes BEVs are 95% at the wheels vs 55% for FCEVs), the peak difference could only be 72%.
> Even hybrids get decently close to hydrogen; the Prius, for example, gets 56 MPG.
The Prius is a much smaller car than the Clarity. Not really a fair comparison.
EVs still have enormous CO2 lifecycle footprints, to the point that they're not really a solution to road traffic CO2 emissions. How does the lifetime footprint compare to hydrogen based cars?
Doing this would defeat the only advantage hydrogen has, which is rapid fueling. To add to the inconvenience, you'll need to plug in both the electricity, and a hose to your supply of distilled water.
Beyond that, the best case efficiency for such a hydrogen production process in an industrial setting is 80% (using a process which feeds waste heat back into the electrolysis reaction). From the hydrogen back to energy moving the wheels is at most 50% efficient, so a total plug to wheels efficiency of less than 40%. In the real world, it will be far less efficient than that (probably 25% at best), and very expensive to achieve in a practical car for sale, for the same reason that hydrogen fuel cells in cars are expensive today.
That vs the typical plug to wheels efficiency of around 60% in today's electric vehicles.
And such regenerative hydrogen fuel cells do not even exist for automotive applications today.
This paper has several lifecycle efficiency graphs that explain aspects of this in some detail:
The best case scenario like you described is about 98%. FYI, 80% is already being hit by real world normal electrolysis reactions.
It’s very likely we’re in the same position with fuel cell cars that solar was back in the late-2000s. Arguments that it is “too expensive” are really falling apart, especially considering that green hydrogen is around $2-3/kg today, and that platinum loading has dropped to around 10 grams for a car sized fuel cell.
> FYI, 80% is already being hit by real world normal electrolysis reactions.
Not in a fuel-cell running in reverse in a car, though, which is what the GP was referring to.
> especially considering that green hydrogen is around $2-3/kg today
More like $3-7 per kg today [1]. And as that article (which is less than 1 month old) points out, producing green hydrogen would require an absolutely massive buildout of renewables, which would better be put to direct use without the conversion penalty to hydrogen. Hydrogen energy storage will still have its niche applications on the margins, but it is unlikely to catch up to the cost and availability advantages of batteries for cars in places where the existing electric grid reaches.
> Not in a fuel-cell running in reverse in a car, though, which is what the GP was referring to.
It would make more sense to have a separate electrolyzer. This way, you can have a tank of hydrogen sitting around that can refuel your car in minutes, not hours. The original scenario is actually a bad idea.
> More like $3-7 per kg today [1]
You're rounding up to $3-7. It specifically refers to $2.50-6.80. Those higher figures aren't really going to stand for long as cheap green hydrogen displaces expensive green hydrogen.
> producing green hydrogen would require an absolutely massive buildout of renewables,
But we are massively building out renewables. In fact, we're building too much. During peak production times, renewable energy is literally just grounded since there is no use for it all.
> Hydrogen energy storage will still have its niche applications on the margins,
Hydrogen can be stored in salt domes in extraordinary quantities.[1] A single cavern can store 150,000 MWh of energy, and one formation in Utah can contain 100 caverns. That's something like 200 million BEVs worth of energy storage! As a niche, it's dominant one, and frankly hydrogen is easily going to be bigger in absolute metrics on that fact alone.
> but it is unlikely to catch up to the cost and availability advantages of batteries for cars in places where the existing electric grid reaches.
This is not a race. Fuel cell technology will still advance regardless of what happens of battery powered cars. Furthermore, nothing is close to the internal combustion engine in terms of marketshare. If it were a race, ICEVs are way ahead and neither BEVs nor FCEVs are anywhere close to winning.
> It would make more sense to have a separate electrolyzer.
A separate electrolyser and hydrogen storage at the household level just to fill up your car? It's doubtful that will make financial sense anytime in the near future, vs a plug.
> It specifically refers to $2.50-6.80.
You quoted $2-3 - in whole dollars - which are undoubtedly rounded figured themselves. How else would express $2.50-6.80 in whole dollars than $3-7?
> But we are massively building out renewables.
Not nearly enough to power ground transportation on green hydrogen, which was the point of the article I linked. On top of that, the tank-to-wheels efficiency of hydrogen fuel cell vehicles is 1/2 that of BEVs, which implies double the renewable electricity needed for green hydrogen vs directly using electricity in BEVs. It's better to keep ground transport as efficient as possible by using BEVs, and use the remaining electricity to synthesize fuels for applications like aviation that don't lend themselves to batteries due to weight constraints.
> A single cavern can store 150,000 MWh of energy, and one formation in Utah can contain 100 caverns.
There's a lot of "can" in that, similar to initiatives pushing carbon-capture from coal plants. I applaud it if it eventually works, but that article is a paid marketing release (note the "Mitsubishi Heavy Industries BRANDVOICE| Paid Program" at the top).
> This is not a race. Fuel cell technology will still advance regardless of what happens of battery powered cars
It is a race to which tech has a market viable product for cleanly fueled road transportation. Battery tech isn't sitting still either, especially on the rapid charging and range front. It's totally possible that hydrogen tech will come through with a series of breakthroughs that mitigate its current issues with cost, lack of distribution infra, but projections like the one in the article I shared put that out 10-20 years, and predicting anything past 10 years is a crapshoot anyways.
> If it were a race, ICEVs are way ahead and neither BEVs nor FCEVs are anywhere close to winning.
It's a race for the transportation tech of the future. Obviously ICEs are the majority of vehicles now, but that's hardly interesting to the debate about FCEVs vs BEVs, except in the matter of how much the gap between either of the new technologies and ICEs closes on the consumer price level.
> A separate electrolyser and hydrogen storage at the household level just to fill up your car? It's doubtful that will make financial sense anytime in the near future, vs a plug.
It will likely be akin to those people who put solar panels on their roofs and have backup power storage. Probably not for everyone, but for some groups of people it could make sense for them.
> Not nearly enough to power ground transportation on green hydrogen, which was the point of the article I linked. On top of that, the tank-to-wheels efficiency of hydrogen fuel cell vehicles is 1/2 that of BEVs, which implies double the renewable electricity needed for green hydrogen vs directly using electricity in BEVs. It's better to keep ground transport as efficient as possible by using BEVs, and use the remaining electricity to synthesize fuels for applications like aviation that don't lend themselves to batteries due to weight constraints.
If we’re already hitting majority renewable energy at their on peak on the grid, then we’re already on the verge of making too much. There are still huge solar and winds projects still being built, so it’s a guarantee we’ll make too much. Furthermore, we need backup energy storage to smooth out the intermittency. This is already being developed on using hydrogen.
Finally, I do hope you understand what synfuels are. They’re basically made from H2 and CO2, and having a huge H2 economy is a prerequisite to making them.
> There's a lot of "can" in that, similar to initiatives pushing carbon-capture from coal plants. I applaud it if it eventually works, but that article is a paid marketing release (note the "Mitsubishi Heavy Industries BRANDVOICE| Paid Program" at the top).
We were already storing hydrogen in this way for decades. This is a definite certainty that it can work. The question is whether there will be enough renewable hydrogen to fill the facility, not that it can’t work.
> It is a race to which tech has a market viable product for cleanly fueled road transportation. Battery tech isn't sitting still either, especially on the rapid charging and range front. It's totally possible that hydrogen tech will come through with a series of breakthroughs that mitigate its current issues with cost, lack of distribution infra, but projections like the one in the article I shared put that out 10-20 years, and predicting anything past 10 years is a crapshoot anyways.
> It's a race for the transportation tech of the future. Obviously ICEs are the majority of vehicles now, but that's hardly interesting to the debate about FCEVs vs BEVs, except in the matter of how much the gap between either of the new technologies and ICEs closes on the consumer price level.
The point being that BEVs can succeed, and still be displaced when FCEVs reaches a certain point. Moreover, neither are in any position to displace ICEVs yet. The most economical car you can by is some kind of ICEVs, especially if it is a hybrid of some sort.
I want to add that there are many sectors, such as large trucks, trains, ships, etc., that we are quite certain that batteries will never make sense in all likelihood. This pretty much requires we go the hydrogen route on them. That also makes refusing to invest in hydrogen equivalent to just giving up on reducing GHG in those sectors. So fuel cell technology is a necessary investment and not really optional.
> so a total plug to wheels efficiency of less than 40%. In the real world, it will be far less efficient than that (probably 25% at best).
> That vs the typical plug to wheels efficiency of around 60% in today's electric vehicles.
1) Just to add a point of comparison, current ICE engines have an efficiency of around 25-35%, so while 25% sounds bad, that's the technology we've been putting up with for a century. But obviously, new technologies ought to be more efficient.
2) Speaking of efficiency, here we are talking about plug-to-wheel efficiencies. The true useful efficiency of a car is the ability to move you to your destination.
So adding in the "weight efficiency" of 5-10%, given a 1-2t car and a 100kg charge (based on average 1.5 people occupancy in a car), the efficiency drops to ~1% for ICE/hydrogen cars and ~3% for electric cars.
Please consider using lighter cars, a lot more gains can be achieved that way.
The only reason that Hydrogen powered cars are even still discussed over battery electric is that 95% of industrial hydrogen is produced from fossil fuels. In other words the people pushing it are probably protecting their oil and gas interests. They aren't going to put money into research to cut themselves out of the loop.
But nobody is suggesting that industrial hydrogen will be natural gas based forever. Furthermore, we must have green hydrogen for steel and ammonia production. So this is a “must solve” problem no matter what.
This is basically the same kind of argument that BEVs are “secretly powered by coal.” These are backwards looking statements that are going to be wrong in the near future.
It is advantageous to get a foot hold in competitive markets, for sure.... but these actions are also heavily motivated by ulterior motives: tax credits, PR/marketing, lobbying, undermining competitive threats, etc.
Look, Shell is the third largest company in the world. They have many, many business interests. The idea that more EVs means Shell goes broke is pure fantasy.
Many more than 1/10 of those names are still dominant companies/brands, but some have gone through mergers or restructures, meaning the 1955 entity no longer exists but the business lives on and remains very strong.
BP and Shell are on that 1955 list, and are obviously still very strong companies.
According to the Lindy effect [1], the longer a company has existed, the longer it is likely to continue to exist.
Both BP and Shell have long been diversified companies (even in the 1950s, Shell had vast business activities outside of petroleum), and have long been investing heavily in various forms of alternative energy.
They're not likely to disappear in any foreseeable timeframe.
One issue is that you need a source of water. Another is that electrolysis is only around 70% efficient, whereas (say) lithium ion battery charging is more like 95% efficient.
I’ve always thought the distribution issue it’s the largest problem for alternative fuel vehicles.
Driving to Los Angeles from San Francisco is extremely difficult for either a fuel cell or ev vehicle (that’s not a Tesla, and it’s also true for cng vehicles). This is admittedly not a daily use case, but highlights the issues with refueling.
It’s hard to see either technology being our primary transportation mode without solving some of this. EVs have an advantage for fuel availability, but issues around fueling time.
I think there's a common misconception in your argument. Even without a full distribution network it might be a viable solution. Most of us use our cars for our daily commute, grocery shopping and other things within a fairly small radius. The few times we would need to drive the SF->LA distance you can easily take a rental.
The mistake is to assume that we would use "alternative fuel" vehicles the same way we would our petrol cars.
I don’t see how that’s a mistake at all from a customer perspective. You’re asking a consumer to buy something very expensive that in the past could do a whole bunch of things like go long distances, but now does less of those things. In exchange you provide them with more fuel efficiency? Maybe a good feeling about being environmentally sound? That’s not a good trade off in most customer’s minds.
Your response seems to be, “then rent for those occasions.” But that means the customer has to change their mindset, break long established habits. That’s a big ask.
If you’re Tesla you build a car that is better in every way than an old car EXCEPT mildly less convenient on range. Clearly that has legs, but lots of Tesla owners have a house/garage, and lots have another car, it’s not viable for a lot of people.
Hopefully alternative vehicles will improve to the point where there are no compromises, but until then I think it’s a fools errand to argue customers should just change how they think. They won’t unless forced to by outside pressures such as regulation or a massive change to the pricing structure of owning a regular car.
I don't think there's an assumption there. The alternative fuel cars that sell well are the long-range ones. Sure, people mostly drive them locally, but it appears to be the case that there's comfort in knowing that they can also go long distance.
I think 300 miles is a realistic minimum for viable EVs. At least in America. Because honestly, almost nobody gets anywhere near that except when they're trying to win Internet points. A 300 mile Tesla Model 3, depending on trim, is more realistically a 150-200 mile car, and some days won't even make it that far.
Source: I own a Tesla Model 3 Performance. For efficiency, the worst of them. Love the car, but saying it has 300 miles of range feels pretty dishonest.
I was surprised by your assertion that it would be difficult to drive an EV (non-Tesla) from LA to SF, so I did a quick search. It appears that there are regular charge points along I-5. I wouldn't be worried about it at all.
The total number of rapid charging stations is large and is increasing rapidly, while the total number of hydrogen is small and increasing slowly. It is quite certain this state of affairs is going to continue in the future, until eventually there are enough charging stations for everyone to go electric.
Gas stations here in Norway haven't primarily been about selling gas for quite a while, and most want to continue to get people to buy hot dogs, hamburgers, sodas and candy in the future. So they're installing fast chargers as well...
Except almost all fast charging stations on various Bergen-Oslo roads in Norway are not at the gas-stations. They are at the back of motels, souvenir shops, sometimes literally in the middle of nowhere with no shops or any other facilities to spend money- just a small parking place near mountain road.
> Driving to Los Angeles from San Francisco is extremely difficult for either a fuel cell or ev vehicle (that’s not a Tesla, and it’s also true for cng vehicles).
Maybe true for hydrogen, not so true for BEVs. There are plenty of CCS charging locations in the US and California in particular has many of them:
I had researched buying a CNG car in the LA area and bringing it back to San Jose. Reliable miles per tank data was tough to come by, but it seemed like if you couldn't use PG&E stations to fill (because it requires pre-registration, and a certified inspection), you wouldn't be able to take the most direct route.
That was for a crown victoria/lincoln town car though. I don't know if the civic's get more miles per tank.
Most "SUVs" are just station wagons with an extra inch of ground clearance. They aren't that heavy. A Prius, on the other hand is close to the weight of a light truck.
A Prius, on the other hand is close to the weight of a light truck.
I was real confused by this. Wiki says Prius is in the range of 3,000 lbs. Much lighter than a truck of any sort.
Perhaps you meant to say Tesla Model X instead of Prius? That the closest comparison to an SUV. It weighs in at well over 5,000 lbs, which closer to the range of a light truck.
He may have meant "small truck" instead of light truck? "light truck" has a specific definition and it's probably not what most people would think when using or hearing the term. A Prius is about the same weight as a lot of small trucks, or at least what small trucks used to be before the weird side-effects of fuel-efficiency regulations:
2005 Tacoma: 3,140 to 4,4100 lbs
2005 Ranger: 3,028 to 3,606 lbs
2003 S-10: 3,016 to 4,039 lbs
The best-selling Hyundai all-categories SUV in the US is the Hyundai Santa Fe and weighs in average 1.8t. The fact that there are lighter SUVs appearing on the market is encouraging, but your affirmation is most likely not true.
I’m sorry but this is basically just flame baiting. Just tossing in a zealous attack against large cars in the middle of a discussion on fuel cells... What is the interest in rehashing that same old debate in this thread?
Summary for those who didn't click on the link to the actual article [1]:
- a car may need 5 kg of hydrogen for a range of 500km (bbc's claim, I'll take it at face value)
- the new "sponge" material can offer "deliverable hydrogen capacities (14.0 weight %, 46.2 g liter−1) under a combined temperature and pressure swing (77 K/100 bar → 160 K/5 bar)."
- so for 5kg of H2 you need about 100 l of this material, at a weight of about 35 kg. Not too shabby.
- however, note the conditions: you store the H2 at 77k and 100bar. So you need liquid nitrogen and quite high pressure to hold this. That might add substantial weight to the 35kg of sponge
By the way, about one year ago, there was quite some big noise on HN about a different breakthrough from Australia, where some researchers showed economic ways to store H2 in ammonia. Not sure if that got anywhere.
Liquid anhydrous ammonia is already the obvious way to store and use hydrogen. It contains lots of hydrogen but doesn't have the embrittlement issues that elemental hydrogen does. Agricultural regions have extensive storage and distribution capacity due to its use as fertilizer, so no new technology is needed for handling ammonia. Common internal combustion engines can burn ammonia as fuel with minimal modification.
The only thing holding back the use of ammonia as energy storage is the fact that fossil fuels are still the most efficient feedstock. Once solar is more efficient, ammonia will see widespread production and use.
Which doesn't happen in the real world because of the way fuel tanks are constructed. Meanwhile, anhydrous ammonia is one of those things that give experienced hazmat workers nightmares.
Most of the people who safely use anhydrous ammonia on a regular basis are farmhands, not experienced hazmat workers. The training and equipment that allows them to do that would also be available to e.g. municipal bus lines or delivery companies. Any firm that hires people to refuel its vehicles could afford this. Eventually more fool-proof nozzles and storage tanks might be developed so that regular people with personal cars could safely handle this fuel, but it will be practical for other uses long before then.
Interestingly, the last time I heard an argument like this, it was being put forth in favor of using butane or propane as a replacement for CFC refrigerants in cars. That idea never caught on, but it's not clear if safety concerns in accidents were the reason.
At any rate, unless Farmer Brown regularly drives his fertilizer sprayer around on the farm at 70 MPH, I'm not convinced your analogy holds much more water than the anhydrous ammonia does.
Hydrogen is best thought of as an energy transfer mechanism -- an extremely lossy one at that -- not an energy source, and I don't see that changing anytime soon. It's hard to believe that ammonia-based storage is the missing factor in the hydrogen equation that we've all been searching for.
You have inconsistent fears. Presumably you mention 70mph because you're afraid of explosions from vehicle collisions. Yet ammonia is much less flammable (NFPA 1) than gasoline (3), and much much less flammable than elemental hydrogen (4). Ammonia is regularly used as a refrigerant and has been for longer than CFCs have existed. It is poisonous, but no more so than many gasoline additives and less so than tetraethyllead, which was a common additive until quite recently. More to the point, when burned in an engine it produces nitrogen and water, which are much safer than ICE exhaust.
No one is proposing hydrogen or ammonia as an energy source. There are no underground deposits. They will only make sense once solar generation is efficient enough that electrolysis becomes competitive with fossil fuels. We'll know that's coming soon when hydrogen hype artists are drowned out by engineers talking about ammonia.
Side note: common air duster can be used as refrigerant in old R12 systems used in cars until the early 1990s. there's a cheap "clamp" available online that punctures the duster can to tap it for the refrigerant. As far as i know, no modifications are needed to the old R12 system besides vacuuming out which any professional air conditioning technician can do.
Perhaps, though I once broke a 1L bottle of ammonium hydroxide (a strong solution of ammonia) in the lab. We literally couldn’t go in the room for 15 min. That was just 1L of not 100% ammonia, and we had a door where we could get out. Even if the ammonia isn’t flammable, you might kill occupants of a car with what is effectively a poison gas.
The main utility for ammonia is to transport energy long distances at industrial scale, not for individual vehicles.
So, for example, you'd build a huge solar farm where it's very sunny, or a huge wind farm where it's windy. And instead of running power lines, you'd ship ammonia.
> The main utility for ammonia is to transport energy long distances at industrial scale, not for individual vehicles.
Which is exactly how it was pitched in Australia, by the government agency responsible for developing it. It was the reason it was funded.
As I recall, it was "it solar continues current downward trajectory, it will be cheaper make than it is to frack natural gas". They seemed pretty convinced of it.
Only for short distances. At long distances, they lose power due to resistance in the wires. Underwater power lines across oceans are also extreme expensive.
Sometimes you don't have the luxury of a power line, e.g. in developing countries. Similar thing (larger scale though) happened with oil: there are still tons of oil tanks sailing around the world because a stable pipeline network is hard to build.
You're right that there's a reason we constantly transport so much liquid fuel around the world.
But the Europe and North Africa connection is already a relatively serious proposal precisely because of the efficiency gains. It's definitely an ambitious project, but more from the politics than from the technology. Electrons are just easier than atoms, even underwater. HVDC has made long distances realistic for cables.
China's Anhui to Xinjiang HVDC link will be around 2000 miles. There's a planned HVDC submarine cable from Lincolnshire to Denmark that will be 472 miles.
So for Australia to China, we might be able to pull off Darwin to Jakarta, then Jakarta to Hong Kong within 10-20 years, if you really wanted to. Would break some records, but it's not crazy impractical.
Though with the most efficient transfers you're taking some percentage hit per mile. Closer generation is generally going to be smarter, especially if you're running cables through what would be really viable offshore wind fields.
I totally agree that power lines have improved recently. That fiddles with the details, and doesn't change the fact that even if these advances pan out, there will be (very long) distances that you'll want to ship energy that will be more efficient with ships than power lines.
You're right to point out that tankers are phenomenally efficient, but that's _for oil_. Just as LNG is much more expensive to ship than oil, because of the increased handling complexity, any shipping of hydrogen is going to lose that advantage completely to electrification.[0]
> there will be (very long) distances that you'll want to ship energy
This is probably the real crux driving the difference in how we see this.
The main reason we have to ship hydrocarbons long distances is because those resources are so concentrated. Wind and solar aren't perfectly distributed, but they are so much more distributed that local generation would be much more efficient than transporting anything much beyond what current HVDC projects can easily handle.
So, sure, we're not going to stretch a cable for 12,000 miles. But we're also not going to build a solar farm in Saudi Arabia to generate hydrogen to ship to Canberra. We're just going to put a solar farm in the outback instead.
[0] "Relative costs of transporting electrical and chemical energy" by Saadi, Lewis, and MacFarland, studies this very question.
Even in that report, you could quibble with a lot of their assumptions that I think bias it against HVDC, project lifespans, ignoring loading and unloading costs for tankers, etc. But it's not a crazy starting place, and HVDC still beats hydrogen on $ per mile per Joule. My takeaway from it was that if we're stuck with a carbon economy, sure, we'll keep using tankers. If we're talking about going carbon neutral, the difficulties of working with hydrogen relative to oil and LNG will probably tip us back towards electrification and local generation, except in the most highly specialized of situations (fueling Antarctica or something).
The report was a good reminder why we have an oil-based economy though. It is so obnoxiously practical and well suited to everything we want to use it for. Ditching carbon will be hard.
The article you mention has no discussion of ammonia, just hydrogen and LOHC. That plus your mention of shipping energy into Canberra makes me wonder if we're actually communicating with each other at all.
Since ammonia and LOHCs face some overlapping constraints I don't expect an order of magnitude difference in cost. But you're right, it would have been more useful with an explicit comparison.
If you are seeing stuff that suggests ammonia will get very close to parity with oil, that's really fascinating, I hope it pans out that way. The IAE is more optimistic than I am about ammonia transport, while still listing some significant hurdles:
I think it's a good report, and you could read it to be more convinced of either of our positions.
Sorry we're talking past each other. You did actually change my mind a bit, if it's any consolation. Agree it's too hasty to say electrons are always better than atoms, though I'm still optimistic about more supergrids. My main remaining concern is just that, as you change your power mix away from oil to generate more ammonia, or electrolytic hydrogen, or whatever, the case for shipping fuel erodes significantly, because you can just move generation closer instead.
Sorry we couldn't get to ground on this one. Thanks for your points all the same.
Grrrr. It's efficiency is based on using a fuel cell. There seems to be a few ways around of storing Hydrogen in clever ways - this just adds to the list. But until we discover unobtainium that's as efficient as platinum in fuel cells but common and a fraction of the price, it's all a pipe dream.
Had they burnt it in an ICE, and come up with those figures then OK. As it is, when using technology that exists now it won't be 5 kg per 500km, it will 25 kg at best, and 500l of this material will be required.
Hydrogen storage may be useful in the future. But probably not for cars. Battery EVs are better environmentally (much lower carbon footprint and higher efficiency), have longer range and more power.
It’s too bad the story had to be written about car applications rather than the MOF itself.
I beg to differ. You still need an absolutely massive amount of raw material for batteries. This is it’s own environmental problem unrelated to climate change. Fuel cell cars can easily have 500km+ ranges and upwards of 900hp if you really wanted that much power. Not sure how you can argue this point at all.
This is good research for low-pressure hydrogen storage, but I think pursuing hydrogen powered cars is folly. It still has to be mined or generated, refined, and transported to filling stations, whereas with electric cars the transport and filling network is already in place. It's still a middleman to lose efficiency that electric cars don't have.
Hydrogen could be a win if we can get it into the tank in a couple minutes. Very few apartments or workplaces have EV chargers so far, and it's impractically slow to do anywhere you weren't planning to park for a long time. A Tesla Supercharger station would have to be 10x as big as a gas station to accommodate the general public stopping for a half hour each for a partial charge, assuming they would put up with the wait.
You could have made the same comment 6 years ago, and behold, lots more people drive EVs today than 6 years ago.
There's been a lot of progress in cajoling and requiring apartment complexes and workplaces to install chargers, and Tesla has a lot more superchargers (mostly in mall parking lots) than they used to have.
So it sure doesn't seem like there's any insurmountable problem involved that would cause us to stop promoting EVs.
Meanwhile, hydrogen fuel cells haven't fallen in price like Toyota predicted, and so their hydrogen car is both expensive and low performance. Not a winning combination, even if it fuels up in 5 minutes.
We bought a house recently, one of our requirements was "somewhere to plug in the Leaf", it wasn't hard, about half the places we found met that requirement (we didn't require actual power points to be in place - note at 240v a Leaf fast charge isn't required, it happily charges overnight during the cheap off-peak period)
I’d say you just aren’t paying attention to the gains being made in fuel cell technology. A lot of people on this website are really oblivious to this, so you’re not alone.
The 2021 Mirai using only 10 grams of platinum. Although they haven’t spoken much about pricing, it’s pretty obvious this is going to be a cost effective car to manufacture. Certainly, it’s going to be a lot cheaper to produce than a car with 600kg of batteries.
The upcoming BMW X5 Hydrogen is going to have 370 hp. I’d say that’s plenty.
Uh, OK. We're N years into the Hydrogen Revolution and the only problem is that people are ignorant?
It was the 2017 Mirai that was supposed to be powerful and cheap. Now it's 2021. The old model had 151 hp. The new one has... ? neither a price nor a performance?
The low end gas X5 has 335-456hp. So far the BEVs that have sold well have much higher performance than the minimum.
It's not a function of time but rather progress. Since there has been significant progress (mostly ignored by the tech community), the commonly used arguments against hydrogen are now wrong.
So we should be reasonably sure the new Mirai is going to be much faster than the first. It's also going to have around 400 miles of range and will be much bigger and more luxurious. We haven't heard about pricing yet, but from a production standpoint Toyota has talked extensively about how much cheaper it is to make.
It's not impossible, but the network is still far from "already in place". Wikipedia says US plug-in EV ownership is only 3.4%, and those drivers had better all own houses with attached garages.
OK, I guess it's a problem with no known solution, even though EV sales are climbing nicely.
Me, I've owned an EV for 6 years, and live in an apartment. 6 years ago the pessimistic estimate was that what has actually happened today is impossible.
Time is the solution. Gas stations weren't everwhere overnight. To this day they require a tanker fuel truck to deliver more inventory. On the other hand, the network for electricity is already in place. Distribution and refilling are "automated." EV needs a bit more time. The stars are there. They will alight soon enough.
when the last mile needs a couple hundred million charging points (with grid to supply them concurrently) and so far building them out has barely started. This is the entire reason I'm still burning gasoline for a couple of years; I can't rely on finding a charger at our next apartment.
Everyone's wants and needs are different. Some more fringe that others. This is part of traction and growth. Eventually, you'll be in the sweet spot.
p.s. Prediction: Post-pandemic, lock-down aside, look for Whole Foods to add charging stations. It's not a wait to recharge if you're being productive otherwise.
I'm guessing you don't live in urban California, where most grocery stores installed L2 chargers 5 years ago? They were intended for short-range EV charging, and most EVs aren't short range enough to find them useful. I rarely see anyone charging at the ones in Palo Alto. Some Tesla Superchargers are near grocery stores, that's a pretty nice combination. I do have one friend who hasn't bothered to install a home charger because she can use the supercharger next to her favorite grocery store.
Every HN thread mentioning EVs has at least one person concerned because they personally can't charge a car at home. It rarely leads to good discussion.
Investing in electrical infrastructure aligns with the way the world is going -- higher consumption (not only EVs but growth in general) + higher local generation (local PV)
I expect it will just happen anyway. Meanwhile hydrogen will require all new single-use infrastructure.
Hydrogen is anything but “single-use.” We will need it for long-haul trucking, large ships, trains, airplanes, construction and work equipment, farm equipment, etc. Not to mention solving grid intermittency, making steel, concrete, ammonia, providing industrial heat, etc.
If you think the problem through, the hydrogen infrastructure we need is going to dwarf the battery and electricity infrastructure. This is all before we consider hydrogen powered cars.
Why would trains need hydrogen? Almost all are electric. If they aren't in your region, why not convert it to electric? Large ships, why hydrogen? Seems again not a good solution.
Trains are diesel-electric. In practical terms, they're still internal combustion powered. Switching everything over to fuel cells is way simpler than setting up tens of thousands of miles of overhead power lines.
There's no path to powering a large ship with batteries. I'm not sure if you understand the physics behind it, but it pretty much has to be a hydrogen based fuel. Either liquid H2, or a derivative like methanol or ammonia.
It's a MOF (metal-organic framework). Basically a metal ion or metal cluster linked (nodes) together with organic molecules (linkers or struts). Some of them are even stable in aqueous solutions (like UiO-66). Typically, the linker-metal bond is via a carboxylic acid, and the metal node is something like... Zr, Ce, Hf, Ti, Fe, Cu, Co, Mn, Al, etc. etc. They've been the gold standard for gas sorption and hydrogen-car promises for at least 17 years.
The actual term MOF was apparently first used in 95[0].
While there are a lot of things that can affect the synthesis (metal concentration, metal precursor, metal:linker ratio, solvent choice, presence or absence of water, modulators, synthesis temperature), the synthesis of MOFs is usually about tuning what goes into the pot. Then its shake-n-bake and MOF comes out a day later (solvothermal method). So, it's an easy synthesis if you know what to load into your reaction vessel. While continuous synthesis is a harder, I think it's a lot more immediately scalable than porous aromatic frameworks (PAFs).
This work is combining some of the advantages of MOF (high specific surface area, regular structure, easy synthesis) with some of the advantages of PAFs (even higher specific surface area). You can see the linker they use on PDF page 5 of the supplementary online material[1]. The hexadentate structure is large and is reminiscent of PAFs like PAF-1[2], which are known for having very high specific surface area. This is because the aryl group has a high specific surface area. By making the linker very large and bulky, they're reducing the contribution of the metal nodes to the specific surface area by having a greater volume fraction of (lightweight) aromatic linker. However, while PAFs usually (always? I'm not a PAF person) have an SP3 carbon center (and thus a tetrahedral symmetry), this linker is kind of shaped like a paddle wheel with three paddles (or a trigonal prism, if you access the Science article and see Fig. 1). Thus, while PAFs are typically in a diamond-like net (dia [3]), this MOF is in a acs net[4].
Fun fact: Most MOFs are named after the research institution that found them first. This one is named NU-1500 for Northwestern University, where Farha is. The UiO-series are named after Universitet i Oslo, the HKUST series is named for Hong Kong University of Science and Technology, the MIL series is named for Material Insitute Lavoisier.
I'd like to know how it compares to existing solutions, the only thing I see in abstract is meeting/exceeding some US gov target. Can someone knowledgeable weigh in on this? How big of progress is this?
I wonder if this same principle could be used to store air for scuba tanks. It would be an improvement over existing compressed air tanks if the tank could be made smaller and lighter.
>Now, researchers believe they have developed an alternative method that would allow the storage of high volumes of hydrogen under much lower pressure.
They'll still be 100 reasons to favor battery EVs to renewable hydrogen fuel cells. Better storage does not increase its inferior well-to-wheel efficiency.
That’s really the only reason to favor BEVs over hydrogen. Everything else, from weight, cost (eventually), range, raw material requirements, are better with fuel cells.
This is a teeny tiny problem for a hydrogen cars. It doesn't really address the problem that fuel cells are ridiculously expensive, or that there's no filling network, or that there's no good way to fill them at home, or that fuel cells are themselves only 50% efficient typically.