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Comment by flavius29663 | Hacker News Reader

There are ways to work around those limitations, basically removing the "very small and very reactive" part of hydrogen. You can bind it with Nitrogen to gen ammonia - which is till very dangerous, but much easier to contain or work with.

The problem with H2, ammonia, biofuels and other synthetic fuels is not that they have some limitations, it's that they are not accepted by the green energy dogma. Some green energy activists would like to see the gas stations go away, for example, and that is not going to happen if you keep needing to go somewhere to re-fuel, with any fuel.

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The problem isn't "dogma," it's inefficiency. Throwing energy away is counterproductive, and Energy-to-Hydrogen-to-Energy throws away lots of it.

If there were no alternative long-term storage plans this might be acceptable, but that's simply not the case.

If you're using hydrogen to smelt steel or make ammonia fertilizer, then there's no energy loss (beyond what's needed to decarbonize petrochemicals anyway). The article aptly refers to these as "no regrets" uses.

Gas stations (ie ground vehicles) are fighting a losing battle. BEVs will eat the sector. They're simply so much less expensive [than hydrogen]: for the vehicles themselves, for the infrastructure, and then of course for the wasteful energy use in operation.

> Throwing energy away is counterproductive, and Energy-to-Hydrogen-to-Energy throws away lots of it.

The current process needs 55kWh of electricity to produce 15kWh of electricity on the other end. Not very efficient at all.

Look at how much energy is on the other end of the oil flow: 20% efficiency and still the ICE car is king, without subsidies, EVs would go nowhere. The hydrogen back and forth is still better than that.

Talking about efficiency is a losing battle, people don't care about that, they care about total cost, safety and convenience.

> Talking about efficiency is a losing battle, people don't care about that, they care about total cost, safety and convenience.

Without subsidies it is ICE that would go away overnight on two of those three factors and then the third shortly after the market catches up to the overnight shift. EVs already have lower total cost and higher safety (than carrying around a tank of explosives and actively igniting those explosives during travel). ICE looks more convenient with current refueling infrastructure, but if ICE subsidies disappeared and demand plummeted we'd see how fast ICE range anxiety returns when companies quickly en masse decide to not sell such a low margin loss leader. (I do mean "returns", we know from history that ICE vehicles were the original range anxiety and EVs were the reliably ranged household cars until enough gas stations existed. AAA was in part founded because of ICE range anxiety.)

(H2 cannot compete with EVs on any of these three. Total cost is higher. H2 tanks can dangerously explode, even if fuel cells are not themselves at least using a burning process like ICE. H2 refuelling seems convenient if you discount the fact that there's no general, ubiquitous H2 refuelling infrastructure and likely never will be, especially with how badly H2 leaks in all attempts at long distance shipping and long term storage.)

ICE vehicles conquered the world with abysmal efficiencies, they were around 10-15% when they already ruled the roads and the world. That is after we drill for oil, ship it, refine it, distribute it. Even today, manufacturers boast about engines with 40% efficiency in ideal conditions, which still translates to a meager 20-30% in real world driving.

Looking at efficiency alone is not enough.

> They're simply so much less expensive

Not yet they aren't. The upfront cost of an EV still makes it more expensive than an ICE vehicle. Also, they batteries are guaranteed to degrade, so the used market has very bad prices for EVs. At some point, they will probably be less expensive for most automobiles, but hydrogen can still play a part in trucking, trains, planes, boats and specialty operations.

Only about 64% of oil is used for transportation [1] and out of that, only about 50% for automobiles and light trucks [2] (even though for light trucks, motorcycles and other applications, EVs are not going to win probably). So BEVs could replace about 30% of all oil usage. The rest of 70% is up for grabs, so why not pursue hydrogen investment as a possible alternative?

https://www.eia.gov/energyexplained/oil-and-petroleum-produc...

https://www.eia.gov/energyexplained/use-of-energy/transporta...

> more expensive than an ICE

The (relevant) comparison was H2 versus BEVs — ie comparing decarbonized solutions apples-to-apples. I have edited to make that more clear.

> why not pursue hydrogen investment as a possible alternative?

Because hydrogen, for all its marketing, doesn't solve the problems people have with BEVs. Better BEVs do.

I see a variety of BEV motorcycles and light trucks available. The same can't be said for hydrogen.

> Because hydrogen, for all its marketing, doesn't actually solve the problems people have with BEVs. Better BEVs do.

I guess it depends on the definition of "people". If you mean private automobile owners, then I agree that batteries will eat hydrogen's lunch. For everything else(70% of oil use), it's an open question. In the future, you might even see a migration of H2 technology from large applications to small automobiles, like we've seen with diesel engines.

> I guess it depends on the definition of "people". If you mean private automobile owners

I'm just following your lead. You were the one who brought up "gas stations."

>For everything else(70% of oil use), it's an open question

Not really. Road use is ~50% .[1] It's all going BEV, like it or not.

Agriculture is another 10%. Ditto.

The technology improvement curves speak for themselves. ICE and H2 have both plateaued near their theoretical limits.

I intentionally said "ground vehicles," not private cars.

[1] https://www.statista.com/statistics/307194/top-oil-consuming...

Even for non-ground vehicles my understanding is that the future of H2 is very murky: small aircraft have proven some efficiencies with battery electric that H2 cannot match, other than possibly as a generator to top up a large battery and if the large batteries themselves hit certain densities (which seems increasingly likely as BEV car production picks up and economies of scale start to take effect) it won't be worth the weight for an H2 generator and liquid H2 tanks. I've heard at least one scientist flat out state that carrying liquid H2 is about the dumbest efficiency possibility for air travel because if you are going to carry all that H2 anyway at least carry it as a gas and get free ballast from it. The only efficient H2 air travel is exactly the one we've known about for centuries: dirigibles. But we know that's a PR minefield in current popular culture to even suggest. (Which yes, we probably should have more dirigibles for other efficient air travel options.)

If battery densities end up meeting the needs of airplanes they meet the needs of ships easily enough. Plus, there's interesting new research on wind power for ships, which I find is a lovely irony to see ships return to wind power after all these years (though it may look quite different than the classic age of sail with primary propulsion still being electric turboprops).

Neither solution is really decarbonized. It is also wrong to say only carbon leaves an ecological imprint. Recycling of batteries will be a huge logistical challenge or leave a high ecological impact itself.

Still, either a vehicle is more or less drives continuously or batteries will be the better alternative. But that is only for that sector.

Fossil fuel transport is fundamentally carbonized. BEVs are currently about 50% better, but at least it's feasible to achieve full decarbonization.

Recycling of batteries is very efficient at >95%[1], and will only get better with time.

As for addressing only one sector, welcome to the world of high-complexity problems. Climate change is a "1000 cuts" type, not a "magic bullet" type.

[1] https://techcrunch.com/2021/09/14/jb-straubels-redwood-mater...

>Fossil fuel transport is fundamentally carbonized.

Exactly, and I wish I understood why people thought this was a smart point.

EVs are a link in the chain that in and of themselves have no fundamental energy dependence on fossil fuels. They have an incidental reliance on fossil fuels to the extent that electricity is generated from fossil fuels. But they're a piece of the infrastructure puzzle that in and of themselves is fully solved and compatible with decarbonized infrastructure. I would like to think that one goal in advancing public understanding of EVS should be educating people to the point that this particular talking point never gets used ever again.

>Looking at efficiency alone is not enough.

In general I would say I actually agree with this. It can be perfectly feasible to use an energy source that's terribly inefficient in some intuitive sense, but as long as it's economical to do so, poses no environmental harm, and you're getting significantly more energy out than you're putting in, you can be as inefficient as you want.

Now that said, I don't think that this kind of general truism is terribly responsive in this particular case, because it's nevertheless going to be true that inefficiency, and whatever sense you construe it, can indeed be a deal breaker and I think that's what GP is intending to communicate with respect to h2, biofuels, etc.

>ICE vehicles conquered the world with abysmal efficiencies, they were around 10-15% when they already ruled the roads and the world.

Fossil fuel comes out of the ground with the energy already in it, hydrogen doesn't exist in a free form and the energy must be put into it coming from somewhere else.

Most hydrogen now comes from natural gas at maybe 75-80% efficiency through reforming, then it must be compressed, then it must be burned at similar efficiencies to fossil fuel or used in a fuel cell with slightly better efficiency than ICE.

It's way worse in efficiency than fossil fuels, you could just use the natural gas directly in a combustion engine and be way ahead. Solar/wind/nuclear to electrolysis is even worse, just charge a battery.

Hydrogen is a energy storage mechanism like a battery not a source of energy like fossil fuel.

Look at well to wheel efficiency BEV are far ahead of hydrogen.

Ulf Bossel got it right ~16 years ago. No significant change since then, other than steady improvement in BEVs.

https://phys.org/news/2006-12-hydrogen-economy-doesnt.amp

Battery technology has utterly stagnated. There has been basically no changes in energy density in over a decade. All "progress" has been in the form of reduced cost, but even that has ended.

PS: Please don't post some Bloomberg article about this. They are wrong and did not correctly reference the state of battery technology back in 2010.

Isn't the whole point of cheap and plentiful renewable energy that inefficiencies in processes like this are irrelevant?

Why would long-term storage matter if wind and solar can produce so much energy that we cannot feasibly consume it all? What other long-term energy storage plans are there right now?

I would not write off fuel stations just yet. There may well be a future where some renewable fuel powers vehicles.

Cost would be an obvious factor. An inefficient electricity derivative fuel is always going to be more expensive than charging a battery directly from all that cheap/plentiful renewable electricity eliminating the "middle fuel". Especially when vehicle usage curves have a beautiful inverse to electricity demand curves and vehicles are generally parked for hours when electricity rates are at their very cheapest.

>Isn't the whole point of cheap and plentiful renewable energy that inefficiencies in processes like this are irrelevant?

No.

You're thinking of "too cheap to meter," which never came to pass, and (as it turns out) was just a marketing line.

>What other long-term energy storage plans are there right now?

https://news.ycombinator.com/item?id=34429623

There was a great article a few days ago about "factories as batteries" (pointing out that aluminum smelting is uneconomic but hydrogen works) but sadly I can't find it.

> Throwing energy away is counterproductive, and Energy-to-Hydrogen-to-Energy throws away lots of it.

Energy to plants to biofuels throws away nearly all the energy. More than all of it, by some accountings.

What are the alternatives for those use cases in which batteries are infeasible?

Pumped hydro (water) is about 81% efficient and easy enough to build with centuries of experience at this point.

There's also battery systems outside of Lithium Ion formulations which have other use cases. Thermal batteries are an interesting alternative in some use cases, particularly where fast access to heat in addition to electricy is handy (such as in collaboration with building HVAC and water heaters).

But also in general as we keep finding new density scales in the Lithium Ion formulations (and as we have hope to potentially discover even more formulations beside that) the number of use cases where batteries are infeasible keeps shrinking.

You'll never hear me defend biofuels.

The alternatives are mostly

* better batteries

* heat pumps to replace oil burners

* methane or ammonia for the remaining uses (eg trans-oceanic); globally shipping and aviation together account for only 8% of petroleum use

With a universal carbon tax everything would automatically self-organize into the most efficient solution, but of course we can't do that.

Off-road land use probably accounts for another few percent. It's hard to imagine heavy forestry, farming, and earthmoving equipment being powered by batteries.

Why not?

It seems like the real problem is a lack of imagination.

Are there some challenges? Of course. Are they insoluble? I can't see why they would be.

How about binding with Carbon and getting methane (CH4)?

that's exactly what I meant by "other synthetic fuels", but I was refraining from using the explicit words, because of the stigma, and I didn't want to derail the discussion.

At that point, why not just separate the hydrogen from all the methane we seemingly produce?

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