[dirk94018]

Hydrogen has been the future as long as I have been paying attention to electric cars. There are many problems with it, including Hydrogen is the smallest molecule. It leaks through seals, embrittles metals, and has terrible energy density by volume. You either compress it to 700 bar (heavy tanks), liquefy it at -253°C (energy-intensive), or store it in metal hydrides (heavy, slow release). Solid state batteries are much more interesting. They extend EV range to 600-1000 miles and enable 10-minute charging. If they work at scale, they kill hydrogen for cars, trucks, and probably short-haul aviation too.

[defrost]

The path of most interest to many is Renewables -> bulk hydrogen as storage -> electricity grid.

The bulk storage method of interest is dissolved salt caverns: https://news.ycombinator.com/item?id=47160599

[idiotsecant]

Bulk hydrogen makes a lot less sense than pumping water up a hill. We have thousands and thousands of sites throughout the country that would be great for pumped storage and require absolutely no advanced technology. They are buildable today.

[rob74]

I guess that with "throughout the country" you mean the US? There, building gigantic new pumped storage systems might work, e.g. somewhere on a mesa in a desert with few people living nearby (OTOH you need some source of water for pumped storage too, so a desert location is not really ideal), but in more populated locations (i.e. Europe) such a project would face opposition and interminable delays caused by all the NIMBYs living next to it.

Besides that: pumped storage is good for regulating short-term fluctuations (between day and night), not so sure about storing surplus renewable energy produced in summer to use it during winter, as the article proposes?

[defrost]

Location, location, location - there are many sites globally suitable for geological bulk hydrogen storage; the UK has had the Tesside site operational until recently since the early 1970s.

They were built 50 years ago. (Slightly before today).

Pumped hydrogen at Walpole is a great functional little project that eases the grid edge brown out problem. ( https://news.ycombinator.com/item?id=45332157 )

Scaling that up to the energy storage potential of the right geological structures of the sizes needed to power cities and run heavy industrial isn't as economically clearcut as you may assume.

[defrost]

> Pumped hydrogen

== Pumped hydroelectric / pumped water <doh>

[rfv6723]

Solid state batteries are overhyped because their production complexity makes them a pricing nightmare for the average consumer. Sodium ion batteries are the practical choice for short distance transport because they are affordable and charge incredibly fast.

When it comes to long distance shipping or aviation, the energy density of liquid fuel is simply too hard to beat. Fossil fuels will stay dominant for decades, likely evolving into carbon captured or bio derived alternatives rather than being replaced by batteries.

[nerdsniper]

Compressed hydrogen and cryogenic liquefaction also present explosive/BLEVE risks. Metal-hydride is probably the only reasonably safe-ish option. Other issues (like hydrogen embrittlement, leaking, slower flow-rate) are all very real challenges, but 'solvable'. Solving all of them at a price that consumers/businesses can stomach is quite debatable.

Batteries are just too good nowadays to expect hydrogen to receive the level of R&D and infrastructure investment to become at all competitive.

[_carbyau_]

> enable 10-minute charging.

I have a problem with the current physics of this. A car requires a LOT of energy to run. The electrical requirements "at the pump" are going to be pretty hefty for 10 minute charging.

Unless:

1. Reduce capacity requirements. IE Cars evolve smaller and smaller until they are practically aerodynamically efficient go-karts. A trend opposite of current affairs....

2. Charge for longer timeframes but swap in less than 10 minutes. IE standardise and replace batteries as needed.

I suspect that the "10 minute recharge" meme will be obviated by ridiculous ranges allowing us to then charge while sleeping instead.

[xbmcuser]

2-3 min battery replacement is already a thing in China for trucks. The largest manufacture CATL is also pushing for safety and compatibility standards so all trucks can use all truck batteries in future. And for charging they are building charging stations with batteries that are charged slowly but can charge cars fast. The electricity revolution is just picking up pace

[mikestorrent]

Trucks are a far cry from cars. There's a lot more space and specialized service facilities and maintenance procedures are the norm. Drivers are expected to understand far more about their vehicles.

[xbmcuser]

I don't understand what you mean Nio the car manufacturer is already doing 100k+ battery swaps a day for passenger cars. I mentioned ev trucks as some mentioned that hydrogen would be easier / cheaper for trucks which I think is wrong as using explosions to move object won't be as cheap or maintenance free as using electricity to move magnets/motors.

[mikestorrent]

I've gone and watched a video on this now and am impressed, it is a lot further along than I knew about.

Consider this as it scales up, though - I can get electricity from anywhere for my car, from a 120V socket in front of a building that a nice owner lets me borrow for an hour, to a 600VDC superfast charger. I can get gasoline anywhere. Heck, there are even hydrogen stations around here now.

I just don't see this kind of thing being scalable to anything other than small urban areas, which are exactly the place they're not needed, because you can charge a car with 300-400km battery range once a week or less and be fine in the city. Where I need my battery swap is more likely to be while I'm on a road trip going for distance. How could I be confident a full battery that's compatible with my car is going to be available for me, and that all the automation to replace it will be in perfect shape, and that the bottom of my car hasn't rusted to the point where this doesn't work anymore?

[xbmcuser]

Actually battery swaps and needing fast charging are for city car owners for rest of the people that own houses they mostly don't need fast charging. They can install solar and can easily charge at home. Most private cars run for less than 2 hours a day. And are parked somewhere most of day I think need for fast charging is mostly about non ev owners not realising they do not need to do things the way they used to with gas cars. Battery swapping is more useful for commercial vehicles that are constantly running

[mikestorrent]

I like the idea of swappable batteries in theory, but in reality... well... that's a lot of logistics and a lot of potential for things to go wrong. Consider the swappable propane tank market, for instance; it's clear that returning cans need refurbishment and testing before you can give them back out to people. This implies it probably can't be just done on-site at a gas station.

They also weigh an absolute ton, so specialized lift equipment is needed; they take up space and will be very difficult to move around. So, are we expecting to stock a huge pile of batteries somewhere with an automatic loader/unloader that can handle multiple people at once with a quick turnover rate that can put away a 2000 pound battery? It's just too much infra, compared to a charging station...

And then there's the matter of the vehicle design; chassis rigidity is important and batteries, being a huge weight, need to be positioned properly with enough load bearing structure around them to support this. I'm imagining a hydraulic lift raising a 2000 pound battery up into my car; some massive brace needs to be attached below it to hold it up. Talk about difficult to get right; we've got harsh conditions like road salt and rust to deal with, and we have to make a fully automatable fastening device that can work at a random gas station with any brand of car... yikes.

You're actually much closer to the idea with the reduce-capacity idea. I had a Ford Focus Electric a while ago that had about 80km of range on a good day. This was more than enough for 90% of my driving; my old SUV handled the rest. Net carbon savings were huge; pity it was totaled in an accident or I'd have kept it going. Even at almost 10 years old it still kept a charge no problem and was a delight to drive compared to a normal Focus. My current EV has far more range but feels heavy and ponderous despite nearly 500 HP.

[RandallBrown]

Doesn't Nio have a few thousand battery swapping stations in China?

[shellfishgene]

They just announced a while ago that they performed their 100 millionth battery swap, and just now "Nio's 3,750 battery swap stations delivered 2,073,500 battery swap services between February 10-23" (Chinese new year). Seems to work fine.

[mikestorrent]

Another commenter pointed that out, it's impressive, but when one imagines trying to do that kind of thing in North America where we can't even build new train tracks it seems somewhat infeasible

[vardump]

Very much simplified, a 10 minute charge would mean 6C charging throughout the curve. 100 kWh battery would thus require 600 kW on average. Right now the most powerful MCS chargers deliver 1440 kW.

So not impossible, as long as the battery can handle the current. It's obvious that charging technology is not going to be the bottleneck.

(A real battery would probably have a charging curve that slows down towards the end, so more than 6C would be required in realistic conditions.)

[idontwantthis]

It's always been clear to me that Hydrogen is not the future, because the car companies that made hydrogen cars never tried to build a hydrogen fuel distribution system.

The main reason EVs are a thing is that Tesla built the supercharger network. The fact that Honda or Toyota didn't do that for Hydrogen is the reason it has not been a serious fuel alternative. And they probably didn't do that because they always knew the economics would never work out and were never serious about pursuing it.

[toomuchtodo]

Electric heavy duty trucks are already here, with existing battery technology.

> In 2020, nearly all new trucks in China ran on diesel. By the first half of 2025, battery-powered trucks accounted for 22% of new heavy truck sales, up from 9.2% in the same period in 2024, according to Commercial Vehicle World, a Beijing-based trucking data provider. The British research firm BMI forecasts electric trucks will reach nearly 46% of new sales this year and 60% next year.

> The share of electrics in new truck sales, from 8% in 2024 to 28% by August 2025, has more than tripled as prices have fallen. Electric trucks outsold LNG-powered vehicles in China for five consecutive months this year, according to Commercial Vehicle World.

> While electric trucks are two to three times more expensive than diesel ones and cost roughly 18% more than LNG trucks, their higher energy efficiency and lower costs can save owners an estimated 10% to 26% over the vehicle’s lifetime, according to research by Chinese scientists.

https://www.ap.org/news-highlights/spotlights/2025/chinas-di...

https://electrek.co/2026/01/24/hybrid-and-electric-semi-truc...

https://www.electrive.com/2026/01/23/year-end-surge-electric...

[tjmc]

Looking forward to seeing solid state batteries for aviation, but the scary part is that they get heavier when they discharge as oxygen from the air turns into solid oxide.

[AnthonyMouse]

Isn't that good for aviation? Makes it relatively less expensive to carry reserve energy you don't expect to use, don't have to pay the weight cost during takeoff when weight costs the most energy because you just charged the battery and once you're at cruising speed more weight is just neutral momentum.

Probably the least convenient thing would be if you had to land and take off again somewhere without recharging.

[jMyles]

> Probably the least convenient thing would be if you had to land and take off again somewhere without recharging.

...or... go around?

[AnthonyMouse]

Except you started with 1500 miles of charge for a 200 mile flight because "fully charged" weighs less.

If you're up there waiting for a long time you don't have to fly in a tight circle at a high speed.

[tjmc]

The issue is maximum take off weight. Presumably the discharged battery weight would be the one you use in the pre-flight MTOW calculations, because the worse case scenario is one where you're landing an almost discharged battery and have to go around.

[jMyles]

Yes, this was exactly my thought; maybe I needed to state it more clearly.

[svnt]

My favorite part is that high pressure hydrogen leaks can auto-ignite in air.

http://www.icders.org/ICDERS2007/abstracts/ICDERS2007-0255.p...

[adonovan]

> Hydrogen is the smallest molecule. It leaks through seals, embrittles metals, ...

Second smallest, after monatomic Helium molecules (which have similar problems of storage, embrittlement, and leakage).