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Comment by iconosynclast | Hacker News Reader

Hydrogen tech is a bit of an odd one to me since people rarely talk about the one good thing about it that might offset the otherwise just straight bad performance, you can store it for a long time! So in a world with truly massive renewable energy surplus during peak hours/days/months maybe hydrogen vehicles will make sense as a way of making use of this very inefficient but shelf stable form of storage. Until then I really don't see why people are getting excited about something that is a lot worse than battery electric in a lot of ways

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Hydrogen is notorious for it's ability to leak out of containers.

I doubt it's a great choice for long term energy storage.

This is false. h2 storage is a solved problem, people store, transport, and use h2 all the time.

true, but its not a particular efficient way to store it.

We'll get there. its early days

It's just a matter of scale. make your tank 4 times as big and the surface area for leakage only grows by a factor of 2. also there is already a natural gas grid that can take a lot of hydrogen without modification. Again this really only ever makes sense if you have an absurd energy surplus as a sort of last resort way to use energy that would otherwise go unused. In terms of actually being a desirable power system it seems like a complete nightmare to deal with unless you need to go really far out on the gravimetric energy density front with very low power density all while having a fraction of the efficiency of battery electric

I think your maths is off. For the same shape, surface area = volume ^ (2/3)

ah yes sorry got mixed up a bit there. a doubling in linear size leads to a quadrupling in surface area and an 8 fold increase in volume and then I somehow got confused from there m) nevertheless increasing size improves the situation

How does that improve the situation? One spark and it all goes boom. It’s not the relative size of the leaks to the volume of storage that matters, it’s the fact that even a small leak will go boom very easily.

Nah, in this context they are talking about hydrogen having so small molecules that it escapes from all containers you put it in. Increasing size of container decreases relative leak per volume (due to previously explained math).

Problems of the booming nature is a different topic.

Like most technologies, there are upsides and downsides. There is no need for everything in the world to be powered the same way, use what makes sense in each context.

For long distance heavy trucking, batteries are both very large and heavy. Hydrogen can offer an alternative there.

For air travel, batteries are very very heavy. Hydrogen is as far as I can google comparable with gasoline on that front, so an attractive proposition there as well.

Hydrogen fits into several different markets really well. And those opportunities taken together may well outweigh the limitations. Being able to exchange one form of energy for another is useful. Having lots of potential customers is beneficial. That is why I am excited about Hydrogen. The ecosystem is the most important thing and gives a critical mass. Its a big potential ecosystem...

* It can use spare renewable energy.

* It can be made with spare nuclear energy.

* It can be an input for large scale industrial processes like fertilizer production.

* It can be stored in old gas fields.

* It could be blended with natural gas and burned.

* It is a promising airline fuel

* It fits in well with existing oil infrastructure.

* It may be a fuel for vehicles and trains.

And many of these elements could exist within a small area. An oil refinery, chemical works, offshore windfarm, a few modular reactors, gas fields, natural gas exports, rail line, airfield. All within 50km and all potential suppliers and customers.

Although I am a bit uneasy about blue hydrogen!

Blue Hydrogen seems to have mostly died for economic reasons, Gray Hydrogen sadly is still being produced, though perhaps not for much longer. Blue hydrogen was mostly used as a 'jedi hand wave' to keep the Gray Hydrogen going.

Also, we really need to switch from saying "It can use spare renewable energy" to "the renewable energy built to power it can, in times of need, be directed to the grid instead, replacing peaker plants".

Same thing essentially but just 10/90 vs 90/10 on how much is used for the new thing, and how much goes to the grid for traditional uses.

To put this in perspective this is exactly what is needed for some use cases. I live in Singapore. We are a small island nation with zero natural resources. Currently our energy mix almost exclusively dominated by fossil fuels. The move away from fossil fuels is right now impractical as we don't have the necessary land space for solar and we dont receive enough wind to justify wind power. There are no mountains for hydroelectric power. We also have a massive energy footprint thanks to air-conditioning and industry. We don't have many alternatives other than to either (1) import green energy or (2) use nuclear.

(1) poses defense and logistic problem. We become victims to the whims of our neighbours (politicians in our neighbouring country have more than once threatened to cut our water supply). While, we do import water from malaysia, we can also be fully self sufficient should the need arise thanks to desalination and rain water cachement. As a small nation we have a requirement to defend ourselves. Petrol is very convenient as we have massive reserves that should last us a year should we need to go into siege batteries on the other hand don't. Thus a hydrogen economy is a massive game changer for us.

(2) is something we may explore. But as a land scarce island with no prior nuclear technology, we would need to develop new technology from scratch. It could easily be decades before a sufficiently large yield and safe reactor becomes available. Hydrogen on the other hand has a shorter run way.

Hydrogen vehicles are interesting (especially for things like public transport where battery capacity can be an issue - some cities have started looking at hydrogen buses for longer routes for example) but it is potentially pretty good as a potential grid level storage technology as well, even if cars largely become electric.

The thing is that the vehicles really aren't interesting at all unless you already have an energy surplus that makes the fuel cheap. unless you have that all you have is a vehicle that burns an expensive and or non renewable fuel (most hydrogen right now doesn't come from electrolysis) while getting just ok range and with the included headache of carting around a 700bar storage system and dubious ecological benefits over bad old hydrocarbons

We do have an energy surplus, we're just currently wasting a ridiculous amount of it for no particularly good reason.

Take the gas burned in homes for heating, burn it in power plants to generate electricity, power much more efficient heat pumps. We're already saving money and energy. Some countries figured this out in the 1970s.

Simultaneously, build out cheap renewables, to burn less gas for electricity production.

Same story for vehicles, take that oil/gasoline, burn it in power plants, use it to charge much more efficient EVs.

Hydrogen then can replace fossil fuels in other areas, e.g. fertilizers. (Again, put that now unused gas into electricity plants).

And so on, a virtuous cycle that takes you all the way to net zero and beyond.

As intermittent 'renewables' gain traction, 'green hydrogen' will more and more be available: https://en.wikipedia.org/wiki/Green_hydrogen

In my area there are a lot of electric city buses in use. AFAIK battery capacity isn't really an issue - they just charge them at the depot and then they're good for a day of use. Regional buses still tend to be natural gas-powered, though.

JCB is working on hydrogen-powered heavy/plant machinery to replace the existing diesel models. Batteries don’t last long enough for a day of work.

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