Hacker News Reader

Comment by natmaka | Hacker News Reader

The connection is that "it will also have natural gas capacity" seems false to me as backup turbo-alternators can 'burn' hydrogen ( => no natural gas capacity).

> hydrogen > contributes less than a rounding error to global electricity generation

True, however it doesn't imply that it will remain irrelevant.

> unviable financially

For the time being, and less and less. Bloomberg NEF predicts that green hydrogen will cost approximately 1.2€/kg in 2050. Carbon taxes or oil prices may also play a role as nearly all hydrogen is now produced thanks to some fossil fuel.

> nuclear > is a genuinely low-carbon source of electricity

Green hydrogen could also be.

> prone to leakage

This is a major challenge for transportation-related usages, especially in small or not-intensively used vehicles. This isn't in the "gridpower backup" role, as mass and volume of storage isn't a major parameter.

View on HN

I see what you meant now but still see little scope for hydrogen to have a role in the energy sector.

One reason for my skepticism is that I've been hearing optimistic predictions around hydrogen as an energy store for decades at this stage (I'm old) and for a long time believed them but here we are, with little to show for it. In fact, at historical scales, hydrogen's significance as an energy store today is less than it was in the 19th century. As a result, I've adopted "I'll believe it when I see it" approach so I just ignore hydrogen predictions - particularly ones 25 years into the future.

But the main reason is simple physics. It simply has NONE of the physical attributes you'd want in a gas to be used to store energy. It's like if you picked all the attributes you WOULDN'T want in such a gas.

Storage and transport are incredibly expensive and technically difficult. Everything it comes into contact with needs special materials to avoid embrittlement. It's prone to leakage.

It has dreadful energy density. The worst.

It has potent green house gas effects when leaked into the atmosphere.

It's dangerous and highly explosive and burns with such high intensity (and invisibly) that it requires specialist fire-fighting equipment.

Roundtrip efficiency (electricity to H to electricity) is abysmal - a fraction of that of batteries.

In summary, hydrogen as energy store makes no sense to me. And it's completely hypothetical. If we are going to talk about hypothetical approaches to storing energy in the form of a gas, then green methane makes a lot more sense. Not that I'd advocate for either but I see some potential for green methane but none for hydrogen given its physical attributes.

> I've been hearing optimistic predictions around hydrogen

Fair point, same here (I was born in 1967), however fossil fuels are so effective and adequate as energy sources, as long as we ignored/neglected their dubious effect on the climate, that there was no real attempt to explore other ways.

> Storage and transport are incredibly expensive and technically difficult

For the "gridpower backup" application there is no transport needed, and storage doesn't have to be compact nor mobile (those are a major challenge for hydrogen in transportation).

> dreadful energy density

This is not a show-stopper for the "gridpower backup" application. For huge volumes or very long-term (not sure this will be necessary) it may be stored in salt caverns ( https://en.wikipedia.org/wiki/Hydrogen_storage#Underground_h... )

> potent green house gas effects > dangerous

Granted, however we are used to store huge volumes of dangerous materials, some gaseous at ambiant pressure/temp (methane...), even into salt caverns, albeit when we began to do so (in the 1950's) it was quite a challenge.

> Roundtrip efficiency (electricity to H to electricity) is abysmal

Various new ways to obtain H2 from electricity offer impressive yield in realistic conditions (check SOECs), and other advances are promising ( https://liten.cea.fr/cea-tech/liten/english/Pages/Strategic-... ).

> green methane makes a lot more sense

As does ammonia, in some contexts. There is no one-size-fits-all here!

Reply on news.ycombinator.com