[nickbauman]

Hyrodgen can play a huge role in energy storage in a green economy. Creating and storing hydrogen for later use, like when a solar farm is idle at night; as it likely has a surplus during the day, is a common problem with all energy grids.

[Symmetry]

Of course it can play a role in energy storage in a green economy. But the piece outlines a number of disadvantages it has versus other forms of energy storage. An electrolysis-fuel cell round trip is only around 33% efficient and the capital costs are pretty high. If you want grid storage batteries, potential energy storage, or all sorts of things work better. If you need a fuel you can synthesize from the air for a vehicle that can't use batteries then ethanol or methane are better bets from a storage perspective.

[jsjohnst]

Gasoline powered internal combustion engines average around 20% efficiency, cutting edge new stuff still doesn’t really break 40%. Need to keep that in mind! Yes, gasoline itself is very energy dense, but that doesn’t mean we efficiently use it in automobiles.

[Gibbon1]

Amusingly lithium is also really energy dense too. The difficulty is it's only 2-3% of the battery by weight. Upside of that is there is a lot of room for improvement. Not that it's easy low hanging fruit though.

For transport hydrogen suffers a lot of the same issues as lithium. The storage systems are all heavy. Compare with an empty gasoline tank you can lift with one hand.

[Symmetry]

In terms of energy efficiency in powering moving vehicles then yes, hydrogen is as energy efficient as anything else. That's why I complained about it's energy density rather than its efficiency in that context. In terms of grid storage batteries are ~99% efficient and pump storage is 75% efficient.

[semi-extrinsic]

I think the big boost for hydrogen this time around will be production from natural gas with carbon storage. It allows us to decouple how quickly we wind down natural gas production from how quickly we decarbonize, and that is a killer solution.

[Symmetry]

Ok, if we can produce hydrogen from natural gas without letting the carbon out that would actually be interesting.

[semi-extrinsic]

Production from natural gas using steam methane reforming plus water gas shift reaction is how 95% of the worlds hydrogen is made. After these processes, one must anyways separate out the CO2, to make the H2 usable. This is done at industrial scale, hundreds of billions of standard cubic metres every year. Mostly the CO2 is just released, but increasingly it is caputred and stored.

The technology is easily scalable to meet demand, in fact it has to scale far less than how much battery production has to scale from current levels.

I'm convinced it's not a question of if, but a question of when this becomes a major thing. We're at the point where we need all the technological and societal mechanisms we can muster.

[macspoofing]

>Mostly the CO2 is just released, but increasingly it is caputred and stored

Define 'increasingly'

And after you get you H2, what are you going to do with it? You're not going to use it to power vehicles, that's for sure.

[VBprogrammer]

I haven't heard anyone seriously suggesting hydrogen as a surplus storage mechanism. Do you have any examples of this, examples of pilot plants or whatever? Most I've seen are discussing using molten salt to directly store heat from during the day which can be used to power turbines over night.

[nradov]

Why would anyone choose to use hydrogen for storing surplus power when other storage mechanisms are so much more cost effective?

[coldtea]

>Hyrodgen can play a huge role in energy storage in a green economy.

Which is already addressed in the article: hydrogen is best as a storage medium, but even as that it's not-green and very mediocre storage.