At "low pressures" (5-30x normal sea level atmospheric pressures) H2 needs roughly 2.5meters cubed to store 1kg of H2.
Apparently it's "normally" stored at 350 to 700 bar (700x sea level air pressure). Compressing it that much requires a bunch of specialized equipment and a lot of energy.
It needs to be stored in complex pressure vessels at -160C or below[2]. I'd hate to have this stuff in big pipelines in a giant network, when utilities still can't quite do normal pressure natural gas correctly[3].
It leaks through just about everything, and lots of "normal" things that it leaks through it also destroys it while leaking through it[4].
A hydrogen economy would require trillions of dollars of infrastructure to work. A methane economy can just work -- it's basically what's already in use to move natural gas around.
So -- I can't point to an existing technology that'd be 100% ideal for a zero net pollution (overall, not just at the point of use) for a mega truck or similar big utility vehicle running a strip mining operation. But H2 really seems like a non-starter once you look at the details. I think maybe better batteries, hot-swapped batteries, hybrid methane generators plus batteries, etc, is a start, and it can be done today. I personally would take a 60% improvement now over a maybe 90% improvement later but probably never.
There's lots of carbon floating around; you can collect it from industrial processes (cement / steel making). You can pull it out of the air or water if you really do have enormous amounts of "spare" energy, which realistically, you probably don't.
At "low pressures" (5-30x normal sea level atmospheric pressures) H2 needs roughly 2.5meters cubed to store 1kg of H2.
Apparently it's "normally" stored at 350 to 700 bar (700x sea level air pressure). Compressing it that much requires a bunch of specialized equipment and a lot of energy.
It needs to be stored in complex pressure vessels at -160C or below[2]. I'd hate to have this stuff in big pipelines in a giant network, when utilities still can't quite do normal pressure natural gas correctly[3].
It leaks through just about everything, and lots of "normal" things that it leaks through it also destroys it while leaking through it[4].
A hydrogen economy would require trillions of dollars of infrastructure to work. A methane economy can just work -- it's basically what's already in use to move natural gas around.
So -- I can't point to an existing technology that'd be 100% ideal for a zero net pollution (overall, not just at the point of use) for a mega truck or similar big utility vehicle running a strip mining operation. But H2 really seems like a non-starter once you look at the details. I think maybe better batteries, hot-swapped batteries, hybrid methane generators plus batteries, etc, is a start, and it can be done today. I personally would take a 60% improvement now over a maybe 90% improvement later but probably never.
There's lots of carbon floating around; you can collect it from industrial processes (cement / steel making). You can pull it out of the air or water if you really do have enormous amounts of "spare" energy, which realistically, you probably don't.
[1]http://www.awoe.net/Hydrogen-Compression-General.html
[2]https://www.sciencedirect.com/topics/engineering/cryo-compre...
[3]https://en.wikipedia.org/wiki/Merrimack_Valley_gas_explosion...
[4]https://en.wikipedia.org/wiki/Hydrogen_embrittlement
[edited to add reference to gas explosions and formatting]