It’s pretty clear that if we want fuel cell vehicles to happen we need two things - cheap hydrogen production (should I say extraction) and a nationwide infrastructure to deliver the fuel. The latter could be quickly solved, at least partially, using underground cavernous systems.
Caves filled with gas? Yes, pretty much any salt cavern or cave could double as a huge low-pressure storage tank according to a Sandia National Laboratories study. Storage above ground requires thick-walled 70 MPa tanks which don’t come cheap, so why not use an already available container created by Mother Nature?
Other than that, underground natural gas is already available for us to extract, so why couldn’t we reverse the process? Just find a big hole underground, make sure it’s airtight and fill it up with hydrogen.
Sounds easy, but in fact several studies must be performed in order to determine whether H2 reacts with other underground elements in different conditions. So far, the safest way is to use salt caverns, since it’s already known to hold in the gas pretty efficiently.
But salt formations are limited. There are none of them in the Pacific Northwest, a large part of the East Coast and the South, except for the Gulf Coast area. And reusing oil or other gas reservoirs and aquifers could leak hydrogen or contaminate it.
More than that, the “cavern recycling” can’t be done more than twice per year because it will affect the integrity of the rock formation and then you end up with sinkholes all over the place.
Other than that, underground natural gas is already available for us to extract, so why couldn’t we reverse the process? Just find a big hole underground, make sure it’s airtight and fill it up with hydrogen.
Not that easy, though
Sounds easy, but in fact several studies must be performed in order to determine whether H2 reacts with other underground elements in different conditions. So far, the safest way is to use salt caverns, since it’s already known to hold in the gas pretty efficiently.
But salt formations are limited. There are none of them in the Pacific Northwest, a large part of the East Coast and the South, except for the Gulf Coast area. And reusing oil or other gas reservoirs and aquifers could leak hydrogen or contaminate it.
More than that, the “cavern recycling” can’t be done more than twice per year because it will affect the integrity of the rock formation and then you end up with sinkholes all over the place.