If the goal is reducing CO2 emissions, then electricity will be used to break H2 from water. Currently most H2 is extracted from natural gas, which produces CO2 as a by-product. That is, H2 needs to be used as a chemical energy storage mechanism for low-carbon energy sources such as solar, wind, or (ick) nuclear.
Problem with this is that the round trip efficiency of electricity to H2 and back is around 30%. If you use the H2 in a combustion system then you might get 35-40% efficiency. LiION batteries are around 90%.
So once you solve the materials handling problems with H2 you are still left with a very expensive energy storage mechanism.
Of course, Lithium is a limited resource so we are going to need more storage mechanisms anyway, but pronouncing H2 as the future is misleading at best.
If the goal is reducing CO2 emissions, then electricity will be used to break H2 from water. Currently most H2 is extracted from natural gas, which produces CO2 as a by-product. That is, H2 needs to be used as a chemical energy storage mechanism for low-carbon energy sources such as solar, wind, or (ick) nuclear.
Problem with this is that the round trip efficiency of electricity to H2 and back is around 30%. If you use the H2 in a combustion system then you might get 35-40% efficiency. LiION batteries are around 90%.
So once you solve the materials handling problems with H2 you are still left with a very expensive energy storage mechanism.
Of course, Lithium is a limited resource so we are going to need more storage mechanisms anyway, but pronouncing H2 as the future is misleading at best.