| > In that case what prevents us from building energy storage facilities that produce hydrogen at night and release the electricity back into the grid during the day? That's literally the plan? https://www.nrel.gov/news/program/2020/answer-to-energy-stor... Hydrogen is a newer technology than Li-ion. But yeah, its more than capable of these things. We just gotta build out pipelines and facilities to handle it. But no. To deliver MWs of electricity to trains requires using a ton of copper on all rail-lines, as well as advanced transistors to switch that electricity around. Hydrogen storage of electricity is a good idea and is being developed, but there are innate benefits to the fuel-methodology for applications like trains. In particular, a pipeline will likely transmit more "energy" at cheaper costs than a bundle of copper wires. Steel and concrete pipelines are just cheaper. So instead of building expensive copper wires + expensive transistors to switch electricity all around the place, why not build pipelines? > Wouldn't it be more efficient than transporting the hydrogen by truck and transporting the hydrogen battery on every train? Well, first off, the most efficient form of transporting Hydrogen would be a pipeline. But lets say we're dealing with a remote area so a truck is necessary. 1kg of Hydrogen has 120MJ of power, or 0.033 MW-hrs of electricity. A singular kilogram. https://www.energy.gov/eere/fuelcells/hydrogen-tube-trailers These trailers can store 900kg of Hydrogen. Or in other words, 30 Megawatt-hours of Hydrogen based electricity. Larger vehicles, like trains, can likely afford to carry larger containers, possibly even cryogenic liquid-hydrogen that is even more compact. https://demaco-cryogenics.com/blog/liquid-hydrogen-storage/ Current storage tanks from NASA can hold 270 tons of liquid Hydrogen, with plans to scale to 3000 tons of liquid hydrogen storage. That's 3000000 kg, or 100 Gigawatt-hours of energy storage per tank. -------- So yeah, the amount of H2 energy storage available far exceeds what is possible with Li-ion technology. Pipelines will be more efficient at moving Gigajoules / dozens of MW-hours at cheap costs. Trucks and trains can carry the fuel wherever they need to go. Energy storage / Hydrogen batteries will scale to far higher capacities than Li-ion could ever dream of. -------- Hydrogen is an incredibly light fuel. Its difficulty in transportation is __volume__ rather than its weight. Storage technologies, such as higher pressure (700-bar or higher), and liquid cryogenics are needed for H2 storage to be effective. These technologies are just becoming possible today. So only now can we dream of what liquid-hydrogen storage tanks can offer us. Literally 100GW-hrs of energy per liquid-hydrogen tank is feasible (while *current* prototypes from NASA are holding 9GW-hrs of energy storage). |
For a locomotive of a train, the volume of storage is a much more important limitation than the mass.
Moreover, after adding the mass of the fuel containers, it is likely that diesel fuel has also a greater energy per mass than hydrogen.
Hydrocarbon fuel can also be transported by pipelines.
So none of these arguments show any advantage of hydrogen versus the traditional diesel fuel.