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Hydrogen has the benefits of delayed time-of-use. For example, nuclear power continues to create energy at night, at 2am when there aren't many trains running.

Hydrogen has the benefits of delayed time-of-use. For example, nuclear power continues to create energy at night, at 2am when there aren't many trains running. In contrast, when an electric train pulls from the grid, it needs electricity immediately, no matter how loaded the grid is. Electric Trains running at 7pm (during the "Duck curve") will inevitably be powered by natural-gas peaker plants. --------- In contrast, Hydrogen electrolysis could continue into the night and be powered by "otherwise unused" 2am or 3am electricity from nuclear power. Even if the train was running at 7pm, the electricity comes from the most advantageous time throughout the day. That is to say: Hydrogen is a fuel, AND a battery, AND is compatible with electrification technologies thanks to the fuel cell.

Kayou 4y ago
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? Wouldn't it be more efficient than transporting the hydrogen by truck and transporting the hydrogen battery on every train?
- rightbyte 4y ago
  Yes. That would be a better idea.
  - morphle 4y ago
    but it would still be very much more expensive than just solar
    - dragontamer 4y ago
      Solar isn't even competing against Hydrogen. Hydrogen is a storage technology, not really an energy source. Hydrogen competes with Li-ion batteries. How many Li-ion batteries do you need to equal one 200-ton liquid H2 storage tank? At 120MJ per kg, 200-tons == 200,000 kg == 6GW-hrs of electricity. There's no Li-ion battery in the world that's anywhere close to that kind of storage capacity... and various researchers are aiming at 3000ton H2 storage tanks. Erase 50% or even 80% of the energy due to inefficiency / costs of cryogenics, and you still have a bigger energy storage tank from H2 than anything possible with Li-ion. And the future of H2 is looking like 10x capacities are reasonable over the next 10 years. ------- Whatever solar solution you were thinking, just do the same except instead of using big, expensive, heavy Li-ion batteries, replace the storage mechanism with H2 fuel cells.
      - nine_k 4y ago
        Higher energy density = higher danger of releasing it unintentionally. I totally understand why hydrogen is a great rocket fuel. You need this high energy content and the extreme lightness for high Isp. On land, I suppose, the energy density of 100 tons of hydrogen in one place is unnecessarily high. The fact that hydrogen has no odor, and its flame is entirely infrared, invisible, does not help. By the same token, I think that lithium batteries have excessive energy density for large-scale land applications, like buffer storage for solar / wind power. Even a lead-acid battery, with all its environmental downsides, weight, etc is at least not a major fire hazard. I suppose that large-scale electricity storage will take off when cheaper and safer, while less dense, alternatives to lithium batteries are commercialized. As a power source for a car, a lithium battery at least is not cryogenic. OTOH on the scale of a train this may already be not a big problem. Same possibly for an oceangoing ship, but it would be terrible to start losing fuel and power if a bad storm damages the cryogenic system. An ideal (fantastic) system could use methane and turn it into carbon, only oxidizing the hydrogen. Sadly, similar reactions only work so far with much more complex molecules.
        _hypx 4y ago
        Lithium batteries are extremely flammable. Worse, fires are extreme hard to extinguish. For trains this would be a truly huge fire. Converting methane into hydrogen is known as steam reformation. We can easily due this, but we don't want to because it is a fossil fuel.
        ben_w 4y ago
        > The fact that hydrogen has no odor, and its flame is entirely infrared, invisible, does not help. I thought it was UV? (Which, if anything, is even worse).
- dragontamer 4y ago
  > 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-storage-problem-could-be-hydrogen.html 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 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/ 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).
morphle 4y ago
Only consider the Levelised cost of Energy (LCOE) over the lifetime of systems, like solar+ electrical cables and night-time batteries versus solar generating hydrogen, storing plus transport plus burning or fuel cells in new locomotives. If you look at LCOE over lifetime, solar photovoltaics always wins over wind, hydro and certainly over hydrogen and nuclear. Lowest cost wins. Hydrogen made from solar electricity is around 40% efficient, so it is more than 2.5 times more expensive (expensive storage and transport) than just solar and overhead electric cable. Cheaper still because you can put solar panels along the train tracks so land use is almost free. You would have much less losses if you convert solar panel 40-60V directly into high voltage the train use.
- vitiral 4y ago
  ... if the train only ran in the daytime, right?
- dragontamer 4y ago
  > and night-time batteries Why can't those night-time batteries be Hydrogen? And instead of running electrical wires, why don't we pump that Hydrogen into a pipeline that goes to the train station? That way, our energy transport uses cheap steel-and-concrete to move our energy around, rather than expensive copper and transistors. And instead of electrifying 3000 miles of track, why won't the Locomotive engine be a fuel cell that converts the H2 back into electricity on board?
  - morphle 4y ago
    Because Hydrogen is too expensive. If you calculate the LCOE, you'll find that using wind at night is cheaper than hydrogen. Maybe certain batteries storing solar can beat wind at cost? My point remains, don't guess "why not use my favorite X" but calculate and simulate all alternative systems and the the lowest cost of energy ofve lifetime of systems is the winner you actually build.
    - dragontamer 4y ago
      A pipeline and a steel drum, even built to withstand 700Bar of pressure, is cheaper than 1MW circuits that you propose lining thousands of miles of rail with. Transistors, transformers, and electric wires use an incredible amount of copper.
deleted 4y ago
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Kayou 4y ago

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? Wouldn't it be more efficient than transporting the hydrogen by truck and transporting the hydrogen battery on every train?

rightbyte 4y ago
Yes. That would be a better idea.
- morphle 4y ago
  but it would still be very much more expensive than just solar
  - dragontamer 4y ago
    Solar isn't even competing against Hydrogen. Hydrogen is a storage technology, not really an energy source. Hydrogen competes with Li-ion batteries. How many Li-ion batteries do you need to equal one 200-ton liquid H2 storage tank? At 120MJ per kg, 200-tons == 200,000 kg == 6GW-hrs of electricity. There's no Li-ion battery in the world that's anywhere close to that kind of storage capacity... and various researchers are aiming at 3000ton H2 storage tanks. Erase 50% or even 80% of the energy due to inefficiency / costs of cryogenics, and you still have a bigger energy storage tank from H2 than anything possible with Li-ion. And the future of H2 is looking like 10x capacities are reasonable over the next 10 years. ------- Whatever solar solution you were thinking, just do the same except instead of using big, expensive, heavy Li-ion batteries, replace the storage mechanism with H2 fuel cells.
    - nine_k 4y ago
      Higher energy density = higher danger of releasing it unintentionally. I totally understand why hydrogen is a great rocket fuel. You need this high energy content and the extreme lightness for high Isp. On land, I suppose, the energy density of 100 tons of hydrogen in one place is unnecessarily high. The fact that hydrogen has no odor, and its flame is entirely infrared, invisible, does not help. By the same token, I think that lithium batteries have excessive energy density for large-scale land applications, like buffer storage for solar / wind power. Even a lead-acid battery, with all its environmental downsides, weight, etc is at least not a major fire hazard. I suppose that large-scale electricity storage will take off when cheaper and safer, while less dense, alternatives to lithium batteries are commercialized. As a power source for a car, a lithium battery at least is not cryogenic. OTOH on the scale of a train this may already be not a big problem. Same possibly for an oceangoing ship, but it would be terrible to start losing fuel and power if a bad storm damages the cryogenic system. An ideal (fantastic) system could use methane and turn it into carbon, only oxidizing the hydrogen. Sadly, similar reactions only work so far with much more complex molecules.
      - _hypx 4y ago
        Lithium batteries are extremely flammable. Worse, fires are extreme hard to extinguish. For trains this would be a truly huge fire. Converting methane into hydrogen is known as steam reformation. We can easily due this, but we don't want to because it is a fossil fuel.
      - ben_w 4y ago
        > The fact that hydrogen has no odor, and its flame is entirely infrared, invisible, does not help. I thought it was UV? (Which, if anything, is even worse).
dragontamer 4y ago
> 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-storage-problem-could-be-hydrogen.html 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 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/ 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).

morphle 4y ago

Only consider the Levelised cost of Energy (LCOE) over the lifetime of systems, like solar+ electrical cables and night-time batteries versus solar generating hydrogen, storing plus transport plus burning or fuel cells in new locomotives. If you look at LCOE over lifetime, solar photovoltaics always wins over wind, hydro and certainly over hydrogen and nuclear. Lowest cost wins. Hydrogen made from solar electricity is around 40% efficient, so it is more than 2.5 times more expensive (expensive storage and transport) than just solar and overhead electric cable. Cheaper still because you can put solar panels along the train tracks so land use is almost free. You would have much less losses if you convert solar panel 40-60V directly into high voltage the train use.

vitiral 4y ago
... if the train only ran in the daytime, right?
dragontamer 4y ago
> and night-time batteries Why can't those night-time batteries be Hydrogen? And instead of running electrical wires, why don't we pump that Hydrogen into a pipeline that goes to the train station? That way, our energy transport uses cheap steel-and-concrete to move our energy around, rather than expensive copper and transistors. And instead of electrifying 3000 miles of track, why won't the Locomotive engine be a fuel cell that converts the H2 back into electricity on board?
- morphle 4y ago
  Because Hydrogen is too expensive. If you calculate the LCOE, you'll find that using wind at night is cheaper than hydrogen. Maybe certain batteries storing solar can beat wind at cost? My point remains, don't guess "why not use my favorite X" but calculate and simulate all alternative systems and the the lowest cost of energy ofve lifetime of systems is the winner you actually build.
  - dragontamer 4y ago
    A pipeline and a steel drum, even built to withstand 700Bar of pressure, is cheaper than 1MW circuits that you propose lining thousands of miles of rail with. Transistors, transformers, and electric wires use an incredible amount of copper.

deleted 4y ago

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