4 ms·

> The minimum theoretical energy to liquefy hydrogen from ambient (300 K, 1.01 bar) conditions is 3.3 kWh/kg LH2 or 3.9 kWh/kg LH2 with conversion to para-LH2 (

by _hypx 3y ago

> The minimum theoretical energy to liquefy hydrogen from ambient (300 K, 1.01 bar) conditions is 3.3 kWh/kg LH2 or 3.9 kWh/kg LH2 with conversion to para-LH2 (which is standard practice) [1]. https://www.hydrogen.energy.gov/pdfs/9013_energy_requirements_for_hydrogen_gas_compression.pdf https://www.hydrogen.energy.gov/pdfs/9013_energy_requirement... It is not guaranteed to be 30%. And you're entirely basing your argument on the idea that batteries will get radically more advanced, while hydrogen technology will not. What happens when Toyota makes a Corolla powered by hydrogen at the same level of cost and the fuel is basically free (made from excess green energy)? Will BEVs really have much of a future in that scenario?

_aavaa_ 3y ago
That's the theoretical limit and it's still ~10%. It's not guaranteed to be 30% no, but that's what they are now. > Actual liquefaction energy requirements are substantially higher, typically 10-13 kWh/kg LH2, depending on the size of the liquefaction operation [5,6]. > What happens when Toyota makes a Corolla powered by hydrogen at the same level of cost Pigs will fly. Toyota currently sells the Mirai, and it costs more than a model 3. The Mirai uses ~3x more electricity at the source to drive the same amount (assuming very optimistic efficiencies) and costs ~5x more to drive per mile. So I ask you, who will buy the Mirai instead of a model 3? The answer, based on sales data, is not many people. Because the Mirai is not even better for the environment unless you mange to source pure green energy hydrogen. So how will Toyota sell enough to bring down the cost of production? How long with it take for the hydrogen network to expand outside of california? A decade? And when that's happened, how will you convince the BEV drivers to sell their 10th gen BEV for a 3rd gen Hydrogen car? > and the fuel is basically free That is an absurd thing to claim. - Green electricity is not free since there's a Capex associated with it. - wind/solar does not suffer negative electricity rates in the same way that coal/gas/nuclear since they can be turned off on a whim. They do not have to generate excess energy if they don't want to. - Creating hydrogen from water is not free since there is expensive Capex associated with electrolyzers and other equipment required. - Combine the above 3 together and you'll find the idea of running your electrolyzers intermittenly for only a few hours when there's excess energy to be a laughable proposition from an economic point of view. - Compressing, storing, and transporting hydrogen is not free For reference, hydrogen from methane in the US currently sells for ~1.5$/kg. The idea that green hydrogren will get cheaper than that, much less free, is laughable.
- _hypx 3y ago
  10% is pretty what the losses of long distance HVDC will be. You are at the point of diminishing returns in terms of efficiency at that point. Not to mention that this is recoverable energy. Liquid hydrogen is literally cryogenic energy storage. You can easily find methods of shrinking losses ever further. Considering Toyota is literally making a hydrogen powered Corolla to go racing, your claim about cost is pure Ludditism. It time for you to stop living in the past. Hydrogen cars will be cheaper than BEVs to build and likely no more expensive to run. Perhaps its time you ask yourself a simple question: Once all of the facilities have been built, what is the margin cost of further production? It is in fact basically zero. This is for both wind and solar, but also anything made exclusively from it like green hydrogen. In fact, hydrogen could be the cheapest of them all, since it is not limited by the problems of intermittency and long-duration storage. As a result, it is a matter of when, not if you'll see hydrogen for $1.5/kg. And eventually even less than that. PS: Your post is just pure anti-progress. Imagine being so offended by the idea of advancements in green energy. So many of your type are just brainwashed BEV fanatics. It's pure short-sightedness.
  - _aavaa_ 3y ago
    I hope I don’t have to describe the chasm that exists between a 10% real loss in the whole of a process, versus a theoretic minimal loss of one step in a process. It is not anti-progress to point out obviously impossible things. > will be cheaper than BEVs to build and likely no more expensive to run. Please explain to the luddites in the room how it will cost the same. How it could ever cost the same. Both would start with electricity. The BEV would charge directly on that. The hydrogen car would require an electrolyzer, cleaning of the gas, compressing it, transmission, distribution, refueling stations, then a fuel cell. Each step along the way being costly and not 100% efficient. Hint: you can’t. Even if you hook up a perfect fuel cell to a perfect electrolyzer, for each kW you put into the electrolyzer you’ll be getting less than 1 kW from the fuel cell. Except the marginal costs is not zero. The marginal cost of the next kg of hydrogen is not zero. Electricity is not free, and each kg of hydrogen requires the same amount of electricity as the previous. Toyota making one car for their racing circuit is very different from them making it cheaply and people buying it on mass. Again, real operating costs of the vehicle they sell on the market today are 5x higher the BEVs, so why would anyone buy it? The only way you’ll reach green hydrogen for less 1.5$/kg is if you have an army of volunteers working on donated equipment for >0.02$/kWh. There are few of any places that even have electricity that cheap. It is not me that’s living in the past, it’s the hydrogen hype that has come back for its third crack at things. On the hope that maybe this time around thermodynamics will be different.
Schroedingersat 3y ago
The mirai has worse range, has less power, is heavier, has less internal space, is bigger, requires more mining if rare minerals for fuel cells, lasts fewer miles before replacing the storage/fuel cell system, refuelling for daily use is much more cumbersome and it costs ten times as much to fuel as current gen EVs. The supposed overwhelming advantage results in saving 20 minutes on a 1000km trip (if nobody else used the hydrogen station before you, otherwise fuelling times are the same). With current state of the art batteries being put into next model cars that last bit goes away too. In what possible world do hydrogen passenger cars have a future?

by _hypx 3y ago

_aavaa_ 3y ago

That's the theoretical limit and it's still ~10%. It's not guaranteed to be 30% no, but that's what they are now. > Actual liquefaction energy requirements are substantially higher, typically 10-13 kWh/kg LH2, depending on the size of the liquefaction operation [5,6]. > What happens when Toyota makes a Corolla powered by hydrogen at the same level of cost Pigs will fly. Toyota currently sells the Mirai, and it costs more than a model 3. The Mirai uses ~3x more electricity at the source to drive the same amount (assuming very optimistic efficiencies) and costs ~5x more to drive per mile. So I ask you, who will buy the Mirai instead of a model 3? The answer, based on sales data, is not many people. Because the Mirai is not even better for the environment unless you mange to source pure green energy hydrogen. So how will Toyota sell enough to bring down the cost of production? How long with it take for the hydrogen network to expand outside of california? A decade? And when that's happened, how will you convince the BEV drivers to sell their 10th gen BEV for a 3rd gen Hydrogen car? > and the fuel is basically free That is an absurd thing to claim. - Green electricity is not free since there's a Capex associated with it. - wind/solar does not suffer negative electricity rates in the same way that coal/gas/nuclear since they can be turned off on a whim. They do not have to generate excess energy if they don't want to. - Creating hydrogen from water is not free since there is expensive Capex associated with electrolyzers and other equipment required. - Combine the above 3 together and you'll find the idea of running your electrolyzers intermittenly for only a few hours when there's excess energy to be a laughable proposition from an economic point of view. - Compressing, storing, and transporting hydrogen is not free For reference, hydrogen from methane in the US currently sells for ~1.5$/kg. The idea that green hydrogren will get cheaper than that, much less free, is laughable.

_hypx 3y ago
10% is pretty what the losses of long distance HVDC will be. You are at the point of diminishing returns in terms of efficiency at that point. Not to mention that this is recoverable energy. Liquid hydrogen is literally cryogenic energy storage. You can easily find methods of shrinking losses ever further. Considering Toyota is literally making a hydrogen powered Corolla to go racing, your claim about cost is pure Ludditism. It time for you to stop living in the past. Hydrogen cars will be cheaper than BEVs to build and likely no more expensive to run. Perhaps its time you ask yourself a simple question: Once all of the facilities have been built, what is the margin cost of further production? It is in fact basically zero. This is for both wind and solar, but also anything made exclusively from it like green hydrogen. In fact, hydrogen could be the cheapest of them all, since it is not limited by the problems of intermittency and long-duration storage. As a result, it is a matter of when, not if you'll see hydrogen for $1.5/kg. And eventually even less than that. PS: Your post is just pure anti-progress. Imagine being so offended by the idea of advancements in green energy. So many of your type are just brainwashed BEV fanatics. It's pure short-sightedness.
- _aavaa_ 3y ago
  I hope I don’t have to describe the chasm that exists between a 10% real loss in the whole of a process, versus a theoretic minimal loss of one step in a process. It is not anti-progress to point out obviously impossible things. > will be cheaper than BEVs to build and likely no more expensive to run. Please explain to the luddites in the room how it will cost the same. How it could ever cost the same. Both would start with electricity. The BEV would charge directly on that. The hydrogen car would require an electrolyzer, cleaning of the gas, compressing it, transmission, distribution, refueling stations, then a fuel cell. Each step along the way being costly and not 100% efficient. Hint: you can’t. Even if you hook up a perfect fuel cell to a perfect electrolyzer, for each kW you put into the electrolyzer you’ll be getting less than 1 kW from the fuel cell. Except the marginal costs is not zero. The marginal cost of the next kg of hydrogen is not zero. Electricity is not free, and each kg of hydrogen requires the same amount of electricity as the previous. Toyota making one car for their racing circuit is very different from them making it cheaply and people buying it on mass. Again, real operating costs of the vehicle they sell on the market today are 5x higher the BEVs, so why would anyone buy it? The only way you’ll reach green hydrogen for less 1.5$/kg is if you have an army of volunteers working on donated equipment for >0.02$/kWh. There are few of any places that even have electricity that cheap. It is not me that’s living in the past, it’s the hydrogen hype that has come back for its third crack at things. On the hope that maybe this time around thermodynamics will be different.

Schroedingersat 3y ago

The mirai has worse range, has less power, is heavier, has less internal space, is bigger, requires more mining if rare minerals for fuel cells, lasts fewer miles before replacing the storage/fuel cell system, refuelling for daily use is much more cumbersome and it costs ten times as much to fuel as current gen EVs. The supposed overwhelming advantage results in saving 20 minutes on a 1000km trip (if nobody else used the hydrogen station before you, otherwise fuelling times are the same). With current state of the art batteries being put into next model cars that last bit goes away too. In what possible world do hydrogen passenger cars have a future?