6 ms·

What really hits me here is the weight of the fuel cells, at only 31kg (+ container) for 400KM range. Compare that to battery cells which are usually >400kg.

What really hits me here is the weight of the fuel cells, at only 31kg (+ container) for 400KM range. Compare that to battery cells which are usually >400kg. Edit: There is ALSO a 73.2 kW battery.. geesh.

edhelas 4y ago
How much energy do you need to compress this H2 ?
- deleted 4y ago
  [deleted]
- kUdtiHaEX 4y ago
  Not nearly as much as required to produce batteries.
  - eis 4y ago
    Apples and oranges. You would need to compare energy needed to produce the tank and fuel cell to the production of batteries.
    - kUdtiHaEX 4y ago
      Sure but in that case please add energy costs for recycling the batteries bs recycling tanks for hydrogen. And I do not see how batteries can win in this race.
      - snovv_crash 4y ago
        Hydrogen embrittled metal isn't very recycling friendly.
  - msh 4y ago
    And how long is the lifetime? A battery lasts for many years. H2 is used more or less immediately.
- tmikaeld 4y ago
  Around 7% of the energy will be lost when refueling a 700-bar container (If i remember correctly)
  - HPsquared 4y ago
    How much of that is recoverable? With a heat engine on the compression side to reclaim the heat, and a turbine on the expansion side to reclaim the work.
- pbhjpbhj 4y ago
  A promising development is physical-chemical storage that doesn't require compression for storage, that seems to make hydrogen powered vehicles far more likely to win out over current battery-based EV technologies. One of the technologies metal organic frameworks (MOF) seems to have been creating some buzz recently. General overview: https://www.energy.gov/eere/fuelcells/materials-based-hydrogen-storage https://www.energy.gov/eere/fuelcells/materials-based-hydrog...
  - ZeroGravitas 4y ago
    Even with zero storage costs, hydrogen cars can't compete with batteries, since it's electricity -> battery -> electric motor vs electricity -> hydrogen -> battery -> electric motor and that extra step takes energy. It's only on longer distances that it begins to make sense as a tradeoff but even there it's not clear there's much room for it in the market.
    - pbhjpbhj 4y ago
      Surely with hydrogen it's a fuel cell (and relatively v. small battery for regenerative braking and such), not a battery like a BEV? And as the hydrogen, using a tech like MOF, would be cheaper to store, and easier to store longer term ... the extra energy expense seems a priori to remove a lot of e- waste and reliance on mining in developing nations. I'm not sure how the life-cycle overall energy usage compares, would be interested in reading a study of someone wants to link one. I'm hoping that hydrogen storage will become easy enough that we'll use that for large scale excesses like those from nation-size grids during excess production. So we can do seasonal shifting at scale.
      - ZeroGravitas 4y ago
        Hydrogen Fuel Cell is about 4x less efficient than BEV because you lose about half the initial energy making the hydrogen and half of that going back to electricity again. It's just very hard to come back from that if you have an alternative that uses the electricity directly. They're still better than conventional ICE (as long as the hydrogen is made from renewable energy) but just on energy alone BEVs are about 88% efficient, FCEVs 22% and ICE 18% efficient.
adrianN 4y ago
I read it as 31kg of hydrogen. You probably need quite a bit of steel around that and a fuel cell.
- hnov 4y ago
  I believe the outer shell is usually fiber reinforced.
CorrectHorseBat 4y ago
31kg of H2, the tanks themselves will be much heavier than that.
eis 4y ago
That is the weight of the hydrogen fuel. It does not include the weight of the tank nor the fuel cell so is not comparable to battery weight in a regular EV. The trucks also have 72kWh worth of batteries in them and it is not clear if a 400km range includes a fully charged battery pack at the start. Interestingly Hyundais page has slightly different specs for both fuel capacity as well as battery. https://trucknbus.hyundai.com/global/en/eco/hyundai-hydrogen-mobility https://trucknbus.hyundai.com/global/en/eco/hyundai-hydrogen...
goethes_kind 4y ago
Battery fanbois choose to ignore why batteries suck so much: they weigh too much, they take up a lot of space, and they take forever to recharge. They see hydrocarbon based fuels are dirty, but you cannot really beat that energy density.
- onethought 4y ago
  Not just dirty but also relatively finite (on earth). Hydrogen is generally manufactured from fossil fuels.
  - goethes_kind 4y ago
    So are batteries and the energy they are charged with. That is such a dishonest argument. Of course the intention is not to dig up hydrocarbons to then transform them into hydrogen to then later transform them back into hydrocarbons.
    - MichaelCollins 4y ago
      Even if you assume ample clean electrical energy as a given, breaking up hydrocarbons is still the easiest way to get hydrogen. Together, solar/wind/nuclear/hydro produce about a third of all the world's electrical generation. Despite this, only 4% of hydrogen production in 2020 used electrolysis; 95% was produced from fossil fuels.
      - erichocean 4y ago
        > Together, solar/wind/nuclear/hydro produce about a third of all the world's electrical generation. Including nuclear and hydro in the 1/3 is kind of deceptive since both sources are actively been phased out (c.f. Germany). Wind and solar generate just over 1/10 of global energy, although it's increasing every year.
        MichaelCollins 4y ago
        Deceptive? I'm comparing sources of hydrogen that don't produce CO2, to those that do. The supply of carbon neutral electrical power far surpasses the supply of carbon neutral hydrogen power. It's not even close. I don't know why you're bringing Germany specifically into this (misdirection? deception?) The overwhelming majority of hydrogen production comes from fossil fuels no matter what country you look at. If you replaced all the nuclear and hydro in the world with solar power, most hydrogen production would still be coming from hydrocarbons. Germany produces about 10% of their electrical energy with solar power, so do you think they produce 10% of their hydrogen with solar powered electrolysis? Hell no they don't. Electricity -> hydrogen sucks even if you have a 100% solar grid. "Green hydrogen" cannot compete with batteries. Hydrogen only looks kinda okay relative to batteries if you're getting the hydrogen cheap by breaking apart hydrocarbons instead of water (aka "gray hydrogen"), and even then it sucks and has gotten out competed.
jjk166 4y ago
For context, diesel would be about 70kg for the same range. Batteries have very poor specific energy.
danans 4y ago
> Edit: There is ALSO a 73.2 kW battery.. geesh All hydrogen fuel cell vehicles use small batteries to buffer charge to actually drive the electric motors because the fuel cell power output isn't high enough. 73kWH isn't huge for a large truck, equivalent to current small passenger EVs. For a vehicle whose fundamental purpose is to haul heavy freight, the excess weight imposed by batteries is uneconomical, which is a why fuel cells make sense - especially when the H2 is renewably generated.
- mtgx 4y ago

edhelas 4y ago

How much energy do you need to compress this H2 ?

deleted 4y ago
[deleted]
kUdtiHaEX 4y ago
Not nearly as much as required to produce batteries.
- eis 4y ago
  Apples and oranges. You would need to compare energy needed to produce the tank and fuel cell to the production of batteries.
  - kUdtiHaEX 4y ago
    Sure but in that case please add energy costs for recycling the batteries bs recycling tanks for hydrogen. And I do not see how batteries can win in this race.
    - snovv_crash 4y ago
      Hydrogen embrittled metal isn't very recycling friendly.
- msh 4y ago
  And how long is the lifetime? A battery lasts for many years. H2 is used more or less immediately.
tmikaeld 4y ago
Around 7% of the energy will be lost when refueling a 700-bar container (If i remember correctly)
- HPsquared 4y ago
  How much of that is recoverable? With a heat engine on the compression side to reclaim the heat, and a turbine on the expansion side to reclaim the work.
pbhjpbhj 4y ago
A promising development is physical-chemical storage that doesn't require compression for storage, that seems to make hydrogen powered vehicles far more likely to win out over current battery-based EV technologies. One of the technologies metal organic frameworks (MOF) seems to have been creating some buzz recently. General overview: https://www.energy.gov/eere/fuelcells/materials-based-hydrogen-storage https://www.energy.gov/eere/fuelcells/materials-based-hydrog...
- ZeroGravitas 4y ago
  Even with zero storage costs, hydrogen cars can't compete with batteries, since it's electricity -> battery -> electric motor vs electricity -> hydrogen -> battery -> electric motor and that extra step takes energy. It's only on longer distances that it begins to make sense as a tradeoff but even there it's not clear there's much room for it in the market.
  - pbhjpbhj 4y ago
    Surely with hydrogen it's a fuel cell (and relatively v. small battery for regenerative braking and such), not a battery like a BEV? And as the hydrogen, using a tech like MOF, would be cheaper to store, and easier to store longer term ... the extra energy expense seems a priori to remove a lot of e- waste and reliance on mining in developing nations. I'm not sure how the life-cycle overall energy usage compares, would be interested in reading a study of someone wants to link one. I'm hoping that hydrogen storage will become easy enough that we'll use that for large scale excesses like those from nation-size grids during excess production. So we can do seasonal shifting at scale.
    - ZeroGravitas 4y ago
      Hydrogen Fuel Cell is about 4x less efficient than BEV because you lose about half the initial energy making the hydrogen and half of that going back to electricity again. It's just very hard to come back from that if you have an alternative that uses the electricity directly. They're still better than conventional ICE (as long as the hydrogen is made from renewable energy) but just on energy alone BEVs are about 88% efficient, FCEVs 22% and ICE 18% efficient.

adrianN 4y ago

I read it as 31kg of hydrogen. You probably need quite a bit of steel around that and a fuel cell.

hnov 4y ago
I believe the outer shell is usually fiber reinforced.

CorrectHorseBat 4y ago

31kg of H2, the tanks themselves will be much heavier than that.

eis 4y ago

That is the weight of the hydrogen fuel. It does not include the weight of the tank nor the fuel cell so is not comparable to battery weight in a regular EV. The trucks also have 72kWh worth of batteries in them and it is not clear if a 400km range includes a fully charged battery pack at the start. Interestingly Hyundais page has slightly different specs for both fuel capacity as well as battery. https://trucknbus.hyundai.com/global/en/eco/hyundai-hydrogen-mobility https://trucknbus.hyundai.com/global/en/eco/hyundai-hydrogen...

goethes_kind 4y ago

Battery fanbois choose to ignore why batteries suck so much: they weigh too much, they take up a lot of space, and they take forever to recharge. They see hydrocarbon based fuels are dirty, but you cannot really beat that energy density.

onethought 4y ago
Not just dirty but also relatively finite (on earth). Hydrogen is generally manufactured from fossil fuels.
- goethes_kind 4y ago
  So are batteries and the energy they are charged with. That is such a dishonest argument. Of course the intention is not to dig up hydrocarbons to then transform them into hydrogen to then later transform them back into hydrocarbons.
  - MichaelCollins 4y ago
    Even if you assume ample clean electrical energy as a given, breaking up hydrocarbons is still the easiest way to get hydrogen. Together, solar/wind/nuclear/hydro produce about a third of all the world's electrical generation. Despite this, only 4% of hydrogen production in 2020 used electrolysis; 95% was produced from fossil fuels.
    - erichocean 4y ago
      > Together, solar/wind/nuclear/hydro produce about a third of all the world's electrical generation. Including nuclear and hydro in the 1/3 is kind of deceptive since both sources are actively been phased out (c.f. Germany). Wind and solar generate just over 1/10 of global energy, although it's increasing every year.
      - MichaelCollins 4y ago
        Deceptive? I'm comparing sources of hydrogen that don't produce CO2, to those that do. The supply of carbon neutral electrical power far surpasses the supply of carbon neutral hydrogen power. It's not even close. I don't know why you're bringing Germany specifically into this (misdirection? deception?) The overwhelming majority of hydrogen production comes from fossil fuels no matter what country you look at. If you replaced all the nuclear and hydro in the world with solar power, most hydrogen production would still be coming from hydrocarbons. Germany produces about 10% of their electrical energy with solar power, so do you think they produce 10% of their hydrogen with solar powered electrolysis? Hell no they don't. Electricity -> hydrogen sucks even if you have a 100% solar grid. "Green hydrogen" cannot compete with batteries. Hydrogen only looks kinda okay relative to batteries if you're getting the hydrogen cheap by breaking apart hydrocarbons instead of water (aka "gray hydrogen"), and even then it sucks and has gotten out competed.

jjk166 4y ago

For context, diesel would be about 70kg for the same range. Batteries have very poor specific energy.

danans 4y ago

> Edit: There is ALSO a 73.2 kW battery.. geesh All hydrogen fuel cell vehicles use small batteries to buffer charge to actually drive the electric motors because the fuel cell power output isn't high enough. 73kWH isn't huge for a large truck, equivalent to current small passenger EVs. For a vehicle whose fundamental purpose is to haul heavy freight, the excess weight imposed by batteries is uneconomical, which is a why fuel cells make sense - especially when the H2 is renewably generated.

mtgx 4y ago