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Hydrogen fuel is still a fossil fuel byproduct right? I’m not sure what the point of this is. It sure doesn’t seem like a green technology at this point.

onychomys 5y ago
Presumably it'll eventually be made by splitting water using electricity from renewable sources.
- batmenace 5y ago
  There are already early stage projects in France (and I assume other places as well) where Siemens Gamesa is using prototype turbines that does exactly this at an offshore wind farm
- SigmundA 5y ago
  Splitting water with electricity then recombining in the fuel cell back to electricity is extremely inefficient compared to just charging a battery with eletricity.
  - jandrese 5y ago
    It may make sense in cases where batteries aren't practical like ocean going container ships. There was a time a couple of decades ago when it might have made sense for cars when battery power wasn't good enough but that time has passed.
sandworm101 5y ago
It is, but it doesn't have to be. It is possible to make H2 from H20 and sunlight. At the moment there is little market for such "green" hydrogen but the hope is that hydrogen-based transportation will create that market. Imho I cannot afford to be a market leaders in this field. Until H2 is available everywhere, including at remote locations during Canadian winters, I'll have to stick to gas stations. (I have yet to see any electric car that can handle -50*c.)
- londons_explore 5y ago
  Handling very low temperatures isn't very hard if the car is designed with that in mind. It would simply have a small heater and insulation around the battery. A 3 inch thick layer of insulation around the battery should keep the heating power to 10 watts or so to keep the battery at -10*c. A 70kwh battery will last 7000 hours supplying 10 watts, or about a year. Longer if it isn't -50 every day.
- bdamm 5y ago
  While technically true, the conversion is inefficient. It takes a lot of power to extract H2 from H2O. You could just use that power directly. The problem with electrics in -50 is keeping them plugged in when not in use. -50 is very extreme though, you’re talking far north or Edmonton.
  - darksaints 5y ago
    The conversion using current SOEC technology isn't particularly inefficient. 88% efficient when using LHV values, 105% efficient when using HHV. http://www.helmeth.eu/index.php/technologies/high-temperature-electrolysis-cell-soec http://www.helmeth.eu/index.php/technologies/high-temperatur...
    - labcomputer 5y ago
      That analysis ignores the heat used to raise the reactant (water) temperature to 800C. On its face, the claim doesn't make much sense anyway. If you could convert water to 2 H2 + O2 at zero energy cost, you could make a perpetual motion machine by taking advantage of the exothermic reaction 2 H2 + O2 -> 2 H2O.
      - darksaints 5y ago
        That's the difference between LHV and HHV. It is possible to exceed 100% efficiency when using HHV because it is an inherently more conservative convention for energy content due to practical concerns. LHV, by contrast, is bounded by the laws of physics.
exitb 5y ago
It has a similar relationship to fossil fuels as electric cars.
- bdamm 5y ago
  Operating electric cars on coal generation produces more miles driven for the same carbon emissions than gasoline does.
- epistasis 5y ago
  Sort of, on some qualitative descriptions. But on the quantitative level they are quite different, enough to change the entire quality of the relationship to carbon. The cheapest source of electrical power are renewables, and for more than a decade renewables have been at cost parity. Additionally, electrical vehicles are the perfect complement to the weakness of renewables: intermittency. In contrast, the most optimistic estimates I have seen say that we are at least a decade from electrolyzed hydrogen that is as cheap as carbon-spewing current steam methane reformation. And in the interim, hydrogen boosters are pushing a nonexistent large-scale carbon capture and sequestration of steam methane reformation, something that doesn't exist on an industrial scale, with several failed projects over the past decade. So I would say that hydrogen cars today are like EVs in the mid 90s. The tech chain has a long ways to go.
hannob 5y ago
It's not a fossil fuel byproduct. It's a fossil fuel product. You take natural gas, split it in a process called steam reforming, you get hydrogen and CO2 emissions. Green hydrogen only exists in very small quantities these days and for many years to come it'll be needed to first replace existing natural gas based hydrogen and to decarbonize industries like steel. There's basically a consensus among energy experts these days that hydrogen in cars is a dead end.
boringg 5y ago
3 main sources. 1- Natural Gas 2- Renewable Natural Gas (capping waste emissions from waste water treatment or municipal solid waste and coverting to Hydrogen). Net negative CO2 but smaller supply 3- Electrolysis (electricity + water). Source of electricity determines the cleanliness of the H2. Still requires water which is not ideal (especially in california)

onychomys 5y ago

Presumably it'll eventually be made by splitting water using electricity from renewable sources.

batmenace 5y ago
There are already early stage projects in France (and I assume other places as well) where Siemens Gamesa is using prototype turbines that does exactly this at an offshore wind farm
SigmundA 5y ago
Splitting water with electricity then recombining in the fuel cell back to electricity is extremely inefficient compared to just charging a battery with eletricity.
- jandrese 5y ago
  It may make sense in cases where batteries aren't practical like ocean going container ships. There was a time a couple of decades ago when it might have made sense for cars when battery power wasn't good enough but that time has passed.

sandworm101 5y ago

It is, but it doesn't have to be. It is possible to make H2 from H20 and sunlight. At the moment there is little market for such "green" hydrogen but the hope is that hydrogen-based transportation will create that market. Imho I cannot afford to be a market leaders in this field. Until H2 is available everywhere, including at remote locations during Canadian winters, I'll have to stick to gas stations. (I have yet to see any electric car that can handle -50*c.)

londons_explore 5y ago
Handling very low temperatures isn't very hard if the car is designed with that in mind. It would simply have a small heater and insulation around the battery. A 3 inch thick layer of insulation around the battery should keep the heating power to 10 watts or so to keep the battery at -10*c. A 70kwh battery will last 7000 hours supplying 10 watts, or about a year. Longer if it isn't -50 every day.
bdamm 5y ago
While technically true, the conversion is inefficient. It takes a lot of power to extract H2 from H2O. You could just use that power directly. The problem with electrics in -50 is keeping them plugged in when not in use. -50 is very extreme though, you’re talking far north or Edmonton.
- darksaints 5y ago
  The conversion using current SOEC technology isn't particularly inefficient. 88% efficient when using LHV values, 105% efficient when using HHV. http://www.helmeth.eu/index.php/technologies/high-temperature-electrolysis-cell-soec http://www.helmeth.eu/index.php/technologies/high-temperatur...
  - labcomputer 5y ago
    That analysis ignores the heat used to raise the reactant (water) temperature to 800C. On its face, the claim doesn't make much sense anyway. If you could convert water to 2 H2 + O2 at zero energy cost, you could make a perpetual motion machine by taking advantage of the exothermic reaction 2 H2 + O2 -> 2 H2O.
    - darksaints 5y ago
      That's the difference between LHV and HHV. It is possible to exceed 100% efficiency when using HHV because it is an inherently more conservative convention for energy content due to practical concerns. LHV, by contrast, is bounded by the laws of physics.

exitb 5y ago

It has a similar relationship to fossil fuels as electric cars.

bdamm 5y ago
Operating electric cars on coal generation produces more miles driven for the same carbon emissions than gasoline does.
epistasis 5y ago
Sort of, on some qualitative descriptions. But on the quantitative level they are quite different, enough to change the entire quality of the relationship to carbon. The cheapest source of electrical power are renewables, and for more than a decade renewables have been at cost parity. Additionally, electrical vehicles are the perfect complement to the weakness of renewables: intermittency. In contrast, the most optimistic estimates I have seen say that we are at least a decade from electrolyzed hydrogen that is as cheap as carbon-spewing current steam methane reformation. And in the interim, hydrogen boosters are pushing a nonexistent large-scale carbon capture and sequestration of steam methane reformation, something that doesn't exist on an industrial scale, with several failed projects over the past decade. So I would say that hydrogen cars today are like EVs in the mid 90s. The tech chain has a long ways to go.

hannob 5y ago

It's not a fossil fuel byproduct. It's a fossil fuel product. You take natural gas, split it in a process called steam reforming, you get hydrogen and CO2 emissions. Green hydrogen only exists in very small quantities these days and for many years to come it'll be needed to first replace existing natural gas based hydrogen and to decarbonize industries like steel. There's basically a consensus among energy experts these days that hydrogen in cars is a dead end.

boringg 5y ago

3 main sources. 1- Natural Gas 2- Renewable Natural Gas (capping waste emissions from waste water treatment or municipal solid waste and coverting to Hydrogen). Net negative CO2 but smaller supply 3- Electrolysis (electricity + water). Source of electricity determines the cleanliness of the H2. Still requires water which is not ideal (especially in california)