4 ms·

This would work for cars.

danans 7y ago
All fuel cell cars are also electric cars in that they use batteries and electric drivetrains in addition to the hydrogen fuel cell itself. The result is more complexity and hence cost, which is one big reason fuel cell cars haven't taken off. The other reason is the lack of sufficient hydrogen distribution infrastructure. Cars need a dense network of refueling points for convenience. For EVs, this already exists in the form of the existing electric grid and local distribution network (yes, I know it's harder for apartment dwellers right now). A similarly dense hydrogen distribution network doesn't exist, and would have to built from scratch. Airplanes, on the other hand, have far fewer refueling points (they're all at airports), so it's a lot easier to build those. In the future, as the cost and size of fuel cell tech drops, one can maybe see them being use for range extending applications for rapid refueling in long distance drives, but then again, rapid charging and high range EVs are making even that advantage somewhat moot.
- bobthepanda 7y ago
  IMO fuel cells could also be better for freighters, which can’t use batteries for weight reasons as well.
- BerislavLopac 7y ago
  > A similarly dense hydrogen distribution network doesn't exist, and would have to built from scratch. Or we can add hydrogen to the existing fuels on traditional petrol stations.
  - danans 7y ago
    Sure, but those stations would still need a invasive and expensive retrofit, adding new underground tanks. You'd also need a new fleet of hydrogen delivery tankers to parallel existing fleet of fuel delivery tankers. And remember that compressed hydrogen's energy density is 5x lower than gasoline [1], so to store the same amount of energy as gasoline, you need 5x the amount of storage volume on site to store the same amount of energy. Fuel cell drivetrains are about double the efficiency of typical gas engines, so that might bring the storage needs down to 2.5x the storage needs for gasoline, but then you also need special equipment to keep the hydrogen contained (it's harder to contain than liquid fuel). You also need 2.5x the number of hydrogen tankers to move that fuel to the stations, or 2.5x the frequency of tanker trips. Compare that to the relatively minimal cost of attaching an EV charging station to an existing building's power supply, and there's not much comparison. At most, you need to upgrade transformers and the local power substations to handle potentially higher demand at peak charging hours, but even that can be done incrementally based on demand profile changes, and mitigated substantially with smart coordinated charging during off-peak hours. 1. https://en.wikipedia.org/wiki/Energy_density#/media/File:Energy_density.svg https://en.wikipedia.org/wiki/Energy_density#/media/File:Ene...
    - BerislavLopac 7y ago
      Oh absolutely, the technology will require plenty of updating. But in a typical distribution system the logistics is usually a much more complex and difficult issue. And hydrogen has enough similarities with the existing fuel (unlike electricity) to require barely any changes in the logistics.
      - danans 7y ago
        > And hydrogen has enough similarities with the existing fuel (unlike electricity) Electricity already has a regional and local distribution network. It is an "existing fuel" by definition.
ClumsyPilot 7y ago
The electrolysis and fuel cell process is significantly less efficient than charging/discharging batteries. It's also significantly less safe and more complex, while offering little benefit - cars are not that sensitive to the weight of batteries. For aircraft, the equasion is different because there weight is directly proportional to fuel use.
rad_gruchalski 7y ago
Toyota has a new version of Mirai coming out in 2021. Bosch and BMW are also looking into fuel cells.

All fuel cell cars are also electric cars in that they use batteries and electric drivetrains in addition to the hydrogen fuel cell itself. The result is more complexity and hence cost, which is one big reason fuel cell cars haven't taken off. The other reason is the lack of sufficient hydrogen distribution infrastructure. Cars need a dense network of refueling points for convenience. For EVs, this already exists in the form of the existing electric grid and local distribution network (yes, I know it's harder for apartment dwellers right now). A similarly dense hydrogen distribution network doesn't exist, and would have to built from scratch. Airplanes, on the other hand, have far fewer refueling points (they're all at airports), so it's a lot easier to build those. In the future, as the cost and size of fuel cell tech drops, one can maybe see them being use for range extending applications for rapid refueling in long distance drives, but then again, rapid charging and high range EVs are making even that advantage somewhat moot.

bobthepanda 7y ago
IMO fuel cells could also be better for freighters, which can’t use batteries for weight reasons as well.
BerislavLopac 7y ago
> A similarly dense hydrogen distribution network doesn't exist, and would have to built from scratch. Or we can add hydrogen to the existing fuels on traditional petrol stations.
- danans 7y ago
  Sure, but those stations would still need a invasive and expensive retrofit, adding new underground tanks. You'd also need a new fleet of hydrogen delivery tankers to parallel existing fleet of fuel delivery tankers. And remember that compressed hydrogen's energy density is 5x lower than gasoline [1], so to store the same amount of energy as gasoline, you need 5x the amount of storage volume on site to store the same amount of energy. Fuel cell drivetrains are about double the efficiency of typical gas engines, so that might bring the storage needs down to 2.5x the storage needs for gasoline, but then you also need special equipment to keep the hydrogen contained (it's harder to contain than liquid fuel). You also need 2.5x the number of hydrogen tankers to move that fuel to the stations, or 2.5x the frequency of tanker trips. Compare that to the relatively minimal cost of attaching an EV charging station to an existing building's power supply, and there's not much comparison. At most, you need to upgrade transformers and the local power substations to handle potentially higher demand at peak charging hours, but even that can be done incrementally based on demand profile changes, and mitigated substantially with smart coordinated charging during off-peak hours. 1. https://en.wikipedia.org/wiki/Energy_density#/media/File:Energy_density.svg https://en.wikipedia.org/wiki/Energy_density#/media/File:Ene...
  - BerislavLopac 7y ago
    Oh absolutely, the technology will require plenty of updating. But in a typical distribution system the logistics is usually a much more complex and difficult issue. And hydrogen has enough similarities with the existing fuel (unlike electricity) to require barely any changes in the logistics.
    - danans 7y ago
      > And hydrogen has enough similarities with the existing fuel (unlike electricity) Electricity already has a regional and local distribution network. It is an "existing fuel" by definition.

ClumsyPilot 7y ago

The electrolysis and fuel cell process is significantly less efficient than charging/discharging batteries. It's also significantly less safe and more complex, while offering little benefit - cars are not that sensitive to the weight of batteries. For aircraft, the equasion is different because there weight is directly proportional to fuel use.

rad_gruchalski 7y ago

Toyota has a new version of Mirai coming out in 2021. Bosch and BMW are also looking into fuel cells.