6 ms·

OTOH, using the model 3 as an example, you have to drive around 480kg of batteries all the time, while the same energy (75kWh/270MJ) in hydrogen would only amou

OTOH, using the model 3 as an example, you have to drive around 480kg of batteries all the time, while the same energy (75kWh/270MJ) in hydrogen would only amount to less than 2 kg.

SigmundA 5y ago
You won't get 75Wh to the wheel with 2kg and the hydrogen tanks and fuel cells have weight.
- bildung 5y ago
  Yes, obviously, but even then batteries are multiple times heavier. A fuel cell for this size is about 50kg currently, and a tank 50-80kg. The Mirai has a tank for 5kg hydrogen which weighs about 90kg: https://en.wikipedia.org/wiki/Toyota_Mirai https://en.wikipedia.org/wiki/Toyota_Mirai
  - SigmundA 5y ago
    Mirai: 1,850 kg Model 3 (Long-Range Dual-Motor): 1,847kg I am going to guess it's all the structure needed to protect the 10,000 psi hydrogen tanks.
    - bildung 5y ago
      Or you don't guess, follow the link instead and find out the Mirai is a) a bigger car and b) a hybrid, complete with electric motor and battery pack.
      - SigmundA 5y ago
        The Mirai has a 1.6 kwh battery pack because the fuel cell cannot output the needed power for acceleration and to allow regenerative braking. It runs on the electric motor alone just like a Tesla. But yeah so add the buffer battery in your weight calculations needed for a fuel cell vehicle. Pretty minor difference in size, unclear how that translates into usable space: Mirai Length 4,890 mm Width 1,815 mm Height 1,535 mm Model 3 Length 4,694 mm Width 1,849 mm Height 1,443 mm Also note the Mirai has a single 113kw motor (even with buffer battery to help) while the long range single motor model 3 is 211kw and only weighs 1730kg, I actually posted the heaviest performance AWD model 3. The Tesla completely outperforms the Mirai in cost, weight, ease of charging and performance.
        bildung 5y ago
        Nothing of this is relevant for the question of the weight of a hydrogen tank.
        SigmundA 5y ago
        Seem pretty relevant to look at the final weight, cost and performance of a vehicle when claiming fuel cells are superior to batteries due to hydrogens weight. Bottom line your example hydrogen fuel cell car weighs with a smaller motor more than a equivalent battery powered one, the question is why if hydrogen is so much lighter than a lithium battery?
      - jsight 5y ago
        Doesn't the Mirai have less passenger and cargo room than the 3 due to the inherent packaging issues with hydrogen?
    - Robotbeat 5y ago
      Why is this down-voted? It’s correct, even though it is counter-intuitive! The battery electric Model 3 LR gets more range and weighs less (while also being MUCH faster and cheaper to operate and more convenient to charge...).
  - albrewer 5y ago
    I design pressure vessel for a living. At the pressures required for hydrogen, required vessel wall thickness goes up really fast as diameter increases. I commented elsewhere about the weights required for a tractor trailer - to carry the volume required and maintain the same refill range, you'd need an 11,000kg cylinder to contain the hydrogen.
bryanlarsen 5y ago
The Toyota Mirai Hydrogen car is slightly heavier than a Model 3.
Robotbeat 5y ago
Ironically, at least last time I checked 1-2 years ago, the Long Range Model 3 weighs less than the hydrogen Mirai and has more range. Doesn’t matter what theoretical weight of hydrogen is when you have so much overhead the battery version weighs less! this is because: 1) hydrogen must be compressed. The compressed tank has to have high margins so it’s safe on the road. That means a much heavier tank than you might think 2) the fuel cell itself is expensive and weighs a lot! 3) fuel cells are MUCH less efficient so the useful energy isn’t what you think it is. That also means a lot of heat needs to be rejected which means: 4) heavy radiator (whose cooling also compromises aerodynamics), air filter and handling, you still need a lithium battery in there to handle regenerative braking and bursts of power, a bunch of high pressure hydrogen-rated valves which aren’t lightweight, etc. May as well look at the weight of electrons in a battery as just look at the weight of hydrogen gas in a hydrogen car...
tigershark 5y ago
I’ve seen this misinformation repeated everywhere in this thread. It’s simply not true, stop repeating this nonsense. Another user posted the calculations for the weight of a pressure vessel needed for the hydrogen storage and it explains why current hydrogen cars are more heavy than long range battery cars. Even accounting for more efficient storage for the trucks the weight needed for hydrogen is similar to what is needed with the batteries. Please stop with this nonsense that 480kg of batteries are equivalent to 2 kg of hydrogen.

OTOH, using the model 3 as an example, you have to drive around 480kg of batteries all the time, while the same energy (75kWh/270MJ) in hydrogen would only amount to less than 2 kg.

SigmundA 5y ago

You won't get 75Wh to the wheel with 2kg and the hydrogen tanks and fuel cells have weight.

bildung 5y ago
Yes, obviously, but even then batteries are multiple times heavier. A fuel cell for this size is about 50kg currently, and a tank 50-80kg. The Mirai has a tank for 5kg hydrogen which weighs about 90kg: https://en.wikipedia.org/wiki/Toyota_Mirai https://en.wikipedia.org/wiki/Toyota_Mirai
- SigmundA 5y ago
  Mirai: 1,850 kg Model 3 (Long-Range Dual-Motor): 1,847kg I am going to guess it's all the structure needed to protect the 10,000 psi hydrogen tanks.
  - bildung 5y ago
    Or you don't guess, follow the link instead and find out the Mirai is a) a bigger car and b) a hybrid, complete with electric motor and battery pack.
    - SigmundA 5y ago
      The Mirai has a 1.6 kwh battery pack because the fuel cell cannot output the needed power for acceleration and to allow regenerative braking. It runs on the electric motor alone just like a Tesla. But yeah so add the buffer battery in your weight calculations needed for a fuel cell vehicle. Pretty minor difference in size, unclear how that translates into usable space: Mirai Length 4,890 mm Width 1,815 mm Height 1,535 mm Model 3 Length 4,694 mm Width 1,849 mm Height 1,443 mm Also note the Mirai has a single 113kw motor (even with buffer battery to help) while the long range single motor model 3 is 211kw and only weighs 1730kg, I actually posted the heaviest performance AWD model 3. The Tesla completely outperforms the Mirai in cost, weight, ease of charging and performance.
      - bildung 5y ago
        Nothing of this is relevant for the question of the weight of a hydrogen tank.
        SigmundA 5y ago
        Seem pretty relevant to look at the final weight, cost and performance of a vehicle when claiming fuel cells are superior to batteries due to hydrogens weight. Bottom line your example hydrogen fuel cell car weighs with a smaller motor more than a equivalent battery powered one, the question is why if hydrogen is so much lighter than a lithium battery?
    - jsight 5y ago
      Doesn't the Mirai have less passenger and cargo room than the 3 due to the inherent packaging issues with hydrogen?
  - Robotbeat 5y ago
    Why is this down-voted? It’s correct, even though it is counter-intuitive! The battery electric Model 3 LR gets more range and weighs less (while also being MUCH faster and cheaper to operate and more convenient to charge...).
- albrewer 5y ago
  I design pressure vessel for a living. At the pressures required for hydrogen, required vessel wall thickness goes up really fast as diameter increases. I commented elsewhere about the weights required for a tractor trailer - to carry the volume required and maintain the same refill range, you'd need an 11,000kg cylinder to contain the hydrogen.

bryanlarsen 5y ago

The Toyota Mirai Hydrogen car is slightly heavier than a Model 3.

Robotbeat 5y ago

Ironically, at least last time I checked 1-2 years ago, the Long Range Model 3 weighs less than the hydrogen Mirai and has more range. Doesn’t matter what theoretical weight of hydrogen is when you have so much overhead the battery version weighs less! this is because: 1) hydrogen must be compressed. The compressed tank has to have high margins so it’s safe on the road. That means a much heavier tank than you might think 2) the fuel cell itself is expensive and weighs a lot! 3) fuel cells are MUCH less efficient so the useful energy isn’t what you think it is. That also means a lot of heat needs to be rejected which means: 4) heavy radiator (whose cooling also compromises aerodynamics), air filter and handling, you still need a lithium battery in there to handle regenerative braking and bursts of power, a bunch of high pressure hydrogen-rated valves which aren’t lightweight, etc. May as well look at the weight of electrons in a battery as just look at the weight of hydrogen gas in a hydrogen car...

tigershark 5y ago

I’ve seen this misinformation repeated everywhere in this thread. It’s simply not true, stop repeating this nonsense. Another user posted the calculations for the weight of a pressure vessel needed for the hydrogen storage and it explains why current hydrogen cars are more heavy than long range battery cars. Even accounting for more efficient storage for the trucks the weight needed for hydrogen is similar to what is needed with the batteries. Please stop with this nonsense that 480kg of batteries are equivalent to 2 kg of hydrogen.