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Assuming it is running on green hydrogen, how far could a Tesla Model 3 go on the electricity used to generate the hydrogen to go 2k km?

solardev 4y ago
About twice as far for a given amount of energy input, BUT that's leaving out the energy density of hydrogen fuel cells vs li-ion batteries. For grid storage purposes, batteries might be more efficient. But for automotive purposes, for an EV to go as far as a hydrogen vehicle, it'd have to be much bigger & heavier. In a sense, hydrogen makes the grid work harder, but once it does, you can squeeze it into a smaller/lighter package that can go much further than a similarly sized EV. Edit: A readable primer: https://www.theautochannel.com/news/2021/11/03/1066723-toyota-s-chief-scientist-hydrogen-vs-lithium-ion-batteries-why.html https://www.theautochannel.com/news/2021/11/03/1066723-toyot...
- bryanlarsen 4y ago
  A hydrogen Mirai is heavier than a Model 3 of comparable range.
BLKNSLVR 4y ago
I'm assuming you're asking because the electricity required to generate the hydrogen to power the car would be (much) more efficiently used to directly power the car. ie. electricity is being used as a process mid-point rather than end-result. I hear a bit of cynicism about hydrogen being touted by traditional automotive and fossil fuel companies because the business case around it is essentially the same as fossil fuels, where re-charging an electric car can be done at home "for free" (pending a number of dependencies being met), and I agree that it could be a half-step forwards rather than a full-step. But I also believe that it's best to have more than one option, and there are likely to be wildly varying use cases in which each option can an obvious stand-out for different use cases. What other trade-offs are there in hydrogen vs electric engines? (dependence on rare-earths being one negative on the electric side, but are there also rare-earths required for hydrogen engines or the generation of hydrogen?) What are the use cases? city driving, country driving, buses, trucks, towing, rail, light aircraft, passenger aircraft, military.
- MegaDeKay 4y ago
  Here's another trade-off: performance in cold weather. This coming from someone expecting a low of -18C tonight, and winter doesn't officially start for over another month. "The manager also points to another advantage that will save costs in the manufacture of vehicles: the fuel cell generates heat that can be used both to replace the car’s heating and air conditioning, which would also mean greater energy savings" Cold weather is really hard on batteries and can significantly impact range. On top of that is the extra draw on the batteries to run the heater necessary to keep the occupants from freezing. The one upside of the gasoline engine's inefficiency is harnessing the heat it gives off to keep the interior warm. The amount of heat that requires at highway speeds on a -35C day is... substantial.

solardev 4y ago

About twice as far for a given amount of energy input, BUT that's leaving out the energy density of hydrogen fuel cells vs li-ion batteries. For grid storage purposes, batteries might be more efficient. But for automotive purposes, for an EV to go as far as a hydrogen vehicle, it'd have to be much bigger & heavier. In a sense, hydrogen makes the grid work harder, but once it does, you can squeeze it into a smaller/lighter package that can go much further than a similarly sized EV. Edit: A readable primer: https://www.theautochannel.com/news/2021/11/03/1066723-toyota-s-chief-scientist-hydrogen-vs-lithium-ion-batteries-why.html https://www.theautochannel.com/news/2021/11/03/1066723-toyot...

bryanlarsen 4y ago
A hydrogen Mirai is heavier than a Model 3 of comparable range.

BLKNSLVR 4y ago

I'm assuming you're asking because the electricity required to generate the hydrogen to power the car would be (much) more efficiently used to directly power the car. ie. electricity is being used as a process mid-point rather than end-result. I hear a bit of cynicism about hydrogen being touted by traditional automotive and fossil fuel companies because the business case around it is essentially the same as fossil fuels, where re-charging an electric car can be done at home "for free" (pending a number of dependencies being met), and I agree that it could be a half-step forwards rather than a full-step. But I also believe that it's best to have more than one option, and there are likely to be wildly varying use cases in which each option can an obvious stand-out for different use cases. What other trade-offs are there in hydrogen vs electric engines? (dependence on rare-earths being one negative on the electric side, but are there also rare-earths required for hydrogen engines or the generation of hydrogen?) What are the use cases? city driving, country driving, buses, trucks, towing, rail, light aircraft, passenger aircraft, military.

MegaDeKay 4y ago
Here's another trade-off: performance in cold weather. This coming from someone expecting a low of -18C tonight, and winter doesn't officially start for over another month. "The manager also points to another advantage that will save costs in the manufacture of vehicles: the fuel cell generates heat that can be used both to replace the car’s heating and air conditioning, which would also mean greater energy savings" Cold weather is really hard on batteries and can significantly impact range. On top of that is the extra draw on the batteries to run the heater necessary to keep the occupants from freezing. The one upside of the gasoline engine's inefficiency is harnessing the heat it gives off to keep the interior warm. The amount of heat that requires at highway speeds on a -35C day is... substantial.