6 ms·

For reference, the Toyota Mirai goes 100 km on 0.85 kg of hydrogen [0] [0] https://arstechnica.com/cars/2023/08/many-evs-outperform-epa-estimates-in-this-real-

by inasio 3y ago

For reference, the Toyota Mirai goes 100 km on 0.85 kg of hydrogen [0] [0] https://arstechnica.com/cars/2023/08/many-evs-outperform-epa-estimates-in-this-real-world-efficiency-testing/ https://arstechnica.com/cars/2023/08/many-evs-outperform-epa...

puchatek 3y ago
Cars are the least interesting machines to benefit from a hydrogen economy IMO
- inasio 3y ago
  I don't disagree, but I think the above number is an interesting datapoint, I wish we had a similar way to compare range in airplanes (jet fuel vs H)
- squaredot 3y ago
  I completely agree with you. I point you to this interesting article from which I usually get my arguments https://ethz.ch/en/news-and-events/eth-news/news/2021/11/hydrogen-for-ground-transportation-and-heating-is-a-bad-idea.html https://ethz.ch/en/news-and-events/eth-news/news/2021/11/hyd...
djaychela 3y ago
Which sounds great... until you find that to produce that much hydrogen takes 46.41kWh by electrolysis. My renault Zoe would do about 176 miles (283km) on the same electricity put straight into the battery. Hydrogen cars do not make sense unless the electricity is free, and even then there are lots of difficulties not present in a BEV.
- _hypx 3y ago
  You cannot magically put electricity directly into the battery. There is a significant loss between production and powering the wheels. This is the biggest source of misunderstanding about the subject.
  - squaredot 3y ago
    When the subject arise I usually point at the following interesting article https://ethz.ch/en/news-and-events/eth-news/news/2021/11/hydrogen-for-ground-transportation-and-heating-is-a-bad-idea.html https://ethz.ch/en/news-and-events/eth-news/news/2021/11/hyd...
    - _hypx 3y ago
      That has nothing to do with the subject at hand. You cannot charge a battery at 100% efficiency, especially from the source electricity. People are simply creating an apples-to-oranges comparison here. You're just distracting from this fact.
      - djaychela 3y ago
        There are of course losses when charging a battery, but they are orders of magnitude larger when talking about the creation of hydrogen versus the charging of a battery. Hydrogen simply isn't a good idea for a number of reasons, and the energy needed to separate it from water is just one of them. Quoting "apples to oranges" here ignores the massive inefficiency in other stages of the process of storing and distribution of hydrogen, which is difficult and expensive to do. The distribution of electricity is much more efficient and cheaper.
        _hypx 3y ago
        Factually no. There is no straightforward method of taking energy from renewable sources and getting it to a charging station. In reality, this is one of the hardest parts of green energy. You simply have to ask the question, "what happens when the wind is not blowing or the sun is not shining?" In fact, this is a total inversion of reality, bordering on science denial. The process of making and storing hydrogen is a straightforward process. It is trying to this with only electricity that is very hard.
        _aavaa_ 3y ago
jillesvangurp 3y ago
Most EVs go a lot further on the 50kwh * 0.85 = 42 kwh it would take to produce that. Most EVs with a battery that size would be doing 150ish miles or around 200km. That kind of shows the problem with hydrogen and transport. With an expensive and ideal hydrolyser (using the numbers in the article) you are still requiring twice the energy per km. Of course things not being ideal, it's more like 4x with the 80kwh / kg hydrolyser this company advertises. Now we're talking 80*0.85 = 68 kwh. That's typical for a lot of mid range EVs (including Teslas) with a range of 250 miles or better; or about 400km. 4x the energy + all the additional cost. Sure it will only cost a 85 cents per 100 km. But you could be driving for 21 cents per 100 km.
- sbradford26 3y ago
  You covered the most important detail that I think most people skip and that is that hydrogen is just a very inefficient battery if you are utilizing green hydrogen. With the intrinsic inefficiencies of generating green hydrogen and the of fuel cells you will always end up using 3-4x the amount of energy versus just charging an EV directly. That is even before you deal with transportation, storage, and pressurization of the hydrogen. Now cheap hydrogen can be useful for industrial processes and aerospace so seeing the cost come down is still very good.

by inasio 3y ago

puchatek 3y ago

Cars are the least interesting machines to benefit from a hydrogen economy IMO

inasio 3y ago
I don't disagree, but I think the above number is an interesting datapoint, I wish we had a similar way to compare range in airplanes (jet fuel vs H)
squaredot 3y ago
I completely agree with you. I point you to this interesting article from which I usually get my arguments https://ethz.ch/en/news-and-events/eth-news/news/2021/11/hydrogen-for-ground-transportation-and-heating-is-a-bad-idea.html https://ethz.ch/en/news-and-events/eth-news/news/2021/11/hyd...

djaychela 3y ago

Which sounds great... until you find that to produce that much hydrogen takes 46.41kWh by electrolysis. My renault Zoe would do about 176 miles (283km) on the same electricity put straight into the battery. Hydrogen cars do not make sense unless the electricity is free, and even then there are lots of difficulties not present in a BEV.

_hypx 3y ago
You cannot magically put electricity directly into the battery. There is a significant loss between production and powering the wheels. This is the biggest source of misunderstanding about the subject.
- squaredot 3y ago
  When the subject arise I usually point at the following interesting article https://ethz.ch/en/news-and-events/eth-news/news/2021/11/hydrogen-for-ground-transportation-and-heating-is-a-bad-idea.html https://ethz.ch/en/news-and-events/eth-news/news/2021/11/hyd...
  - _hypx 3y ago
    That has nothing to do with the subject at hand. You cannot charge a battery at 100% efficiency, especially from the source electricity. People are simply creating an apples-to-oranges comparison here. You're just distracting from this fact.
    - djaychela 3y ago
      There are of course losses when charging a battery, but they are orders of magnitude larger when talking about the creation of hydrogen versus the charging of a battery. Hydrogen simply isn't a good idea for a number of reasons, and the energy needed to separate it from water is just one of them. Quoting "apples to oranges" here ignores the massive inefficiency in other stages of the process of storing and distribution of hydrogen, which is difficult and expensive to do. The distribution of electricity is much more efficient and cheaper.
      - _hypx 3y ago
        Factually no. There is no straightforward method of taking energy from renewable sources and getting it to a charging station. In reality, this is one of the hardest parts of green energy. You simply have to ask the question, "what happens when the wind is not blowing or the sun is not shining?" In fact, this is a total inversion of reality, bordering on science denial. The process of making and storing hydrogen is a straightforward process. It is trying to this with only electricity that is very hard.
        _aavaa_ 3y ago

jillesvangurp 3y ago

Most EVs go a lot further on the 50kwh * 0.85 = 42 kwh it would take to produce that. Most EVs with a battery that size would be doing 150ish miles or around 200km. That kind of shows the problem with hydrogen and transport. With an expensive and ideal hydrolyser (using the numbers in the article) you are still requiring twice the energy per km. Of course things not being ideal, it's more like 4x with the 80kwh / kg hydrolyser this company advertises. Now we're talking 80*0.85 = 68 kwh. That's typical for a lot of mid range EVs (including Teslas) with a range of 250 miles or better; or about 400km. 4x the energy + all the additional cost. Sure it will only cost a 85 cents per 100 km. But you could be driving for 21 cents per 100 km.

sbradford26 3y ago
You covered the most important detail that I think most people skip and that is that hydrogen is just a very inefficient battery if you are utilizing green hydrogen. With the intrinsic inefficiencies of generating green hydrogen and the of fuel cells you will always end up using 3-4x the amount of energy versus just charging an EV directly. That is even before you deal with transportation, storage, and pressurization of the hydrogen. Now cheap hydrogen can be useful for industrial processes and aerospace so seeing the cost come down is still very good.