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| ▲ | praseodym 4 days ago | parent | next [-] |
| > Yes, you can refill quicker Unless the hydrogen fueling nozzle freezes to the car, which is apparently quite common in high humidity weather and/or when multiple cars are fueled consecutively. See e.g. https://www.sciencedirect.com/science/article/pii/S036031992... |
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| ▲ | petertodd 4 days ago | parent [-] | | That's just a minor problem, not a fatal flaw. Obviously you can fix that with a small heater for negligible energy cost. | | |
| ▲ | praseodym 4 days ago | parent | next [-] | | Commercially available solutions seem to use a flow of nitrogen to purge condensation from the nozzle, which is quite a bit more complicated: https://www.weh.com/en_us/general-news/preventing-the-fuelin... | | |
| ▲ | petertodd 3 days ago | parent [-] | | Yes, to comply with paranoid hydrogen safety regulations cheaply. Also, note how the nitrogen is also being used to purge the entire line. Not just keep condensation away. With more engineering work an intrinsically safe PTC heater could be certified and used just fine. |
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| ▲ | Filligree 4 days ago | parent | prev [-] | | Now you have a heater in immediate proximity to hydrogen gas. It’s not impossible, but I think you’re underestimating the complexity of doing that safely. | | |
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| ▲ | lesuorac 4 days ago | parent | prev | next [-] |
| > Yes, you can refill quicker, but time to "refuel" EV's is dropping precipitously as well, and it's just all around safer than tanking around highly combustible liquid gas. I always think of I, Robot where the protagonist gets on a motorcycle and immediately their passenger complains about how dangerous gasoline is. While not for everybody, EVs have a really great property of being rechargable without much effort on your part. Just spend ~10 seconds plugging it in at home/work and then ~10 seconds unplugging it before your next time. Compared to waiting 20 minutes in line at Costco Gas to save 1 dollar. |
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| ▲ | philjohn 3 days ago | parent [-] | | And much cheaper to fill as well. On a pretty efficienct ICE that I had I was averaging about 20p per mile driven. On my EV I'm averaging 2.5p per mile driven. |
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| ▲ | grapesodaaaaa 4 days ago | parent | prev | next [-] |
| Let’s not forget that the highly combustible liquid gas either needs to be stored with complicated cooling or under immense pressure (feel free to disprove me if I haven’t kept up with technology). It can be done safely, but adds a lot of complexity on top of all the complexity needed for ICE engines. Your points are also great. |
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| ▲ | mbirth 4 days ago | parent [-] | | Add to that the problem of “boil off” / “pressure venting”. There are some cars that empty their hydrogen tanks on their own in about 2 weeks. Just because of this issue. There are new ways to store hydrogen, but these also need external (=from a separate battery) electricity to release it again and the process is slow and doesn’t provide enough amperage, so it can only be used to slowly charge another big battery that is required for these cars to be able to drive. |
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| ▲ | mmooss 4 days ago | parent | prev | next [-] |
| > Hydrogen vehicles have not proven to match or even beat EV's in a lot of key metrics that matter Not yet. That is the nature of technological R&D - if we had the answers, we wouldn't be doing R&D. AI before the last decade or so didn't beat other computer technologies in key metrics; should they have stopped developing it? Fusion power doesn't beat fission and other options in key metrics; solar didn't beat other sources in key metrics, including costs, ... - should humanity have stopped developing those things? |
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| ▲ | philjohn 2 days ago | parent [-] | | Toyota have been researching hydrogen cars since the early 90's. Unless you can find a way to double their efficiency, and also get hydrogen down to close to 1:1 energy input to output it's just not an efficienct use of electricity. | | |
| ▲ | mmooss 2 days ago | parent [-] | | EVs were researched for decades before they came to fruition. That's the nature of research. |
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| ▲ | philwelch 4 days ago | parent | prev | next [-] |
| It's not really fair to compare the efficiency numbers directly that way. The efficiency for hydrogen is measured from the hydrogen fuel directly, but the efficiency of the EV is measured from the wall. In reality, generating electricity is about 40% efficient at best. Yes, there's also an efficiency cost to refining the hydrogen, but if we compare apples to apples and take a ton of LNG and use it to power an EV versus a hydrogen car, I doubt the EV is going to get more milage. |
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| ▲ | pipodeclown 4 days ago | parent | next [-] | | Sure but you should be comparing the goal end state, a world in which out energy consumption and generation is green, that's the whole point of our move to bev's and hydrogen. So you should be comparing energy generation by green means to power a BEV or using green energy to produce hydrogen to power a hydrogen car. In that world the whole energy production and consumption chain is about 3x as efficient for BEV, which in my mind means there is no way hydrogen is going to be competitive and we shouldn't waste valuable resources on persuing it. | |
| ▲ | philjohn 3 days ago | parent | prev [-] | | Hydrogen that doesn't come from the natural gas industry requires that very same electricity to be extracted from water - so they're operating from the same baseline in my efficiency calculations. | | |
| ▲ | philwelch 3 days ago | parent [-] | | But the electricity is generated by burning natural gas. | | |
| ▲ | philjohn 2 days ago | parent [-] | | Not 100%. A lot in the US, for sure, less in the EU where renewables are a much larger part of the grid, as is Nuclear (thanks to interconnects from France). And if we work at it that number might go the same way as Coal has within our lifetimes. |
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| ▲ | nautilius 4 days ago | parent | prev | next [-] |
| Efficiency is the standard red herring of the battery crowd - if efficiency was the prime motivation, we would all be driving bicycles and SUV or sportscars would not exist. What are your other metrics? It’s an electric drivetrain with all advantages, but with the range of a gasoline car. Refueling cNG or LNG is standard in Europe, LH2 works just fine. Google “burning Tesla” for that ridiculous take on why batteries would be inherently safe. |
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| ▲ | philjohn 4 days ago | parent | next [-] | | Except it's efficiency for the same class of vehicles we're talking about, so a bike is an apples to oranges comparison. Proton Exchange Membrane is 40-45% efficient. Generating hydrogen from electricity is 70% efficient - meaning for a kWh of input electricity you get 3x the motive power from a BEV. Then rolling out a refuelling network, with the high pressure tanks and expensive delivery mechanism, will cost far more than installing EV chargers - and that's before we even get onto the CURRENT penetration of EV chargers vs Hydrogen filling stations today (16 in the UK, 54 in the ENTIRE US, and not growing). Hydrogen might be the solution to emissions from haulage, but BEV's are more than good enough compared to the ICE cars they're replacing for 99.9% of motorists needs. Yes, I'm ignoring the "I need to drive 1000 miles without stopping for fuel, rest, using the bathroom, come back when an EV can do THAT" people. And on burning EV's, they catch fire at rates 20x lower than ICE cars, and LFP chemistry is far more resistant to thermal runaway. Now lets talk cost - over the life of the car the BEV will be cheaper to run. Filling a Mirai in the UK will cost you around £90 for 400 miles of range. Charging my EV6 from 0 to 100 will cost me £5.50 for 300 miles of range. We're talking near orders of magnitude difference in cost per mile here - it's almost an unfair advantage that you can charge an EV at home off peak for next to nothing. | |
| ▲ | crote 4 days ago | parent | prev | next [-] | | Range is almost entirely irrelevant. The average commute distance is 16 miles, and commutes over 50 miles are quite rare. This means a car with a range of 100 miles would cover the vast majority of use cases. Add some buffer for emergencies and cold weather, and even the 150-mile-range Nissan Leaf is more than enough. You could also look at once-a-year road trips, of course: a range of 250 to 300 miles is becoming quite common for mid-level SUVs. With current technologies that means a charging session of 30 minutes or so every 3.5 to 4 hours - and it's only getting better. For context, the EU-based commercial truckers have a 45-minute break every 4.5 hours, because non-stop driving for even longer than that poses a safety risk. BEVs aren't stuck in the 1990s anymore. Their range has significantly improved over the 60-mile range of the GM EV1. If 2025 BEV range is an issue for you, you are the outlier. | |
| ▲ | pipodeclown 4 days ago | parent | prev [-] | | Efficiency doesn't matter when you're literally pumping energetic liquid from the ground. It does matter when you need to build 150% more solar panels to produce the energy to create your energetic liquid/gas. | | |
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| ▲ | filmor 4 days ago | parent | prev [-] |
| How is that efficiency calculated, respectively? |
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| ▲ | philjohn 4 days ago | parent [-] | | https://www.sciencedirect.com/topics/engineering/fuel-cell-e... I believe all Hydrogen vehicles are using proton exchange membranes still, which have roughly 40-50% efficiency. And that's before you take into account that even the most cutting edge hydrogen refining processes are around 70% efficient. So 1kWh of energy input (electricity) will net you 3X the motive power when used directly in a BEV than first being coverted to hydrogen, and then converted back into electricity.[1] [1] 0.5*0.7 = 0.35. | | |
| ▲ | marcosdumay 4 days ago | parent | next [-] | | I don't think any hydrogen vehicle in actual use has a fuel cell (and if there's any, it's an incredibly rare exception). They are all internal combustion engines. Proton exchange membranes are very unreliable and expensive. They are also not power-dense, one that powers a bus will be very large. | | |
| ▲ | ch_sm 4 days ago | parent | next [-] | | It‘s actually the opposite: some hydrogen cars that use combustion exist, but they are really, really rare. Almost all hydrogen cars that are road legal use a fuel cell in combination with BEV parts to smooth out/extend power delivery. | |
| ▲ | pipodeclown 4 days ago | parent | prev [-] | | That is completely incorrect, it is the opposite. |
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| ▲ | fluidcruft 4 days ago | parent | prev [-] | | BEVs aren't 100% efficient though so it's closer to 2x rather than 3x. | | |
| ▲ | philjohn 4 days ago | parent [-] | | I’ve also gone for the max efficiency figures for the Hydrogen car. And that’s before we get to the fuel costs - £90 to go 400 miles in a Mirai, versus £5.50 to go 300 in an EV6. |
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