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After many false starts, hydrogen power might now bear fruit
21–30 of 343 posts
Re: After many false starts, hydrogen power might now bear fruit
#22The article didn't touch on this at all, so has anyone heard updates on attempts at doing in-vehicle hydrogen production from water and some sort of reactant? It's been years since I saw something on it, but if I recall, it used some pellets made of certain metals that react with the water to produce hydrogen. You'd fill the tank with water, and after some number of fill ups you'd also need to replenish the pellets which could be sent off for recycling.
Edit: I found an article about this. It appears to have been developed by the military and has been licensed out for more development: https://techxplore.com/news/2019-07-h2-power-hydrogen-fuel-s...
Re: After many false starts, hydrogen power might now bear fruit
#23I think article missed a really large sector which uses coal and produces millions of tons of co2 each year, That is cement industry. Heating clinker to produce cement is energy intensive long process, where big investments towards technology for using Hydrogen can be fruitful.
Why not use electricity or natural gas for heating? Both would be more efficient than using hydrogen as an intermediate step.
Re: After many false starts, hydrogen power might now bear fruit
#24I've been diving into this literature a bit recently, and it's been mostly encouraging. Affordable clean energy is realistic.
Clean energy sources are typically the cheapest sources of energy [0]. The intermittent production issue is solvable: At ~150 $/kWh storage, a combination of storage and renewables is the cheapest energy source 95% of the time [1].
The cost of different energy storage methods is coming down exponentially [2]. A combination of Li-Ion battery (short-term), pumped hydro (medium-term) and hydrogen (long-term, i.e. seasonal) storage is probably how to smooth out the burstiness of renewable energy production eventually [3].
When green hydrogen infrastructure is commonplace, the hydrogen can also be used to make synthetic jet fuel and feedstocks for the chemical industry.
[0] https://en.wikipedia.org/wiki/Cost_of_electricity_by_source
[1] https://www.cell.com/joule/fulltext/S2542-4351(19)30300-9
[2] https://www.nature.com/articles/nenergy2017110/figures/1?pro...
[3] https://www.sciencedirect.com/science/article/pii/S254243511...
Re: After many false starts, hydrogen power might now bear fruit
#25The article didn't touch on this at all, so has anyone heard updates on attempts at doing in-vehicle hydrogen production from water and some sort of reactant? It's been years since I saw something on it, but if I recall, it used some pellets made of certain metals that react with the water to produce hydrogen. You'd fill the tank with water, and after some number of fill ups you'd also need to replenish the pellets w…
In that case you'd be better of using methanol which can also be used in fuel cells.
Re: After many false starts, hydrogen power might now bear fruit
#26Hydrogen production is almost entirely produced from fossil fuels currently. Its not really a low carbon energy source unless electrolysis can be made much more efficient. Its a shame this article didn't examine the production side of hydrogen.
A recent report [1] looked at the efficiencies of generating hydrogen at a waste water treatment plant to lower production costs. The WWTP provides the water and uses the oxygen that is also produced by electrolysis to increase the efficiency of the biological treatment process vs air. Some of the electricity for the electrolysis can also be sourced from biogas produced by the WWTP.
[1] https://www.jacobs.com/sites/default/files/2020-06/jacobs-ya...
Re: After many false starts, hydrogen power might now bear fruit
#27I used to drive a hydrogen car once in a while a few years ago. It was nice to fill the car in a few minutes and get about 300km of range, but that was it. With the hydrogen you have so few refueling stations, they are very expensive, that range anxiety is a thing. To not improve things, reliability is very poor. My work had a hydrogen refueling station on its parking. It was often broken and actually a bit scary to…
And you always have full (trip) range every morning with an EV. Yes, filling up in 5 minutes is better than 20. Never needing to fill up is even better.
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Re: After many false starts, hydrogen power might now bear fruit
#28Hydrogen has an efficiency problem. You need to convert other forms of energy to hydrogen at a loss. Then you need to store it and transport it, which is costly and may impose quite some energy cost for cooling or compression. Then you need to convert it back to electricity, also at a loss. If you start at electricity, the electrical grid and batteries would be much more efficient. If you start at oil or gas, you cou…
sounds like Iceland would do well to export hydrogen from electrolysis
Transporting hydrogen is expensive. It also has a tendency to leak.
Re: After many false starts, hydrogen power might now bear fruit
#29Following Musk's thinking... i'd really like to see that energy density volume vs mass chart adjusted for average vehicle weight. i.e see the total system, engine, storage components and fuel converter etc.
On that graph, compared to petrol, liquid hydrogen appears to be about 4x larger by volume but interestingly only 2/5ths of the weight.
The electric motors are lighter sure, but then what about the mass and volume of the compressed storage tank and the fuel cell itself? difficult to know if it starts to gain on IC engine again. lots of questions that make that graph feel pretty meaningless.
Re: After many false starts, hydrogen power might now bear fruit
#30Okay, going to chime in here because this is categorically wrong on so many fronts. Tldr: Impossible for civilization to make an instantaneous non-gradual switch to hydrogen fuel cells. People like Hydrogen because they're hyped about how it is: - Clean - Plentiful - Emission-less Hydrogen is difficult to handle. - Unwieldy as a gas - Boils at 20 degrees F/ - 6 degrees C / ~420 Kelvins - Tough to maintain at a high p…
Hydrogen might make some sense for long haul trucks. Then you need fewer refueling stations on only the major routes. You could also generate the hydrogen locally by using electricity. Alternatively you could equip the trucks with batteries and connect them to the electrical grid via overhead lines similar to trains for recharging. Combined with autonomous driving those trucks could go non-stop and leave the highway…
2nd option exists and is called rolling highway ;)