51–60 of 343 posts
Earlier quoted context omitted.
1 kg of (electrically produced) hydrogen costs more than 1000 gallons of desal. (1 kg of hydrogen would make a few gallons of water)
edit: misinterpreted "desal" as diesel rather than desalinated water. Well that's just not at all true. Hydrogen by electrolysis costs https://www.nrel.gov/docs/fy04osti/36734.pdf
I was responding to point 7, not comparing hydrogen to diesel.
Hydrogen 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…
Hydrogen 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
Earlier quoted context omitted.
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.
> Never needing to fill up is even better. And which technology allows for that? The cars "running on water" that new age alien enthusiasts are always on about?
The 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…
A theory like that ignores most of known basic physics. What would the energy source be? It does not matter what chemical or electrochemical reactions are possible in general, what matters is where does the energy come from. Water does not contain any energy. (Not any chemical energy that can easily be extracted. Of course it contains energy in the sense that E=MC^2, but in that sense we have about the same chance to…
Saying this ignores basic physics is like saying gasoline engines ignore basic physics. No one is saying that it's free energy. The question is, what is the energy to produce/recycle the alloy? How many miles can you get out of a reasonable supply of the alloy before replacing it? If those numbers are good enough, maybe they'll perform better than battery vehicles. And so I'm asking what's the state of that research.
Following 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…
I 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…
“As an example, a 100kWh battery will give a potential range of 250 miles and, in order to produce that battery, it will take around 20 tonnes of CO2,” he said. “A typical battery lasts for 150,000 miles, so that equates to around 83g/km of CO2. Then, when you take into account charging over that same distance, the same battery car will deliver 124g/km of CO2 over its lifetime.”
By comparison, Auto Express says that a recent study found that a Toyota Mirai hydrogen fuel cell car produces around 120g/km of CO2 over its lifetime when the manufacturing process is taken into account. But if hydrogen were to be produced by renewable energy, that figure could be reduced significantly.”
Source: https://www.theweek.co.uk/electric-cars/101196/hydrogen-fuel...
I 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…
The issue of charging was also there with BEVs, until Tesla straight up built a huge network of superchargers. The players in hydrogen say they will do the same. But for personal vehicles, hydrogen won't math out, it's greatest advantage is its energy density for trucks. It's for long range trucks that we will see hydrogen first. Green hydrogen will act as energy storage, big renewables grids can dump excess into gre…
https://www.carboncommentary.com/blog/2020/6/17/renewables-p...
Lots of comments on this thread that reveal folks are up to date with the state of hydrogen infrastructure c. 2017. It's changing really fast as billions of dollars are poured into R&D and pilot projects. For example, storage and transport:
https://uk.reuters.com/article/uk-japan-hydrogen-chiyoda-cor...
Siemens has pledged to make turbines that run on 100% hydrogen by 2030: https://new.siemens.com/global/en/company/stories/energy/hyd...
Hydrogen trains: https://www.snam.it/en/Media/Press-releases/Agreement_Alstom...
Hydrogen in steelmaking: https://www.spglobal.com/platts/en/market-insights/latest-ne...
I could post 15 more. Our collective priors were well-grounded just a couple years ago, but it is time for a big update.
I 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…
When you consider the energy required to produce lithium ion batteries they are actually worse than fuel cells from an emissions perspective: “As an example, a 100kWh battery will give a potential range of 250 miles and, in order to produce that battery, it will take around 20 tonnes of CO2,” he said. “A typical battery lasts for 150,000 miles, so that equates to around 83g/km of CO2. Then, when you take into account…