5 ms·
Cost to produce H2 from water, 50-55 kWh/kg Cost to liquefy H2 is 10-13 kWh/kg 1 Kg of H2 stores about 33 kWh of energy. More than 50% of the energy is wasted b
by briandw 2y ago
Cost to produce H2 from water, 50-55 kWh/kg
Cost to liquefy H2 is 10-13 kWh/kg
1 Kg of H2 stores about 33 kWh of energy.
More than 50% of the energy is wasted before transport, storage, boil off etc are concerned.
H2 does not make any sense whatever.
- akoboldfrying 2y agoWell, the article actually admits that 95% of hydrogen produced in the US is from hydrocarbons, and thus produces lots of CO2. And if you think about it for a minute: Do CO2 emissions that occur miles away from where I'm standing right now really even exist?
- remram 2y agoJust give me an electric train for that distance...
- coryrc 2y agoIt makes better sense than curtailing solar or wind production. 50% is better than zero. That being said, hydrogen is usually the worst option, but I don't think that's true for every scenario.
- deleted 2y ago[deleted]
- jfengel 2y agoIf you had all of that H2, what is the additional cost to just fix some CO2 into hydrocarbons? It feels like that would be a much simpler way to get to net zero than having to reinvent all of the infrastructure. So much simpler that I wonder why anyone would keep trying on hydrogen. Which makes me darkly suspect that the goal is to take our attention off the solution that's already being deployed, i.e. wind and solar.
- skoocda 2y agoRegardless of net efficiency, that still entails collecting CO2 at a central facility (where it could have been dealt with in other ways, such as injection underground) and sprinkling it through the air as you fly over delicate ecosystems. I'm sure bankers see both as net zero, but condors might have more issues with your simpler workaround.
- JumpCrisscross 2y ago> sprinkling it through the air as you fly over delicate ecosystems I wouldn’t be so sure spraying water vapour is innocuous. As long as it’s atmospheric CO2, the environmental impact of synthetic fuels is much less than rebuilding the world’s air fleet and fuelling infrastructure to accommodate hydrogen.
- ianburrell 2y agoIt takes a lot of energy to pull CO2 from the air since it is only 400ppm. It also takes energy to make hydrocarbons. This means they will be really expensive. They might be used for classic cars but can’t replace fossil fuels. Hydrogen or ammonia have advantages that can be made from water and nitrogen. Ammonia may be good for ships and planes since can be liquid at cold temps. But can’t substitute in cars.
- rasz 2y ago>1 Kg of H2 stores about 33 kWh of energy as horrible as Hydrogen is, isnt that still ~two orders of magnitude better than li-ion? Pressure vessel will probably bring that down to one order of magnitude. In cars where weight doesnt matter that much Toyota, leader when it comes to pushing BS hydrogen, is only able to get Hydrogen Yaris to do 10-14 Fuji laps https://www.youtube.com/watch?v=DGL5g91KwLA https://www.youtube.com/watch?v=DGL5g91KwLA thats 45-60km of range on Hydrogen.
- skoocda 2y agoThat gravimetric energy density is about 2 orders of magnitude higher than lithium ion batteries.
- audunw 2y agoThe difference in volumetric energy density is not that big though, and hydrogen is not as flexible as jet fuel or even batteries when it comes to how you can store it in the vehicle. To be fair, high gravimetric density is a fairly large advantage for an air plane. But the bad volumetric energy density does present some serious challenges.
- dzhiurgis 2y agoSo why it’s not used in rockets?
- imtringued 2y agoIt was used in the Space Shuttle and SLS uses the same engine as the shuttle.
- ben_w 2y agoAlso nobody launches to orbit using lithium ion batteries as main propulsion.
- DarmokJalad1701 2y ago> Also nobody launches to orbit using lithium ion batteries as main propulsion. It can be part of the main propulsion. https://en.wikipedia.org/wiki/Rutherford_(rocket_engine) https://en.wikipedia.org/wiki/Rutherford_(rocket_engine) https://en.wikipedia.org/wiki/Electric-pump-fed_engine https://en.wikipedia.org/wiki/Electric-pump-fed_engine
- ben_w 2y agoThat's why I phrased it that way. Most internal combustion engine cars have a lead acid battery to start it up and run the spark plugs (or preheat the glow plugs if diesel). They don't get called "hybrid" or "battery powered" because the batteries aren't the propulsive power themselves. This is akin to that: the batteries run the pumps, they're not the propulsive system itself. Ion drives can be run off battery, but you can't launch with those.
- rich_sasha 2y agoBut according to HN armchair engineers, electricity will be free, nay, negatively priced in T+epsilon as exponential decrease in solar panel prices actually turns them negative. Or maybe even imaginary. THEN it definitely makes sense.
- more_corn 2y agoWholesome energy prices do in fact turn negative. But then you store it in batteries and use it when they flip positive again. No complicated, expensive, delicate, dangerous, cryogenic fuel systems required.
- ephbit 2y agoStoring it in batteries works for short periods of up to maybe a few days. You don't think there will be seasonal mismatch between renewable generation and electricity demand? Because if there _is_ a seasonal mismatch, hydrogen will be needed anyway.
- g8oz 2y agoEven 7 day storage will likely need hydrogen
- g8oz 2y agohttps://energy.economictimes.indiatimes.com/news/oil-and-gas/reliance-signs-up-with-norways-nel-for-hydrogen-electrolysers/110318084 https://energy.economictimes.indiatimes.com/news/oil-and-gas...
- ZeroGravitas 2y agoH2 doesn't make sense for a lot of things it's promoted for (see Michael Leibreich's Hydrogen Ladder for detail on this) but this is one area where it makes some kind of sense. https://www.linkedin.com/pulse/hydrogen-ladder-version-50-michael-liebreich https://www.linkedin.com/pulse/hydrogen-ladder-version-50-mi...
- chgs 2y agoThere are times it makes sense - when you have a remote location you need power in that is more than batteries can provide for example. Say you need 300kW in a farm miles from the nearest supply for 3 months.
- more_corn 2y agoWhy on earth would you want to maintain cryogenic fuel systems and delivery systems in a remote location?
- chgs 2y agoBecause you need power. And it’s not rocket science, it’s a shipping crate. The deliver system is a standard lorry, top it up with a can with some conpressed bottles in the back.
- _aavaa_ 2y agoIf you're delivering your electricity through hydrogen by lorry, you'll be cheaper just building out a transmission line. Or building 20x the number of solar panels so that you're good even on cloudy days.
- p51-remorse 2y agoFor three months? Maybe not. Getting right of way to run power lines is no joke.
- chgs 2y agoAs someone who has done this with both diesel and green hydrogen, no it’s not cheaper to run power, nor provide multi-megawatt solar provision