Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×
Science

Engineers Are Building Huge Salt Caves To Store Huge Amounts of Hydrogen (popularmechanics.com) 76

An anonymous reader quotes a report from Popular Mechanics: Scientists are going back to the salt mines, literally, to find a revolutionary new way to store large quantities of hydrogen for energy. Proponents say this could be a step toward unlocking hydrogen for renewables -- something that could change the energy landscape if it were resolved. "The project would initially have enough energy to power 150,000 households for one year and is scheduled to be operational by 2025," Fuel Cell Works reports. "It is being managed by Mitsubishi Hitachi Power Systems (MHPS), a maker of gas turbines, and Magnum Development, which owns salt caverns for liquid fuel storage." This works by basically repurposing existing, enormous caves to store reserves of hydrogen as well as other fuels.

Salt in particular makes a great medium for storing and then continuing to generate green hydrogen. CNBC explains how the caves are used to store and generate hydrogen: "Caverns can be created in salt domes by drilling into the salt dome and injecting the rock with water, which dissolves the salt. The resulting brine is extracted, leaving a large cavity. The next step is storing hydrogen in the cavern. Hydrogen electrolyzers can convert water into hydrogen by using renewable energy from solar and other sources. The hydrogen can then be stored, and reconverted to electricity when needed." Fuel Cell Works reports that while these caves are in the U.S., the major push for salt cave storage is in Europe.

This discussion has been archived. No new comments can be posted.

Engineers Are Building Huge Salt Caves To Store Huge Amounts of Hydrogen

Comments Filter:
  • by Joe_Dragon ( 2206452 ) on Monday November 30, 2020 @10:42PM (#60781004)

    oh the humanity!

  • Yes, hydrogen can be made using electrolysis. Yes, that electricity do the electrolysis can be from renewable source.

    But, as it stands today, 100% of the commercially usable hydrogen is derived from fossil fuels. It is far easier and profitable to sell the renewable electricity to the grid than to convert it into hydrogen and store in large caves.

    Even for long term ( months, not hours) energy storage, compressed air storage seems to be more viable and feasible than this hydrogen pipe dream.

    • There are some people storing energy in molten salt, but that is only considered viable in certain circumstances. There is some talk about converting to liquid air instead of compressed, which seems to be better than the molten salt.

      The main problem with selling back to the grid is that it has a hard limit of how much you can 'store' in the grid.

      • There are some people storing energy in molten salt

        Molten salt is used to store energy from thermal-solar [wikipedia.org].

        But existing solar thermal plants were built back when PV-solar was much more expensive than today. The plummeting price of PV panels has killed thermal-solar.

        The main problem with selling back to the grid is that it has a hard limit of how much you can 'store' in the grid.

        The transition to electric vehicles should fix that problem. EV chargers can be programmed to charge when available power peaks and prices fall. EVs with smart chargers can suck up a lot of energy.

        • Yep, I think hydrogen will surpass battery electronic vehicles in the mid term. it solves or improves on all of the problems we have with lithium based cells. weight? check. much more energy dense by weight and size then a lithium battery. can have a smaller tank on board, mounted higher due to less weight and away from impact zones. and tanks made to be blast resistant. none of this lithium under the whole floor of the car ready to catch fire when there is an intrusion from any angle. lpg has proven flami
          • No. Just simply no.

          • by drinkypoo ( 153816 ) <drink@hyperlogos.org> on Tuesday December 01, 2020 @09:09AM (#60781972) Homepage Journal

            I think hydrogen will surpass battery electronic vehicles in the mid term.

            Why?

            it solves or improves on all of the problems we have with lithium based cells.

            No, it doesn't. It also creates problems that batteries don't have.

            weight? check. much more energy dense by weight and size then a lithium battery.

            Sure, that's one of two problems it "solves". This is the only one it really addresses.

            can have a smaller tank on board, mounted higher due to less weight and away from impact zones.

            You can have a smaller tank, but you really can't mount it higher because you need to keep it out of the inside of the vehicle so that if it leaks, it doesn't leak inside. That also means you can't mount it away from the undercarriage impact zone.

            lpg has proven flamible gas cars can be safe.

            Not really [sciencedirect.com], at least, no safer than gasoline... which is not safe.

            but we've seen a lot lithium fires from electric car crashes while their numbers are still few on the road.

            We have NOT. There are many less vehicle fires per capita when compared to the usual standard, gasoline ICEVs. Further, virtually all of those fires have been the result of some gross insult to the battery, while gasoline ICEVs somewhat commonly burst into flames while parked, not even being used, and after zero impacts.

            charge time and network to deliver it? check.

            Uh no. The road network for hauling big dangerous expensive tanks of H2 around exists, but the fueling infrastructure does NOT. Also, the charge time is greater than gasoline, though less than an EV quick charge. However, you can charge your EV at home overnight, and the ranges are getting long enough to where the charge time is really a non-issue even for longer trips, so long as you can find a charger. That's still an issue in many places, but getting a hydrogen refill is impossible in all of them, so it's still a loss for hydrogen.

            similar to lpg, we can transport and fuel cars with gas now.

            Absolutely not. H2 has orders of magnitude higher requirements for transport and storage. It's more apt to compare it to CNG or LNG, which you can get almost nowhere, and which requires expensive tank recertification every five to ten years.

            it wont require much change to the existing fuel network.

            It requires entirely new filling stations and tanker trailers. You have to replace every part of the fuel network but the roads themselves, and the trucks that tow the trailers.

            cars are running on it now.

            A tiny handful of them.

            analasis of the viability all give it a pass

            anal asses what?

            environmental? check. no messy chemical processes, no controversial mining, no need to create and operate lithium recycling plants with chemical processing

            Efficiency of electrolytic production ~40%, environmental impact of current production is obscene since virtually all of it is currently steam reformed from natural gas, and current natural gas production is dependent on fracking.

            its very cost effective to have more PV output than an area requires

            That's true.

            and compress hydrogen in traditional tanks

            That's horseshit. The hydrogen tanks are special, and the compressors are even more special. They are expensive and most of the units we would need don't exist yet.

            then use it to run hydrogen engines for more traditional generation at night.

            Burning hydrogen in an engine is a true idiot move. Hydrogen is the perfect input for a fuel cell. Engine efficiency is piss-poor,

            • by Rei ( 128717 ) on Tuesday December 01, 2020 @09:28AM (#60782016) Homepage

              weight? check. much more energy dense by weight and size then a lithium battery.

              Sure, that's one of two problems it "solves". This is the only one it really addresses.

              Except that it actually doesn't.

              Honda Clarity FCV: 366mi EPA, 1875kg (not counting fuel)
              Toyota Mirai FCV: 312mi EPA, 1928kg (not counting fuel)
              Tesla Model 3 LR: 353mi EPA, 1847kg

              The notion that hydrogen vehicles go further is a myth. The combination of tanks, fuel cells, supporting hardware, and the buffering battery (which has to be of a variety that can take more / higher power cycles, e.g. less energy dense) works out to no advantage whatsoever. And it's only going to get much worse as EVs switch over to structural battery packs combined with Si or Li-metal anodes.

              Also, the charge time is greater than gasoline, though less than an EV quick charge.

              Actually, this isn't true either - fill times on hydrogen trucks take much of an hour, due to heating problems involved in dealing with highly compressed gases. They're working to bring it down with cooling systems, but they're not there yet. Crediting future hydrogen-filling tech to hydrogen without crediting future charging rates to EVs is of course a ridiculous comparison.

              Seriously, people, stop and look at this [hackaday.com]. This is Hyundai's fuel cell truck prototype. Look at all of those massive hydrogen tanks. Guess the range on that truck.

              Answer: 250 miles WLTP. Which would be something like 230 miles US.

              Hydrogen was always an absurd choice, and it keeps getting more absurd with every passing day.

              • You can fill a hydrogen pass car faster than you can recharge an EV pass car. That's still an advantage, although I would argue that it's largely irrelevant in the real world, and becoming less relevant over time. OTR trucks are special cases.

                • by Rei ( 128717 )

                  You can fill a hydrogen pass car faster than you can recharge an EV pass car.

                  Modern EVs have already passed the point where their range and charge time is beyond that of what most humans want / need in terms of stops on trips - e.g. the car waits for the person, not the other way around. And EV charge times only matter on road trips at all. At home, my charge time is "10 seconds" - 5 seconds to plug in, 5 seconds to unplug. Hydrogen vehicles have to detour to hydrogen stations in their daily lives.

                  I've

                • The hydrogen pumping stations are not as fast as gasoline pumps. It might take 20 minutes to service one vehicle, recharge and be ready to serve the next one. The number of pumping stations is so few, the wait time to get a pump also is significant. Compare the cost of expanding supercharger network to cost of expanding hydrogen pumping stations, it is not likely to catch up anytime soon.

                  Anyway the news item is not about hydrogen for transportation. Its for building so much renewable energy we make electr

            • Not really [sciencedirect.com], at least, no safer than gasoline... which is not safe.

              Do you often link to sources that don't say what you claim they say?

              while gasoline ICEVs somewhat commonly burst into flames while parked, not even being used, and after zero impacts.

              Is this some kind of troll? Or do you actually believe it's "somewhat common" for cars that are just sitting parked to burst into flames?

              There's less than 200K automobile fires per year in the US. There's around 280 MILLION cars on the road.

              "somewhat common". I do not think it means what you think it means.

              • It's common enough to where it happens regularly, and it's more common than EVs combusting without some good reason why.

                The real problem with EVs, and their batteries in particular, is their ability to burst into flames well after the original impact. Lots of research is going into alternate forms of electrolyte which will reduce or hopefully even eliminate this problem.

            • while gasoline ICEVs somewhat commonly burst into flames while parked, not even being used, and after zero impacts.

              Upon seeing this sentence, I put down my smartphone, got out of bed and walked to my computer just to say: you, sir, are completely and totally full of shit.

          • by MachineShedFred ( 621896 ) on Tuesday December 01, 2020 @09:47AM (#60782068) Journal

            1. You hear about EV fires because someone wants you to hear about EV fires. In comparison to standard combustible fuel vehicle fires, there's so few as to be wholly unremarkable [wikipedia.org] unless there's an agenda. Then have a look at the 171,500 vehicle fires in the US alone, from the years of 2014-2016 [fema.gov] in comparison. Even adjusting for only having 1% or so of the vehicles on the road being EVs in 2016, there would still be an expected 1,715 fires from EVs during those two years if the rate at which vehicle fires were the same regardless of power plant.

            That rate absolutely is not the same, because there haven't been 1,715 EV fires in total, for all time. Conclusion: anyone pointing to lithium fires as a reason to not use batteries in vehicles is a useful idiot for the traditional automotive industry, spreading their FUD for them. As it turns out, carrying around a tank of highly combustible hydrocarbons is more dangerous than a reactive solid metal that can be encased in armor that never needs to be opened.

            2. Try using the enter key every once in a while. It makes it so much nicer for the reader.

            3. Where do you think hydrogen comes from? Nearly 100% of commercially available hydrogen comes from controversial mining and messy chemical processes - namely oil drilling and hydrocarbon cracking.

            4. How do you expect all the infrastructure necessary for transporting, storing, and transferring hydrogen to come into existence? Here's a hint: you can't just re-use existing gasoline and diesel infrastructure. As it turns out, different materials have different storage and pumping needs. For example, liquid petroleum products stay liquid when exposed to open air (for the most part) so you don't need to build pressure vessels to store them in. Transporting hydrogen isn't anywhere the same as transporting other petroleum products. Oh, then there's hydrogen embrittlement [wikipedia.org] to deal with, which means that whatever infrastructure you are using to transport and store the hydrogen has a useable life before it ruptures and (in the best case) leaks out all your hydrogen. Which means you get to rebuild it all after some period of years.

            Hydrogen is not the utopia you seem to think it is. It's expensive, it still relies on oil. It's still dangerous. And the infrastructure doesn't exist for it to be used at scale. And even if it did, you'd still have to rebuild it again, and again, and again.

          • Nope. Costs way more to use hydrogen than plain old BEV. Why, because you have to reinvent the entire infrastructure to extract, produce, and store hydrogen, just to convert it to back to electricity in the first place. We already have an electrical grid, so going to wind/solar/nuclear -> grid > car battery be far more economical than mining natural gas, splitting hyrdrogen / CO2, compressing hydrogen, dumping CO2 into atmosphere, transporting hydrogen (read issues on storing hydrogen) and then
    • Re: (Score:3, Insightful)

      by oddtodd ( 125924 )

      >> as it stands today, 100% of the commercially usable hydrogen is derived from fossil fuels.

      Since nothing ever changes this will always be true.

      • by ShanghaiBill ( 739463 ) on Tuesday December 01, 2020 @02:06AM (#60781286)

        You are missing the point. There is a commercial demand for hydrogen and that demand is currently met by steam reforming of natural gas, which creates a lot of CO2.

        So if there is surplus electricity, we should be using it for hydrolysis to meet this commercial demand rather than (very inefficiently) shoving it down into a salt mine.

        The project described in TFA makes no economic sense. The only plausible explanation is that it is being driven by politics and funded with taxes, so nobody cares if it makes sense.

        • I don't think it is supposed to make economic sense right now.

          One of the main problems with solar and wind energy is we have little control over the supply. The sun shines when it shines, and the wind blows when it blows. As more and more comes on line, we are either going to face wildly changing electricity prices (miniute-by-minute) as we try and force demand to match supply, or we need a big increase in storage capability. About the only proven storage technology at the right scale that we have at the mo

          • Australia already has at least three sites with battery storage operational and a years' worth of data on two of them. We're past the small scale tests of batteries and they are proving themselves in the field.

            https://www.energy-storage.new... [energy-storage.news]

          • I don't think it is supposed to make economic sense right now.

            So what good is it?

            One of the main problems with solar and wind energy is we have little control over the supply.

            Yes yes, we aren't new here. We know how this works. However, you don't. When you're talking about the scale of whole nations, the wind is always blowing somewhere. We have substantial control over the wind supply by simply building turbines in enough locations that the wind is always driving some of them.

            For many of the possible technologies, especially batteries, we can probably make a fair estimate of how well they will work form small scale tests. But for others, such as underground compressed air strorage and and hyrdogen storage, we won't really know all the problems they might face until we try it out.

            We've been trying out compressed air storage. It's actually already more efficient than dicking around with hydrogen, and the requirements are simpler and cheaper. Putting hydrogen in sa

            • I don't think it is supposed to make economic sense right now.

              So what good is it?

              One of the main problems with solar and wind energy is we have little control over the supply.

              Yes yes, we aren't new here. We know how this works. However, you don't. When you're talking about the scale of whole nations, the wind is always blowing somewhere. We have substantial control over the wind supply by simply building turbines in enough locations that the wind is always driving some of them.

              There are actually places where the wind doesn't stop blowing. near where I live, the Allegheny front escarpment is home to constant wind. So we build a lot of turbines, and we have peaking power, and spares. That's the cool part. You can build incrementally, and the cost of placing a couple wind turbines pales next to building a new natgas plant.

              For many of the possible technologies, especially batteries, we can probably make a fair estimate of how well they will work form small scale tests. But for others, such as underground compressed air strorage and and hyrdogen storage, we won't really know all the problems they might face until we try it out.

              Leaks. I'm not against trying some experiments, but they need to be in an unoccupied area. In addition, the very lightness of hydrogen might be an issue. I need to

              • Yes, I'd love to put a fully mechanical version of my diesel with an air starter into my bus, which currently has a 1999 ISC (there are air starters for Cummins 8.3, because it is venerable and has seen much marine duty, including naval use.) But I'd also need to figure out an air- or hydraulic-driven fuel pump to be fully electrical system failure-proof like my 1982 Mercedes 300SD. I lost all power once and was still able to finish driving to work.

                • The old pure bred mechanical engineers hated electricity. Cant blame them, old lead-acids were very finicky and some short happens somewhere and they find it difficult to diagnose and fix the electrical faults.

                  But unless you start with a design goal, "no electricity use at all" and be willing to pay for the higher cost, it is nearly impossible to have a purely mechanical ICE. At the very least there will be a magneto for gasoline engines.

                  Diesel fuel is self igniting, they dont need spark plugs. So they

                  • I enjoy electricity, but I also enjoy simplicity.

                    I like a mechanical diesel with electrical gauges.

                    Right now all our vehicles are diesels. 1982 Mercedes 300SD OM617, 1999 Blue Bird Q-Bus ISC 250, 2006 Mercedes Sprinter OM647. The Sprinter is HPCR and fully electronic. The bus has unit injection but it also has accelerator by wire, and lots of other electronic management (low oil pressure kill switch, etc.) The 300SD is fully mechanical with electric gauges, even the 4 speed slush box is controlled by vacuum

          • > As more and more comes on line, we are either going to face wildly changing electricity prices (miniute-by-minute) as we try and force demand to match supply, or we need a big increase in storage capability. There's no reason this can't be done - some consumers will put up resistance to it, but it's getting to the point where it's really easy to manipulate your home energy use. Car chargers are a great place to start - right now mine just charges when it's plugged in because the power cost (to me) is
      • So vastly increasing the usage of hydrogen means we're not going to continue using and scaling the cheapest and most well understood source of hydrogen we have available?

    • And yet, one of the repeated criticism towards solar and Hydrogen is that the Sun doesn't always shine and the wind doesn't always blow.

      Yes, most of the hydrogen used commercially is derived from fossil fuel, but that is for convenience. No one is stupid enought to create hydrogen from fossil fuels and store it into a cave for later use. It is far easier and profitable to use fossil fuel without the conversion in the first place.

      This is obviously an avenue to make more power available from renewable
      • And yet, one of the repeated criticism towards solar and Hydrogen is that the Sun doesn't always shine and the wind doesn't always blow.

        That's why it's a good idea to be able to store electricity...

        • by sfcat ( 872532 )

          And yet, one of the repeated criticism towards solar and Hydrogen is that the Sun doesn't always shine and the wind doesn't always blow.

          That's why it's a good idea to be able to store electricity...

          So electrolysis is 80% efficient and a fuel cell is 40-60% efficient. So best case your "battery" is 48% efficient which means you need a 96% change in power costs to breakeven. Good news is that the CA grid is so unstable due to all the wind (and the fact they are trying to shutdown the nuclear plant) that the daily swing in prices is more like 350%. Bad news is that's localized to CA mostly, energy price swings are not usually so large and not something you can count on in most places or in the future.

          • "Also, you can make H2 from nuclear far more easily (and cheaply) if a reactor was designed to make it. "

            What?
            • The reactors in Fukushima certainly seemed to be very capable of producing hydrogen. Enough to blow the roof off.

            • Solid oxide electrolysis. Requires high temperatures and electricity, which a nuclear reactor can definitely provide in a far cleaner way than basically anything else.

              Also, basically every reactor that uses zirconium-clad fuel elements (which is essentially all of them) will create some amount of hydrogen during normal operation of the reactor, which is captured from the coolant because you don't want gaseous voids in your coolant - it will slow down reactivity in most reactor designs, or speed up reactivi

              • Ok, but the 500C hardly justifies a nuclear reactor as most kitchen ovens are just below that. I'm not sure why it is cleaner than wind though, and if it is easier I would like to hear of any real implementation that demonstrates that. Just the red tape involved for anything nuclear pretty much nulls the concept of 'easy', and it is only cleaner if we treat nuclear waste as an externality.
                • Sure you can use a kitchen oven on broil, but you won't be able to create the volume necessary. As it turns out, it takes a shitload of heat to create a shitload of heated water.

                  If you want to do an experiment, you can do it on the tabletop with an induction heater. If you want to scale it to an industrial process, you need something inherently scalable. Extra points if you are using a waste product of energy generation (heat) in order to do it.

                  So which would you like to do? Use wind capacity that could

                  • I do not think the intent is to use wind capacity that could be powering other things though, but to store that capapacity when demand is low.

                    Thanks for taking the time to explain; scale is the important factor.
                • by sfcat ( 872532 )

                  Ok, but the 500C hardly justifies a nuclear reactor as most kitchen ovens are just below that. I'm not sure why it is cleaner than wind though, and if it is easier I would like to hear of any real implementation that demonstrates that. Just the red tape involved for anything nuclear pretty much nulls the concept of 'easy', and it is only cleaner if we treat nuclear waste as an externality.

                  You are confusing F and C. Your stove can do 500F, but certainly not 500C (which is ~900F). There are several chemistries you can use above 500C to make H2. And a single wind turbine requires 1 metric tonne of rare earths per 12MW tower. Wind is anything but clean.

                  • Mixing C/F was a silly mistake but hardly makes a difference. As demonstrated by Faraday, a standard domestic candle flame has zones ranging between 600C and 1200C. These are not temperatures difficult to achieve.

                    I am all for nuclear energy if done right, but how does the amount of rare earth required for a wind mill compare to mining uranium. Most importantly, that is for the initial building. Considering maintenance and the management of nuclear waste I am not quite sold on clean, and even less on
                    • by sfcat ( 872532 )

                      Mixing C/F was a silly mistake but hardly makes a difference. As demonstrated by Faraday, a standard domestic candle flame has zones ranging between 600C and 1200C. These are not temperatures difficult to achieve.

                      They are difficult at industrial scale. 500C is in between lower heat which is easy to transfer by boiling water and higher temperatures which are easy to do with natural gas. Stepping down the heat causes inefficiencies that are difficult to overcome.

                      I am all for nuclear energy if done right, but how does the amount of rare earth required for a wind mill compare to mining uranium. Most importantly, that is for the initial building. Considering maintenance and the management of nuclear waste I am not quite sold on clean, and even less on 'easy'.

                      It compares quite well as 1 tonne of U makes many GW of power all the time and that 1 tonne of rare earths makes 12 MW about 10% of the time. Plus most engineers want to use Th as its already mined not that it matters as LEU is very cheap.

                    • Ok - thanks for taking the time to explain.
    • Why do you keep parroting that RETARDED oil industry talking point?

      We're using dams, wind and solar power to electrolyze water into oxygen and hydrogen right now!

      How is "We've done it like this in the past, and if I ignore hard enough, we're still doing '100%' like this right now." even an argument to you?
      *Obvioulsy* we are not doing it like this in the future. Hell, look at the actual statistics on renewable power usage right now in countries that do not live in the past!
      I presume you perfectly knew this,

    • But, as it stands today, 100% of the commercially usable hydrogen is derived from fossil fuels. It is far easier and profitable to sell the renewable electricity to the grid than to convert it into hydrogen and store in large caves.

      Presumably it's the owners of "the grid" that will be building these - so they can pay less to the sellers at peak times.

    • by guruevi ( 827432 )

      Yeah, but hydrogen is clean energy, that's all that matters. Solar panels have similar issues, they cost way more to the environment between fossil fuels and heavy metal mining and recycling than they will ever reduce (sure if they survive for 25 years and cost nothing to maintain, but many are already being replaced less than a decade after installation because higher yield versions and subsidies promote recycling them asap).

      Even these salt mines are incredibly, incredibly environmentally damaging. To diss

  • by redelm ( 54142 ) on Monday November 30, 2020 @10:57PM (#60781030) Homepage

    Salt caverns (tubes really) are not new. They were made by solution-mining salt for chlor-alkali plant feedstock. The left-over cavern (full of brine, please) is typically 10m diameter and 50m long. When reused, they are most often used for LPG (butane/propane) or crude oil. The United States Strategic Petroleum Reserve is mostly stored in these salt caverns all along the US Gulf coast, mostly Louisiana. The oil inside floats on the brine at the bottom and is removed by backfilling with brine. Hydrogen could be used if it doesn't leak out the dome or pipestring too fast and is available at the right pressure to maintain cavern integrity.

    The biggest problem is finding suitable locations with salt formations near hydrogen producers and consumers. Both Hydrogen and electricity can be moved 100s of kilometers but not 1000s easily.

    • The biggest problem is finding suitable locations with salt formations near hydrogen producers and consumers.

      Yep and the article states exactly that:

      ...while these caves are in the U.S., the major push for salt cave storage is in Europe.

      That's a wee bit of a problem.

  • Will this actually work? I thought that hydrogen, being a small, simple atom, had a tendency to leak out of storage containers.
    • Re: (Score:2, Insightful)

      Will this actually work? I thought that hydrogen, being a small, simple atom, had a tendency to leak out of storage containers.

      Yep. There will be some loss through escape.
      Then there is the conversion loss of separating it from its source (water or oil).
      Then there is the conversion loss when you use it in a fuel cell.
      Then there is the conversion loss putting the resulting energy through an inverter to drive a motor.

      After all that, it turns out to be more expensive per mile than petrol.

      • by BAReFO0t ( 6240524 ) on Tuesday December 01, 2020 @02:06AM (#60781288)

        And that's completely missing the point.

        Petrol runs out. Petrol literally ruins the planet and kills us all to death. And I mean all ... species.

        End of story.

        Plus, for overkill, there's way more solar energy than we can use up anytime soon. So lets talk about efficiency once we start using up *the sun*, alright?

        Storing it on hydrogen is stupid IMHO. We've got highly efficient CO2 capture now. Make some methane. Burn it cleanly in a fuel cell. Capture the resulting CO2 again. Closed cycle. Even wrap it in a box and call it a battery. There, problems solved.

        • by TechyImmigrant ( 175943 ) on Tuesday December 01, 2020 @02:45AM (#60781350) Homepage Journal

          I agree with this. Storing in hydrogen is pretty stupid. There are better means of storing energy. Biofuels are essentially solar power sources since the plants are converting solar energy to chemical energy and drawing the co2 from the atmosphere. Synthetic fuels made using electricity from renewable sources are also fine.

          The primary way to end the increase of carbon in the atmosphere is to stop digging and drilling it out of the ground, so all carbon we emit comes from surface sources, so the carbon in the atmosphere doesn't increase.

          In terms of photovoltaic cells, they are not super efficient, but we have plenty of land and sea on which to put such cells, so it's not a bad way to generate storable energy, or to supplement the grid during high demand times of day, while the sun is shining and the A/C units are all running.

          My point about hydrogen being more expensive than petrol was that it doesn't lead to people switching to hydrogen cars when they are more expensive to buy and more expensive to run. However battery electric cars are much cheaper to run and not hugely more expensive than ICE cars and they work much better. I own a Leaf and a Tesla and they are both much better than equivalent ICE cars and both cheaper to run.

          • The problem with biofuels is that they still make soot, and a meaningful soot filter is the size of a tractor trailer. DPFs only catch big funky chunky soot that isn't particularly hazardous anyway, as it's larger than cilia and can easily be removed from the lungs. When they regen burn to clean themselves they do turn some of that soot into CO2, but they also turn some of it into PM2.5 soot which is extremely harmful to life, being smaller than cilia, and thus persistent in the lungs — persistent car

    • As well as the leak problem, hydrogen also has an extremely poor energy density, when stored at atmospheric pressure. I believe practical hydrogen storage tanks operate at a pressure of around 750 bar (I do not have the data to hand). I can't see underground caverns being operated at anything much above atmospheric pressure.

      • "I can't see underground caverns being operated at anything much above atmospheric pressure."

        Of course you can't see it, the storage is underground and hydrogen is invisible. ;-)

        But seriously, salt caver storage runs at 70-200 ties atmospheric pressure. There's antually a *minimum* pressure to keep the cavern from closing. https://www.popularmechanics.c... [popularmechanics.com]

        • Oops, wrong link: https://medium.com/@cH2ange/lo... [medium.com]

        • But seriously, salt caver storage runs at 70-200 ties atmospheric pressure.

          That is very interesting. There is however a major difference between storing gas at high pressure, and liquid at high pressure. A gas is compressible, a liquid much less so. This means that compressed gas stores an enormous amount of energy, like a spring. If a compressed gas vessel ruptures, there is an explosion. A break in a compressed liquid system, e.g. hydraulics, is far less dangerous. As far as I know, pressure vessels are proof tested using liquid pressure rather than gas, for safety reasons.

          I am

  • by CHduckie ( 7347722 ) on Monday November 30, 2020 @11:30PM (#60781096)
    "I'm Cave Johnson. I own the place."
  • The hydrogen has to come from somewhere. As TFA says, it has to be generated somehow before it can be stored, which makes the salt caves a huge battery, not a way to create energy. They're talking about splitting water with solar and other undefined sources. Ok fine, but hydrogen is notoriously difficult to contain, implying significant losses, and even liquified hydrogen has significantly less energy than petroleum, which means shipping it to places that can use it for energy isn't as cost effective.

    Sto

  • The fine articles have energy in household-years and volume in Willis towers.

  • It's hyrogen after all. Fits through all the molecule gaps.

    They just don't care.

    • You can store hydrogen without a problem in a steel cylinder. Hell, you can even store it for a few days with the thin walls of a blimp [wikipedia.org]. What makes you think that hydrogen is going to diffuse through a few meters of salt and rock more than it diffuses through the walls of a storage tank? Any loss is going to be miniscule, especially compared to inefficiencies in making the hydrogen in the first place.

      • Big problems! And you even answer your own statement. The point is storing hydrogen in things NOT a steel cylinder is extremely problematic. Even with modern materials, a cubic meter gas bladder suspending weight didn't last two weeks. Your mentioning blimps with "a few days" already shows an unacceptable rate of loss. Stuffing hydrogen underground in rock and salt will have it leaking like a sieve.

        • oh forgot to put link of airship dudes and their experiments. I'm all for hydrogen in airships by the way, with proper design and topping off the tank every few days there is no problem. Much different than energy storage issue with leakage.

          https://www.eucass.eu/doi/EUCA... [eucass.eu]

  • There should be some law that forbids using the word 'huge' twice in the same sentence.

  • If something goes wrong.... they'll be fracking at an unprecedented level... :)
  • "Hydrogen has a very broad flammability range—a 4 percent to 74 percent concentration in air."

Real Programmers think better when playing Adventure or Rogue.

Working...