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Power Data Storage Science Technology

Scientists Propose Using Mountains To Build a New Type of Battery For Long-Term Energy Storage (ieee.org) 200

An anonymous reader quotes a report from IEEE Spectrum: One of the big challenges of making 100 percent renewable energy a reality is long-term storage," says Julian Hunt, an engineering scientist at the International Institute for Applied Systems Analysis in Austria. Hunt and his collaborators have devised a novel system to complement lithium-ion battery use for energy storage over the long run: Mountain Gravity Energy Storage, or MGES for short. Similar to hydroelectric power, MGES involves storing material at elevation to produce gravitational energy. The energy is recovered when the stored material falls and turns turbines to generate electricity. The group describes its system in a paper published November 6 in Energy.

"Instead of building a dam, we propose building a big sand or gravel reservoir," explains Hunt. The key to MGES lies in finding two mountaintop sites that have a suitable difference in elevation -- 1,000 meters is ideal. "The greater the height difference, the cheaper the technology," he says. The sites will look similar, with each comprised of a mine-like station to store the sand or gravel, and a filling station directly below it. Valves release the material into waiting vessels, which are then transported via cranes and motor-run cables to the upper site. There, the sand or gravel is stored -- for weeks, months, or even years -- until it's ready to be used. When the material is moved back down the mountain, that stored gravitational energy is released and converted into electrical energy.
Not only is the system more environmentally friendly than pumped-storage hydropower and dams, but it's more flexible to meet varying energy demands.

"Hunt estimates that the annual cost of storing energy via this system will vary between $50 to $100 per megawatt hour (MWh)," the report adds. "And he says that the energy expended to transport materials to the upper sits will be offset by the amount of gravitational energy the system produces."
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Scientists Propose Using Mountains To Build a New Type of Battery For Long-Term Energy Storage

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  • improvement (Score:5, Funny)

    by religionofpeas ( 4511805 ) on Saturday December 07, 2019 @09:04AM (#59494822)

    Instead of rocks and gravel, hoist charged lithium batteries for extra power.

  • Re: (Score:2, Flamebait)

    Comment removed based on user account deletion
    • Re: (Score:3, Funny)

      by Joce640k ( 829181 )

      It's not stated yet but I hope they plan it so they use two mountain ranges, one on either side of the planet.

      If they raise up that much material on just one side it could push the planet out of orbit.

    • In fairness, hydropower storage and generation have always been considered "green". But they aren't and are very destructive to the ecosystem.

      • To a tiny local ecosystem. Raising that up in importance was a bad decision.

        If this is such a global emergency, you should not raise its importance above that.

      • Pumped hydro and this scheme use relatively little area compared to normal hydro because of the far greater height difference.

        Anything we do has footprint. In the big scheme of things this is hardly relevant.

        This is an interesting alternative to seawater PHES, both are available in orders of magnitude greater amounts than necessary to cross a couple months of extreme winter weather in most places. Just depends which is cheaper.

      • Even if you're using existing reservoirs?
        I don't think anybody is talking about creating new reservoirs just for pumped hydro.
        Here are the dates of construction for the largest hydro plants in the US:

        1 Grand Coulee 6,809 1942/1980
        2 Bath County PSP 3,003 1985
        3 Chief Joseph Dam 2,620 1958/73/79
        4 Robert Moses Niagara Power Plant 2,515 1961
        5 John Day Dam 2,160 1949
        6 Hoover Dam 2,080 1936/1961
        7 The Dalles Dam 2,038 1957

        • None of these have anything to do with "pumped hydro storage". They are just reservoirs with hydroelectric dams.

        • by grumling ( 94709 )

          Why would you pump water up into a reservoir? How about just closing off the penstocks?

      • But they aren't and are very destructive to the ecosystem.
        No it does not. It just changes a valley ecosystem with no lake into a valley ecosystem with a lake. Last time I checked lakes were still nice and adorable ecosystems. And you can even use them for recreation aka fishing, or sailing. Sometimes I hear that tourism suddenly is a business around such lakes, or hotels offer local fish.

        But well, what do I know, I live half of my life in yahoo Germany - or Paris - and the other part in a in fact really ya

        • But well, what do I know, I live half of my life in yahoo Germany - or Paris - and the other part in a in fact really yahoo (full with lakes!) area in Thailand.

          Sorry, but your opinion is based on your direct experience with actual lakes in the real world, and should therefore be ignored in favor of the people here who are just talking out of their butt.

    • How is moving around a rock inside of a mountain destroying the environment? Nothing lives there! Nothing affects it!

      No, I did not even read TFS, as I'm sure your reaction means somebody came up with the most boneheaded perversion of what I mentioned here.
      But my point: I immediately thought of what I wrote here, and so should you!

    • ?? Isn't this what we been doing with every form of energy generation... since the dawn of?

    • > So which mountain range will be offered to feed the green madness?

      All of them, if you plan to power the United States during December, or during hurricane season. I don't think people appreciate the amount of power a country like the United States needs. Lake Mead, begin Hoover dam, flooded 247 square miles. Those 32.236 km3 of water can provide enough power to run the western US for a couple minutes.

      Remember if we want to get rid of fossil fuels such as gasoline, we need to triple our electri

      • Those 32.236 km3 of water can provide enough power to run the western US for a couple minutes.

        Didn't do any math on this I see. Hoover Dam discharges 11 km3 of water a year (9 million acre feet is the unit commonly used) and produces 0.1% of all the U.S. annual electricity consumption (4 terawatt hours, not too bad for a single installation). Since there are 525960 minutes in an average year that is about 526 minutes of power for the entire country (not just the western US) using only 1/3 of Lake Mead's volume. The full volume is thus about 1600 minutes, and the wetern U.S. has about 1/4 of the US p

  • Dropping 1 ton/second down 1000 meters is only 9 MW of output power. That's useless.

    • it's stupid because storing energy in hydro is better in every possible way, efficiency included. just pump the water into the artificial lake. proven technology, it works, it has been used for decades.

      also didn't we see this proposal earlier this year already?

      these scientist probably even know the idea is dumb. that's the sad part. just trying to eke out a living with alternate stupid ideas.

      • The technology has been in use for at least thousands of years - elevators and pulley systems have used weights to store energy.

        Specifically as a storage of energy, this system has also been used using train cars up a hill that then slowly descend generating energy.

        The problem is maintenance and density, it can't store very much energy even if you used lead (sand and gravel aren't dense enough) and the mechanical parts require tons of maintenance, especially when standing still.

        • Its only real advantage over water is no evaporation, as mechanical wear and tear will be worse than water pumps.

          Efficiency differences are of low importance if the energy is renewable like wind and solar, also "free" after construction. So would evaporation be bad? There's also those "silly balls" covering the lake to reduce evaporation.

          Their one advantage may not be so great and offset all the disadvantages.

        • Another problem is complicated movements in both storage areas. If you have a lake full of water, you can drain it through a single hole at the lowest point. You can't do that with a pile of concrete blocks. Blocks have to be picked up, transported, and released with many degrees of freedom, and you have to deal with lots of little things that could go wrong, like chipped blocks, broken cables, or stuck grippers. On top of that, the blocks would need to be moved at great speed to get a useful amount of pow

          • On top of that, the blocks would need to be moved at great speed to get a useful amount of power.
            The speed is close to irrelevant.

            After all you can have many "lines going downhill".

            Most likely you will have a kind of ropebelt or cable car design.

            Such a plant could simply provide base load and let another plant react on fluctuating load.

            • The speed is close to irrelevant.

              As I said earlier, moving 1 ton/second only gets you about 9 MW of power. So speed is very relevant. And 1 ton/second is already quite fast for a crane moving concrete blocks.

              Most likely you will have a kind of ropebelt or cable car design.

              You still need a storage area for the blocks, and cranes to move the blocks from storage into the cable car.

              • You still need a storage area for the blocks, and cranes to move the blocks from storage into the cable car.
                No you don't. Think about a lorry ... when it is at its place, it just tilts sideways and dumps its load, which can roll downhill a few more meters.

                The filling might be more problematic, but I guess a ropebelt conveyor, with a rotating shovel at the end, can do that quite nicely and quickly, too.

                • And then just dump everything on a pile, or what ?

                  According to engineers, this is a plan for "long term storage". I'm not sure what exactly they mean by long term, but let's say 100 MW generating power (which is still very small) for 4 weeks straight. That means you have to be able to load 15 tons of material per second (about 6 cubic meters), and a storage of 40 million tons.

                  I don't think you can pick up 40 million tons of concrete/gravel or whatever with a rotating shovel and a conveyor belt. That's a cub

        • The problem is maintenance and density, it can't store very much energy even if you used lead (sand and gravel aren't dense enough)

          No problem- use depleted uranium. 1.67 times as dense as lead.

          Or you could use tungsten or gold. Even better, go to the max and use osmium or iridium. (Mountains of any of those things would be a bit spendy, but it's only taxpayer money.)

      • by fazig ( 2909523 )
        I'd bet that we've seen similar proposals before. Potential energy is not a new concept.

        Hydro storage is better in many ways, I agree. However you can only store potential energy in water if that water isn't too far away from you. And while you certainly could use some centralized storage that is hundreds of miles away, transmission losses will have to be taken into consideration as well.
        The usual ideas to approach a solution for this problem was to replace the mass of water with the mass of readily avai
      • For the record: I supported your suggestion until just some minutes ago.

        Th problem with that was always evaporation, ruining nature in that valley, and even tectonic problems proportional to its size.
        Even if you cover it and put it into an already ruined area it is u
        ruining a huge are of land.

        Using a "rock elevator in a mountain" model completely eleminates all environmental impact. Done right, even the tectonic one.

        Water also brings in a load of maintenance on the turbines and such, cleaning the lake, and

      • But hydro isn't "better in every way". Please consider the following:

        1) Hydro is in limited places. A mountain range isn't enough. Nor is adding in a river. You also need to consider the soil of the foundations, retention area, etc. Not to mention the loss of a valley of an ecosystem and downstream impacts.

        2) All hydro have limits such as the ranges of water retention they can have. How much power it can absorb and release. And these vary by season and between years.

        3) Then there is the losses. Transmiss

      • Pulling a train up with sand has the same efficiency, probably even a bit better, than pumping water.
        So, the question is how efficient can the stuff be loaded on "trains" or put into "elevators" and stored at both endpoints.

        The idea is not dumb, you are dumb.

  • This idea has already been busted by thunderf00t .. https://youtu.be/NIhCuzxNvv0 [youtu.be]
    • by v1 ( 525388 )

      It will always be more efficient to move water up a gradient with pumps and generate power with hydro. As an added bonus, RAIN can charge your system for free. We've been running solely on the latter for decades. If they wanted to be useful they should have pioneered a good way to pump water back into the reservoir. But any energy producing system you place at that location (like wind turbines) would probably be better served to just add to the power the hydroelectric dam is already producing. ANY meth

      • Water isn't as dense as gravel, nor is it in abundance, nor does it rain everywhere; less so at the top of mountains. Gravel can be found on site.

        Our grid needs more storage. Our production varies over time and our consumption varies over time. Today we inefficiently shutdown power plants, throttle their outputs, have brown outs, dump energy, and have on demand plants to help match consumption. With renewables, that variability increases.

        So we need more capability to shift excess production to excess cons

  • by aurispector ( 530273 ) on Saturday December 07, 2019 @09:22AM (#59494846)

    Is this what passes for science these days? So much derp it's hard to know where to start. First, it doesn't "store gravitational energy" it stores kinetic energy. The amount of equipment and energy it takes to move sand or gravel around, merely owing to the fact that it's sand/gravel and not water is huge. The reason we use water in hydroelectric power generation is because it is easy, relatively cheap and clean to move around - all you need are pumps, pipes and cisterns. For sand and gravel it's not so easy. Additionally, sand and gravel will degrade to dust, the very fine kind that gets into everything mechanical and destroys it, like the equipment you will need to move it around in the first place.

    This sounds like the kind of feel good scam somebody is using to get a fat government contract. Solyndra 2 anyone? Who's getting rich?

    Nuclear energy is the only proven non-CO2 emitting technology available to fill the gap.

    • Re: (Score:3, Insightful)

      It does store gravitational potential energy, not kinetic energy. A flywheel stores kinetic energy, i.e. it stays in motion until you convert its kinetic energy into something else. The gravel is not in motion (relative to the machine) when it's stored at the upper site, hence it has no kinetic energy. Can't the nuclear industry afford shills which can tell kinetic and potential energy apart?
      • And it's gravitational since that's how it was stored and will be reclaimed, back to kinetic energy. (As opposed to storing potential energy in a coiled spring.)

        "And he says that the energy expended to transport materials to the upper sits will be offset by the amount of gravitational energy the system produces."

        This statement is off. It sounds like he's covering for an objection, "What about the energy spent to get it up there?" The answer should have been, "The energy expended to transport up the mountain is the energy being stored."

    • Water is a scarcity. Water evaporates and leaks out. Water rusts things. Hydro isn't any less maintenance. New ones will have massive environmental impacts.

      We use hydro because we found a rare and suitable site, that has enough average generation capacity to make it worth the investment, and is worth the impact to the valley and downstream systems. Not because it is "easy".

    • by AmiMoJo ( 196126 )

      It doesn't store kinetic energy. You are thinking of a flywheel. It stores potential energy.

      This illustrates why the scientists, who doubtless know that the correct term is potential energy, chose to say "gravitational energy" for the sake of laypeople such as yourself who won't understand the scientific terminology. It's pretty pointless announcing your great idea if no-one actually understands it.

      There are advantages to moving solid or semi-solid objects instead of water. Water evaporates over time, it le

      • Very long term storage doesn't seem to be needed, only short term.

        It would be nice if we can store summer energy for the winter, especially in places like Northern Europe.

        • by AmiMoJo ( 196126 )

          I haven't done the numbers but I'd guess it's cheaper to just install more capacity than it is to try and store energy long term.

          • It's not just about price but also about feasibility. I could cover my entire roof with PV solar and get more than enough power in the summer, but almost nothing on gray winter days when I need the most.

            • In northern Germany*, you can expect about 1/7th of the energy return from solar panels in November compared to June. This includes all effects, for example the weather, the shorter days and the lower insolation angle during the winter months. You need about seven times the peak capacity compared to the summer months if you want to get by with just solar and no long term storage. In practice, solar combines well with wind energy and the winter months are windier. If you only rely on solar for half your elec
            • by AmiMoJo ( 196126 )

              But unless you have two mountains in your back yard this doesn't sound like a very practical solution. In fact no kind of storage is practical if you want to store your solar PV harvested energy for 6 months.

              This is for grid scale. At that scale you add more capacity to cover the winter... Or rather the summer, because there is more wind in the winter in many places.

              • I don't think this is a practical solution for anything. Moving sand and rocks up a mountain doesn't scale well enough to solve any practical problem.

        • by amorsen ( 7485 ) <benny+slashdot@amorsen.dk> on Saturday December 07, 2019 @12:57PM (#59495318)

          It would be nice if we can store summer energy for the winter, especially in places like Northern Europe.

          In Northern Europe, wind power is more abundant in winter. It is reasonably cheap to build enough wind turbines to cover the electricity needs of winter. This will almost certainly happen over the next decade.

          Then the problem is reduced to storing energy for a few weeks, not for 6 months. It is still a large challenge, especially with so much new electricity demand being added, but it is an order of magnitude easier than summer-to-winter.

          • It is reasonably cheap to build enough wind turbines to cover the electricity needs of winter.

            We still need energy for heating, cooking, transportation and industry.

            • by amorsen ( 7485 )

              Cooking is mostly electric already and unaffected by season. Transportation is mostly unaffected by season. Perhaps surprisingly, Denmark is already storing hot water for district heating from summer to winter. Once we have plentiful intermittent cheap electricity, that storage can be converted to multiweek instead of seasonal, which makes it 10 times as effective for almost the same cost.

              Norway and Sweden are transitioning to heat pumps from direct electric heating, which will free up a massive amount of w

              • Cooking is mostly electric already and unaffected by season. Transportation is mostly unaffected by season.

                My point was not that these things are seasonal, but that electricity is only a small part of our total energy requirements, and we need enough generating power or storage to handle the demand during the worst case scenario. Where I live, most suitable areas are already full of wind turbines, and they are only good for a rather insignificant part of our energy needs.

                • by amorsen ( 7485 )

                  Well luckily you mentioned Northern Europe where there is the entire North Sea available. Space for wind turbines is not a concern there.

    • by Kjella ( 173770 ) on Saturday December 07, 2019 @11:32AM (#59495112) Homepage

      Is this what passes for science these days? So much derp it's hard to know where to start. First, it doesn't "store gravitational energy" it stores kinetic energy.

      I think it's you that should hand in your nerd card. Kinetic energy is what you have when you're in motion, unless you're talking about a flywheel it's not something you store. What these blocks have is a higher gravitational potential. To maximize kinetic energy we'd throw them off a cliff, what we want is actually to extract as much work as possible with as little energy wasted on kinetics as possible. Think like a counterweight to an elevator, except we're not pulling the elevator up but a turbine around creating electricity. We operate tons of mines with dirt and gravel already, that is not groundbreaking at all.

      The question is if we can make this efficient enough that it's worth doing, truth is that simply moving mass around without releasing any chemical energy is very, very low energy density. Lowering one kilo one meter per second will only power one 9.81W light bulb, if we use LED that's a ~60W equivalent. For one hour, you need to move 3.6 tons one meter. Of course if the surplus energy would go to waste and you need the solar panels to survive mid-winter very low efficiency can be acceptable simply to get power when it's most needed.

    • First, it doesn't "store gravitational energy" it stores kinetic energy.
      Nope. Wrong.

      According to you, we would store energy if we move an object around on a parking lot.

      A flywheel stores kinetic energy ... perhaps you can understand your misconception.

    • huge water shortages, right? Especially in the Southwest United States? Also a huge part of the US Economy is California growing food with irrigation, so nobody gets away from those water shortages untouched.

      This is scientists doing what scientists do: basic research to solve long term problems.
    • "Is this what passes for science these days?"

      No. It's news and as always science news is poorly written. If you want science I'm looking forward to your peer reviewed, published takedown so we don't spend money on this.

      This may not be perfect, so let's work on refining it. Water would be good in high rain areas, but not everywhere.

    • Re: (Score:2, Insightful)

      Nuclear energy is the only proven non-CO2 emitting technology available to fill the gap.
      Yes, I agree wholeheartedly, but most humans are still superstitious cavemen who, when you even mention the word nuclear, immediately make warding signs against Evil, think zoomies BAD!, as their higher brain functions switch off and full-on caveman hardwired instinct mode switches on. The way some of these people talk makes me wonder if they have the urge to pick up the nearest club and try to beat a nuclear power pla
  • by LordHighExecutioner ( 4245243 ) on Saturday December 07, 2019 @09:49AM (#59494872)
    They will pay for a ticket to go by themselves up to the mountain top, and then being transported down through a toboga, producing energy.
  • by BAReFO0t ( 6240524 ) on Saturday December 07, 2019 @10:01AM (#59494890)

    I proposed having covered laked in mountain ranges to do this, at lease decade ago.

    But somehow it didn't come to me, to just use the rock itself, inside the mointain!

    That is honestly a really nice idea!

    As long as you don't make the mountain or shelf unstable, it should have no environmental impact at all! (Though I suppose you could also lift a whole mountain. Put it on enough stilts, one by one, and make sure it doesn't come apart at the faults.)

    Hell, we can start right now. Drill an elevator shaft, put a column of rock in as the elevator, connect the motor/generator, done!

  • Hmmm (Score:4, Informative)

    by rmdingler ( 1955220 ) on Saturday December 07, 2019 @10:03AM (#59494892) Journal

    They've done a little research, circumventing previous logical arguments against this technique: using sand/gravel instead of concrete blocks to minimize cost and CO2 offput, anchoring cables like a ski lift to minimize the interference of wind on crane cables, and reducing the precision with which loads must be picked up and set in place.

    Hydropower storage and generation is not ideal for every topography, and there is a considerable loss of stored energy with the inevitable evaporation of pumped water.

    This fails spectacularly as designed when compared to pumping water uphill, but it could be useful in some iteration where traditional energy storage systems are not feasible.

    • by Cy Guy ( 56083 ) *
      "anchoring cables like a ski lift"

      Climate change is responsible for closing a lot of smaller ski areas, so this would be a way to both provide jobs in those communities while actually fighting climate change by making solar power more viable as a 24/7 power source.

      Coal producing areas such as Appalachia also being impacted by transitioning away from a carbon economy could also benefit installing these systems.

      Both of those areas are already impacted by humans and thus lesson concerns of "Destroy[ing] nature
    • because they're a small country dependent on Hydro power (no, it wasn't because of the socialisms... sigh...). The US is likely to see similar droughts in the future and we'll be building desalinization plants just to have drinking water & food let alone hydro electric, so I could see this being useful.
  • I remember hearing about this back in college in the '80's. Nothing new. The idea was/is use solar/hydro to elevate"something" which stores potential energy.
    Also, many buildings in California have generators using large heavy wheels. Grid power runs motors that spin large heavy wheels which turn generators that generate power for the building. This smooths out frequent short term grid "blips" using the energy in the spinning wheel.

    Funny how everything old becomes "new" and "cool" when proposed by s
    • Bad ideas are the ones that keep coming back.

    • by ledow ( 319597 )

      We pretty much do this in every developed country already.

      Reservoirs and dams are used to push stored water through a turbine.

      When energy is in surplus, you pump water back up into the storage. It provides a consistent and predictable usage, soaks up surplus power, and you can just drain the thing for peak periods.

  • The new green way to power the world.

  • Click on the article to see picture of the idea. It looks like a gondola. Loading and unloading all of the sand/gravel into the "gondola cars" has to be wasteful. Why not just have one big car?

    I'm imagining a single huge car on a steeply inclined rail, like those industrial elevators you see in scifi movies, but much larger. I could see multiple cars that can be moved off the inclined rail for storage.

    • Why not just have one big car?
      Because you can run the system continuously.
      A single big car would need to stop or somehow be separated from the cable.

  • Why bring gravel up the mountain? Just grind up the mountain and throw it through the turbines on its way down.
  • Motors moving materials uphill just sounds incredibly inefficient. And this is very location based, dependent on the existence of these mountains. If we're going to focus on location based storage, how about vulcanos or geothermal, tapping existing gravitational and natural insulation created energies to leverage temperature differences.
    • Motors moving materials uphill just sounds incredibly inefficient.
      But they aren't. Why would they?
      First law of physics: conservation of energy ... you might not believe in it, but we have based our science on it.

      • There's going to be substantial losses in a system like this. Lots of moving parts in a mile long cable car system with heavy loads swinging from it.

        • 10% perhaps, just like with water ...
          There is no compelling reason why it should be more.

          • A company that builds cranes for shipping containers, claims 80% energy recovery on downward movements, and that's going straight down. Very unlikely that you can move a bunch of dirt diagonally off a mountain, plus have to deal with stacking/unstacking and get 90%.

  • by LynnwoodRooster ( 966895 ) on Saturday December 07, 2019 @11:47AM (#59495152) Journal

    I plan to call this venture SkyFall Lithium Crypto-AI Energy Solutions.

    Use solar/wind to crack water to create H2 and O2, so we can blast a rocket up into space with the generation payload.

    The payload consists of 20 tons of lithium batteries in a housing and a turbine on it, and some gyro stabilizers that are AI controlled.

    The rocket releases the payload just above the 62 mile height, and then the payload deploys it's 300 meter long rotor blades.

    As the payload descends to the earth, the turbine auto-rotates and charges the lithium batteries.

    Then we sell the batteries to EV consumers, and we use the crypto to guarantee the power inside came from a free-fall though the sky!

    Now, where's my $100MM VC investor who wants to make this a reality?

  • The key quote to look at in TFA is this:

    Given that batteries will provide a much cheaper and efficient alternative for short-term storage in the coming years, the MGES plant would be designed to store energy for long periods (seasonal and multiyear cycles), while batteries will fulfil the short-term energy storage needs.

    So this more expensive than batteries, which are more expensive than pumped storage (using a 40 year amortization period) - while having none of the advantage of batteries going where ever you want to put them.

    The longest term storage we need is on the order of weeks, which is the duration of the longest periods of insufficient wind and sun, so maintain power output with a moderate excess capacity. There is not use case where we need to store power for months, much le

  • Comment removed (Score:4, Informative)

    by account_deleted ( 4530225 ) on Saturday December 07, 2019 @09:39PM (#59496526)
    Comment removed based on user account deletion

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