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Power

Deep Abandoned Mine In Finland To Be Turned Into a Giant Gravity Battery (iflscience.com) 131

James Felton reports via IFL Science: One of the deepest metal mines in Europe -- the Pyhasalmi Mine in central Finland -- is to be turned into an enormous gravity battery capable of storing 2 megawatts of energy. [...] Despite the cool name, the idea behind gravity batteries is really simple. During times when energy sources are producing more energy than the demand, the excess energy is used to move weights (in the form of water or sometimes sand) upwards, turning it into potential energy. When the power supply is low, these objects can then be released, powering turbines as our good friend (and deadly enemy) gravity sends them towards the Earth.

Though generally gravity batteries take the form of reservoirs, abandoned mines moving sand or other weights up when excess power is being produced have also been suggested. Scottish company Gravitricity created a system of winches and hoists that can be installed in such disused mineshafts. The company will install the system in the 1,400-meter-deep (4,600 feet) zinc and copper mine in Pyhajarvi, Finland.
"A study last year by the International Institute for Applied Systems Analysis (IIASA) estimated that gravity batteries in abandoned underground mines could store up to 70TWh of energy -- enough to meet global electricity demands," reports The Independent. "The repurposed mines could also provide economic benefits to the communities that previously relied on the mine for their livelihoods."
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Deep Abandoned Mine In Finland To Be Turned Into a Giant Gravity Battery

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  • Two megawhats? (Score:5, Insightful)

    by blugalf ( 7063499 ) on Thursday February 08, 2024 @05:03AM (#64224150)
    Megawatthours, years, minutes, milliseconds?
    • by AmiMoJo ( 196126 )

      I can't find the actual answer, it doesn't even say on their corporate website. I would guess 2 MWh, it's only a demonstrator.

      • by Anonymous Coward

        Then again, could be only 2MJoules (or .00000055 MWh) !

      • I don't know where the number was pulled from, but the original plan was to have 75MW power production capacity, and storage capacity of 530 MWh. Which is not too bad considering that Finland has about 14 GW peak energy consumption, and hydroelectric capacity peaks at about 1.2 GW. It is also not a game changer alone, but it would help to collect wind energy during the night times and also even out the morning and 5-to-7 PM peaks in power usage.

        The plant has been planned for a couple of years now, and it wa

    • Re:Two megawhats? (Score:5, Informative)

      by Tx ( 96709 ) on Thursday February 08, 2024 @05:31AM (#64224184) Journal

      Sad that none of the tech journalists that copy-pasted this story on all the sites I just looked through, asked the same question. However from a blog post on Gravitricity's web site, it mentions "...you have to drop 500 tonnes around 800 metres to generate 1MWh". Here we have a 1400m shaft, so dropping a 500 tonne weight down that would be 1.75mWh. A weight of a little over 500 tonnes doesn't seem infeasible, so 2MWh is probably right.

      • Re:Two megawhats? (Score:5, Insightful)

        by thegarbz ( 1787294 ) on Thursday February 08, 2024 @06:56AM (#64224296)

        Tech journalists are nothing more than journalists writing about tech. They largely are clueless as to what they are actually writing about. What is really sad is I've seen engineers make this mistake.

        Though I'll ask the question, just how many Casio watches and how long can you power them with only 1.75mWh ;-)

        • by q_e_t ( 5104099 )
          There are a few out there who were scientists but didn't enjoy the grant application treadmill.
        • by irving47 ( 73147 )

          MWh or mWh?

      • There are probably some conversion inefficiencies. How much usable energy comes out of this?
        • Usually if one says he has stored X MWh, then that means he can produce that X MWh.
          What do you care how much loss he has?

          If you attack a solar plant to my grid, I want to know what is the peak power and at what time of the day. I do not care if your panels are 18% effective or 24% effective.

          • What do you care how much loss he has?

            Because the energy you put in has costs and these have to be covered somehow.

          • Usually, usually isn't a word I would associate with startups. I don't think there is an accepted industry definition here, and even if there were, I am willing to bet that the startup is willing to bend the rules a bit. While efficiency is likely to be a factor somewhere between 0.5 and 1, that can be the difference for something that is profitable to operate.
      • Sad that none of the tech journalists that copy-pasted this story on all the sites I just looked through, asked the same question. However from a blog post on Gravitricity's web site, it mentions "...you have to drop 500 tonnes around 800 metres to generate 1MWh". Here we have a 1400m shaft, so dropping a 500 tonne weight down that would be 1.75mWh. A weight of a little over 500 tonnes doesn't seem infeasible, so 2MWh is probably right.

        The article says the mine is 1444 meters deep but the shaft they are using for a "full scale test" is 530 meters. There may not be a single shaft that descends to the full 1444 meters depth

        • Also the shaft has to be big enough for the weight they would use in the full scale test. It might be that the single shaft narrows as it goes down.
    • by quenda ( 644621 )

      I auto-corrected it to two mega-joules. Was not impressed.

    • by q_e_t ( 5104099 )
      Indeed, TFS fails physics class due to unit illiteracy.
    • These types of articles lose all their credibility when they can't even express their key datapoint in an appropriate unit measure, i.e. MW is a measure of power, not energy.

  • by johnw ( 3725 ) on Thursday February 08, 2024 @05:24AM (#64224174)

    Two megawatts of energy Doesn't anyone proofread this kind of thing?

  • by nothinginparticular ( 6181282 ) on Thursday February 08, 2024 @05:33AM (#64224186)
    In both senses of the word
  • Wouldn't such systems store so little energy that it would be far more cost efficient to just buy more energy than to build?

    I mean, it's a cool little project, but there are opportunity costs too...

    • Our office is in a very tall building and there is a version of this in all the elevators, the legend is it does save power.

  • by mr.gson ( 458099 ) on Thursday February 08, 2024 @06:22AM (#64224240)

    The news here in Finland was that the project was already abandoned back in November: https://www.epv.fi/en/project/... [www.epv.fi]

  • In the UK (Score:4, Interesting)

    by dlarge6510 ( 10394451 ) on Thursday February 08, 2024 @06:27AM (#64224252)

    We have been thinking of using old mines as geo-thermal powerstations as they typically fill with water and naturally get quite warm so that heat can be reused if we transfer it with a simple pipe and pumed water.

    Also, the article says 70TWh of energy meets global demand?

    I think that is way underestimated:

    https://www.statista.com/stati... [statista.com]

    • We have been thinking of using old mines as geo-thermal powerstations as they typically fill with water and naturally get quite warm so that heat can be reused if we transfer it with a simple pipe and pumed water.

      That's actually quite a bad idea. Mines by their nature do not generate a considerable amount of energy in the form of heat. The proposal is far more expensive and energy intensive than simply drilling deep wells which could be injected also provide thermal power. Additionally you need a *LOT* of heat to make any meaningful conversion to electricity so none of these existing mines or proposed wells are actually suitable for geothermal power stations. New wells are however being looked at to provide district

      • Woopse forgot a second set of quote tags.

      • That's actually quite a bad idea. Mines by their nature do not generate a considerable amount of energy in the form of heat.

        Well, I'll defer to your superior understanding form wherever you are, but as a geologist within an hour's drive of several of the proposed schemes, I think it's a reasonably good idea.

        I've also got a pretty good idea (from having done it well over 100 times) of the effort (and working space, and paperwork) involved in drilling a "mere" 2.5km deep well. I wouldn't wish the NIMBYs on a

      • > Additionally you need a *LOT* of heat to make any meaningful conversion to electricity

        Did I say it was being convereted to electricity?

        I think it's more for domestic heating, heat pumps basically.

    • by Samare ( 2779329 )

      The original article doesn't actually say that it meets global demand: https://www.mdpi.com/1996-1073... [mdpi.com]

      Just that "UGES is a particularly interesting technology for long-term energy storage to reduce seasonal fluctuations in electricity demand and wind and solar generation.".

    • The statisa link indicates that net electricity consumption worldwide was 25,530 TWh for 2022
      It just so happens that 25,530TWh/70TWh=364.71
      Which is too close to the number of days in a year to be a coincidence.
      So given that this is about energy storage I think they mean that 70TWh is enough to store/supply 1 day's worth of global electricity demand.

      The article actually states that "The technology is estimated to have a global potential of 7 to 70 TWh".
      So it seems that The Independent writer(Anthony Cuthbert

  • by gweihir ( 88907 ) on Thursday February 08, 2024 @06:38AM (#64224274)

    "Megawatt" is not a unit of energy.

  • by Ecuador ( 740021 ) on Thursday February 08, 2024 @06:58AM (#64224300) Homepage

    This is very confusing, the company themselves delivering the technology tweeted (https://twitter.com/CallioPyhajarvi/status/1754375348131676283):

    > Plans unveiled to convert Europe's deepest zinc and copper mine into 2MW gravity energy plant.

    This makes little sense, so it's not a battery, it's an energy plant? Making 2MW of continuous power out of... what? They link to an article for more information (https://www.heraldscotland.com/news/24094926.gravitricity-demonstrate-energy-storage-tech-deep-mine/):

    > It added that the scheme being developed would deliver up to two megawatts of storage capacity, declaring: “This would tie straight into the local electricity grid and provide balancing services to the Finnish network.”

    So it IS a battery after all? With... "two megawatts of storage capacity" - which is nonsensical of course. Maybe it's connection can deliver up to 2MW of power when needed, but, still, WHAT'S THE ACTUAL CAPACITY?

    Maybe they have no idea themselves? Doesn't seem like a serious outfit...

    • When fully charged it is supposed to deliver 2MWh before it is empty. It then takes 2MWh*loss factor to recharge.

      2MWh is not very much but about all you can do in a mine shaft despite its depth, gravity is a weak force.

    • I wonder about swirling around toxic runoff, and how much of the water would leak out -- and how much energy lost to the pumps.

  • by cmseagle ( 1195671 ) on Thursday February 08, 2024 @07:05AM (#64224308)

    2MWh of Li-ion battery capacity will set you back about $300k. Even if they massively scale up production I don't see them being able to acquire an abandoned mine and install an apparatus capable of dropping hundreds of tons of counterweight down a shaft for that kind of money.

    Nifty idea, but I expect the economics will kill them (if they haven't already, based on comments from other posters).

    • Plus there are reliability concerns. Even if they only run this at times of peak grid demand and sell the power for say 50c/kWh then it's only generating EUR1000 each time they run it and sell all the power (hopefully they can charge at practically zero). The staff and maintenance to keep such a large machine operating seem like they'll readily eat into all of that.
      • Completely agree. Scalability is a massive concern as well. It's much, much easier to plop another 2MWh of battery into the middle of some empty field that is presumably already allocated to the purpose than it is to find another mine shaft and install some bespoke piece of kit.

        And then can you even maintain the things? Imagine sending engineers all over the hinterlands to your collection of mineshafts, as opposed to having a team permanently stationed at said empty field containing batteries offering th

        • I wonder if we could retrofit water towers? They already have pumps that fill the tower and presumably most of the time the tower doesn't need to be completely full. I imagine they are already smart enough to only pump water when the level is really low or the power is really cheap, but you could have them run that water back downhill again at peak hours and run the power back into the grid.
  • by JamesTRexx ( 675890 ) on Thursday February 08, 2024 @07:57AM (#64224392) Journal

    to see the reserves from any storage project dwindle fast because of cryptocurrency and AI use.

  • Sounds Familiar (Score:5, Informative)

    by quantaman ( 517394 ) on Thursday February 08, 2024 @07:57AM (#64224394)

    Back in 2016 I heard about the same thing being done with trains [vox.com].

    The company's website is still around but their news section hasn't been updated since 2020 [aresnorthamerica.com], I'm guessing dropping battery prices killed their economics. And given the efficiency of trains it's hard to see the mine shaft as being much more efficient.

    And on the topic of gravity storage how is it that none of these companies are using the most obvious startup name possible [wikipedia.org].

  • One can fill 100 ton railroad cars with sand/rock, move them up hill in summers and store them up in the plateau. Then roll them down in winter... Did some back of the envelope calc. It's not likely to beat batteries in cost. But energy storage for months possible
  • Reality check (Score:5, Interesting)

    by Luckyo ( 1726890 ) on Thursday February 08, 2024 @08:13AM (#64224422)

    Gravity batteries using solids and pulleys and cranes seem to have become the new perpetual motion engines. We know from underlying physics that they would be utterly awful (material costs, friction losses, durability), but there's money on the table, so there are people to take it.

    Gravity batteries that could be made to work are made with liquids, not solids. Same reason why when you ship huge amounts of freight, you don't do it via truck or rail, you do it via barge or ship. Friction losses compound rapidly, as do durability issues (many of which are friction related) as mass of the object being moved around increases. Flowing through a lubricant is energetically cheap. Wheeling solid things on top of one another is much more energetically expensive.

    So since people selling these modern day perpetual motion engines know they're selling you something that won't work at any meaningful scale, their promotional materials aren't written as technical descriptions used to promote them to civil engineers so the tech becomes popular. They're written for layman activists to promote them to other laymen.

    In case you doubt this, here's this company's promotional video from recent past. Yes, like all modern scammers in this field, they were crowdfunding much of their modern day perpetual motion engines until they get big enough for government level subsidies.

    https://www.youtube.com/watch?... [youtube.com]

    And for those wondering why the mine isn't being used to liquid gravity battery. That was the original plan. Problem is that groundwater penetrated into the mine and started flooding parts of it, making these plans unfeasible.

    This is an article about the plans from our local former engineering magazine that used to be sent to all members of Engineer Union until a few years ago after quality crashed as it was less and less engineers writing for engineers and more and more humanist babble with not a shred of understanding of engineering pretending to be an engineering magazine.

    https://www.tekniikkatalous.fi... [tekniikkatalous.fi]

    It notably also doesn't tell us how much energy they actually plan to be able to store citing the same "energy equals mass times speed^2, not mass times speed^2 per time^2, because I'm totally an engineer writing for formerly engineering magazine that is now another humanist rag written by people who barely scraped by through lyceum's physics course". Reading it reminded me once again why it's not longer one of the perks of membership of Engineering Union to get this formerly excellent piece of news media.

    • Re: Reality check (Score:3, Insightful)

      by nategasser ( 224001 )

      I think there's interest in gravity (and other large) battery systems despite pretty high inefficiencies, because they pair well with wind and solar generation which need stored energy when they're not generating, and which don't dial down when demand falls, like a gas plant. So you're throwing energy away during the day and importing it at high cost at night. Even a relatively inefficient battery can help with that situation.

    • by Anonymous Coward

      Gravity batteries that could be made to work are made with liquids, not solids.

      Like pumped storage hydropower (PSH)?

    • Just out of curiosity, would it make more sense to recondition old oil platforms for a gravity battery? Then you wouldn't really need to spend so much energy lifting the load, you could just inflate some sacks and float it it back up, then let it drop back down to create the energy.

      • by saider ( 177166 )

        The inflation would have to overcome the pressure, which is the weight of the water column on top of the payload. The deeper you go, the more water you need to "lift" to inflate the sacks.

        I'm not sure if that math would add up, but it certainly is an interesting idea.

      • The water would seriously reduce your gains.
        1. You'd need to subtract the mass of the displaced water from the weight of your dropping mass, which would mean you need a much, much, heavier load to get useful power.
        2. If you drop at any real rate of speed, you'd need to account for power loss from the drag of the water - much like air resistance is the main energy cost for cars at any real speeds. And water drag is a real pain. It's why ships have been "streamlined" for ages. This would be straight up l

  • ...stores 1.3 mw of power... ...maybe i can sell that to finland?...
  • by Ol Olsoc ( 1175323 ) on Thursday February 08, 2024 @09:20AM (#64224588)
    This is just a rebranded energy vault. Thunderfoot has something to say on that https://www.youtube.com/watch?... [youtube.com] https://www.youtube.com/watch?... [youtube.com] .

    If Thunderfoot is too acerbic for you, here's another one https://www.youtube.com/watch?... [youtube.com]

    • The last link is a duplicate of second one.

      • The last link is a duplicate of second one.

        Sorry about that - a copypasta error.

        • Buy artesian original pasta, not knock-off pirated pasta. (Yes, I know [wikipedia.org].)
          • Buy artesian original pasta, not knock-off pirated pasta. (Yes, I know [wikipedia.org].)

            Does anyone else here remember spinach pasta in the form of little wagon wheels?

            • Specifically spinach pasta, I'm not sure about. But you can get "tricolore" pasta here in yellow (natural), green and reddish-orange (I'd have to take my colour reference chart book to the supermarket to be more accurate) at the local Lidl - and possibly other stores too. But Lidl has a reputation for slightly off-normal continental (i.e. Europe mainland) products, and this is sufficiently oddball to fit in. I haven't noticed it anywhere else, but I can't say I look too closely at pasta - it's a filler mate
              • Specifically spinach pasta, I'm not sure about. But you can get "tricolore" pasta here in yellow (natural), green and reddish-orange (I'd have to take my colour reference chart book to the supermarket to be more accurate) at the local Lidl - and possibly other stores too. But Lidl has a reputation for slightly off-normal continental (i.e. Europe mainland) products, and this is sufficiently oddball to fit in. I haven't noticed it anywhere else, but I can't say I look too closely at pasta - it's a filler material.

                I assumed the "reddish" pasta was just a dye, but it might be ... paprika, perhaps? I'm sufficiently interested now to RTFpackage.

                Oh, shape : circular extrusions with about 6 radial ribs from the centre ; about 2cm diameter by half a cm extrusion length.

                Is that the stuff you're thinking of?

                Here in the States, we have spinach, sun dried tomato, and of course standard semolina pasta, respectively green, reddish, and blond. Oh, and whole wheat (abomination!) and gluten free. Seriously, it's sad that whole wheat pasta exists, the texture is terrible.

                The little wheels are about as you describe - maybe 5 spokes instead of six.. The Italian part of my heritage also has a lot of different shapes in use, which depends on what sauce is going with the pasta. Only us Italians can make a whole galaxy o

                • If I cared enough, I'd check my suspicion that pasta was invented in "China" (+/-) and imported to Italy by that Marco Columbus guy. But I'm one of those "it all comes out the same" people when it comes to cooking - very much a user level user. Forever having to separate the incinerated bits from the bits with some residual nutritional value, because I tend to do something interesting while I'm cooking, and forget about whatever is cooking.

                  I can't say I've *ever* looked at the flour type for a pasta. Why i

                  • If I cared enough, I'd check my suspicion that pasta was invented in "China" (+/-) and imported to Italy by that Marco Columbus guy. But I'm one of those "it all comes out the same" people when it comes to cooking - very much a user level user. Forever having to separate the incinerated bits from the bits with some residual nutritional value, because I tend to do something interesting while I'm cooking, and forget about whatever is cooking.

                    I can't say I've *ever* looked at the flour type for a pasta. Why is whole wheat such an abomination? Is that a universal opinion (in cookery? Impossible!), or a personal preference.

                    Isn't "durum" a breed of wheat?

                    Whole wheat noodles have a weird texture, at least to me. Taste is okay, but part of the fun of eating pasta is the texture. I even got a few "knock it off's" when I'd play with my spiral noodles as a kid. Whole wheat noodles just feel bumpy and creepy, like regular noodles with a bad case of acne.

                    The wheat type is durum wheat. The flour depends on what part of the grain it is made from. Durum flour comes from the endosperm of the grain, and semolina flour from the whole grain. Durum flour is great in br

                    • Whole wheat noodles just feel bumpy and creepy, like regular noodles with a bad case of acne.

                      Reminds me of when I discovered "tofu" in the health-foods store (the only one in a city of a quarter million people) after I turned vegan. Weird texture (because it was dried, then rehydrated as I cooked it), but I could read the composition data and knew I needed to cover the protein requirements of my diet, and I came to like it. I've never taken to "fresh" tofu since that became available.

                    • Whole wheat noodles just feel bumpy and creepy, like regular noodles with a bad case of acne.

                      Reminds me of when I discovered "tofu" in the health-foods store (the only one in a city of a quarter million people) after I turned vegan. Weird texture (because it was dried, then rehydrated as I cooked it), but I could read the composition data and knew I needed to cover the protein requirements of my diet, and I came to like it. I've never taken to "fresh" tofu since that became available.

                      Ah - have you ever had the so-called "stinky tofu"? It's fermented, although there might be something else going on for it to smell so bad they gave it that name.

                    • Never heard of it. But since I like my rotten milk (the smelly end of the "cheese spectrum"), I'll remember it if I see it anywhere.
  • Projects like this only bring in positive economics during construction, after that the maintenance is minimal and the expertise is usually brought in for short term projects. There's no local economic impact on an ongoing basis.

    Profit sharing is possible, but doesn't usually benefit individuals in the area.

    • by Anonymous Coward

      Projects like this only bring in positive economics during construction, after that the maintenance is minimal and the expertise is usually brought in for short term projects. There's no local economic impact on an ongoing basis.

      Yes that's true of a lot of project and it sounds like you're framing it as a bad thing.
      This kind of thinking is pervasive in so many renewable energy projects to convince the public that it's good, i.e. they create jobs on an ongoing basis. This is a more polite way of saying it needs more maintenance and has high ongoing costs.
      If you had a handful of competing forms of renewable energy, would you prefer to pay for the more expensive less reliable one just because it employs more people? Do you make the s

  • I have just built a a capacitor capable of storing 2 Megawatts/Picoseconds. Where's my $MONEYs?!
  • Battery is more than one of something. So it's a gravity cell or a gravity capacitor, isn't it?

    The semantics portion of my brain is in re-"volt". Sorry. Had to.

  • I ran the calcs to put one in my backyard to see if it could backup my house, you'd need a very large or very high gravity battery. I think compressed air storage is better, but more lossy.
  • The ability to store only 2MWh (assuming posters are correct the summary left off it was for an hour) for one of the deepest mines in Finland tells me it is not a good idea. A typical turbine of today is 2MW generation. So the mine would only cover an hour if the wind is still for ONE turbine.
  • Did I get the maths right? In order to get 70TWh with a 1400 meter deep wheel, you need to move 178 kilotons down the wheel.
    • by catprog ( 849688 )

      178 * 1000 metric tons / 1 metric ton * 14 * .272kwh in GWh = 0.67GWh

      (I think 1 ton droped 100m is equivelent to .272kwh)

  • Three of them, in fact.

  • When we do it with water, it's called "pumped storage hydropower" https://en.wikipedia.org/wiki/... [wikipedia.org] and it's been around for a LONG time. I can't imagine that doing it with sand or rocks would be more efficient or less expensive.

IF I HAD A MINE SHAFT, I don't think I would just abandon it. There's got to be a better way. -- Jack Handley, The New Mexican, 1988.

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