Coal mine shaft and winding tower [image credit: Andy Dingley @ Wikipedia]
Like pumped hydro or any gravity-based system it uses more power than it stores. Euan Mearns and Roger Andrews did an interesting analysis on this idea in 2018, comparing it to batteries and hydro. One issue is finding enough suitable disused mine shafts that aren’t flooded. At least heavy weights don’t degrade over time, unlike batteries.
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The pilot project aims to demonstrate the firm’s technology, which works by using excess electricity to lift 12,000 tonnes of weights in a deep shaft and releasing them at a later time to generate energy, says Energy Live News.
The trial aims to assess the response speed of energy generation once the weights are released.
The start-up has signed a land rental agreement with port operator Forth Ports for the demonstration project.
Construction work for the £1 million project is scheduled to commence in October 2020, with December marked for the commercial launch.
Gravitricity Lead Engineer Miles Franklin, said: “This grid-connected demonstrator will use two 25-tonne weights suspended by steel cables. In our first test, we’ll drop the weights together to generate full power and verify our speed of response. We calculate we can go from zero to full power in less than a second – which can be extremely valuable in the frequency response and back-up power markets.
Full article here.
Tallbloke's Talkshop 
Another sacrificial investment on the altar of emissions.
“we can go from zero to full power in less than a second.”
And stay at full power for another 15 seconds (my guess)
Sounds like they’re digging a new shaft, it mentions leasing land from the Port of Leith.
Just think of the seismic shock if 12,000 tons were to fall out of control. It would make fracking tremors pale into insignificance. And while the weights might not degrade, the cables will…
‘Each unit can be configured to produce between 1 and 20MW peak power, with output duration from 15 minutes to 8 hours.
. . .
Bloomberg New Energy Finance [Global Energy Outlook 2018] has forecast over $620 billion of global spend on energy storage to 2040. Today, new energy storage technology investment is around $5 billion per year, this will grow to £50 billion by 2040.’
https://www.gravitricity.com
That’s a lot of mine shafts 🤔
£1m gravity energy storage pilot system to be built in UK
11 MAY 2020
Gravitricity, the team behind a system that stores excess renewable energy in weights suspended above disused mine shafts, is set to build a £1 million demonstration of the technology after securing a land rental agreement in Edinburgh, UK. According to news website Business Green, Gravitricity plans to start building work on the project in October 2020 on an industrial site near the Port of Leith in Edinburgh.
http://www.hazardexonthenet.net/article/178416/-1m-gravity-energy-storage-pilot-system-to-be-built-in-UK.aspx
They claim: ‘Cost effective – levelised costs well below lithium batteries’.
It’s a wonder they haven’t come out with the idea of as one weight goes down, the other rises – like the Falkirk wheel idea – hey man you could have perpetual motion – the greens would like that: – just another equally useless idea like vehicles driving along the road and generating power for the streetlights.
The idea requires mine shafts, so they depend on what fossil fuel did. And if more storage is needed then more mines will have to be dug.
How about making smaller wind turbines out of metal that can be recycled?
Then using high pressure steam to turn them, steady and reliable.
You could burn clean, cheap natural gas to generate the steam….
Well, if you just use thermal generation to spin up heavy steam turbines, you don’t need “frequency response” because you have spinning synchronous inertia.
This is just another expensive band-aid to patch over the gangrenous wound of unreliable intermittent power. It can’t be better than pumped hydraulic storage, therefore it can’t work. Even pumped hydro cannot get the ERoEI ratio for wind above 7:1. We need over 30:1 to replace coal and keep our civilization from collapsing.
All these Eco Schemers should be told to put a sock in it until their crazed proposals can better the ERoEI ratio of Thorium power.
How much money are the owners of Gravitricity putting into this project to show their faith in it? I assume nothing like all the green pie in the sky scams.
For this to be useful they would need to buy the power used to raise the weights at a very low or even minus cost and then have a fast reaction standby generator that starts the moment the weights start falling and hope it is up to power by the time the weights reach the bottom. Would be much easier to build a large HELE coal fired plant to run 24/7.
It might have some small merit if some of the money spent on constraint payments to wind turbine operators was saved by having them generate power to raise weights.
Aye, er em, Energy expended in raising weights ….. isn’t that what “They” do in the Gym? Seemsso foolish that ALL Gym machinery isn’t connected to produce the great energy form – Alec Tricity invented and called after himself many years ago – good old Alex.
Considerall the Water that is drunk from plaastic bottles in the Gymns and the water & Soap to wash the sweat etc and the Aircon in the room.. What you telling me the Gyms are heated ?
konradwp1 says:
“Thorium power”
I was with you pretty much until then. Please, please give me a link to a working reactor, otherwise it is powerpoint and worth just as much as Gravitricity’s idea.
To get any decent energy out of this system surely requires multiple weights and some way of parking them at the bottom by trundling them off into tunnels. If so, doesn’t it make more sense to pump water out of the flooded mine and just let it flow back through a turbine? If there’s even a big space still remaining underground – I thought played out mines were generally collapsed.
and the energy density will be measured in hundreds of hectares per megawatt-hour with a median run time of 15 minutes.
And the cost per MWH over the lifespan of this Rube Goldberg devices will be how many millions?
I’d rather trust She Guevara on this.
More money down a black hole.
Maybe more suitable to build it into new tower block, like an extra lift shaft. Add it to solar panels on exterior walls and turbines on the roof and you’ve got the ideal HQ for all the green luvvies.
Hah
Wouldn’t have a mine shaft to play with if it wasn’t for coal mining fossil fuel’ers !
@Stuart
Just because someone mentions “Thorium”, doesn’t necessarily mean “LFTR”.
LFTR shows promise, however only two experimental units were ever built, and the experiments ended in 1969. It would take a lot of work to make up for the lost years and get a modern unit designed for producing civilian power.
But LFTR is not the only way of exploiting the abundance of Thorium. The heavy water CANDU reactor is a proven technology. The new design is the AFCR (Advanced Fuel CANDU Reactor). This can make use of Thorium and even spent fuel from older reactors.
AFCR is what can be built now.
konradwp1 chided:
“Thorium”, doesn’t necessarily mean “LFTR”
My apologies, Konrad, quite right. And thank you for sending me off on a fun search for details on the AFCR. Since it can re-use spent fuel from PWRs the Chinese are very interested but haven’t built any yet.
Dragging the comment back on topic, I remembered this from the sadly defunct ‘Energy Matters’ blog:
http://euanmearns.com/short-term-energy-storage-with-gravitricity-iron-versus-ion/
and
http://euanmearns.com/is-ares-the-solution-to-the-energy-storage-problem/
It occurs to me that there are a lot of mountains and empty space in Scotland to soak up all that wind energy 🙂