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Europe's deepest mine to become giant gravity battery

independent.co.uk

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Re: Europe's deepest mine to become giant gravity battery

#51

Post by pfdietz »

hollerith wrote: post #46
pfdietz wrote: post #36

Earlier quoted context omitted.

You might be surprised at the enormous numbers of sites that are potentially suitable for pumped hydro, if you go looking for them in areas with vertical relief. https://re100.eng.anu.edu.au/global/ "ANU has identified 616,000 potential sites around the world." (note that not all countries are included in this because of lack of geographical elevation data) A place like Nevada has an enormous surfeit of opportunities…

Your second link describes itself as "a 1,000 megawatt energy storage project". I'm interested in how much energy the site can store , about which there is no indication on that page. Do you think maybe they mean 1,000 megawatt hour ?

It's to be a 8000 MWh storage facility that can charge/discharge at 1000 MW. So, eight hours of storage.

Re: Europe's deepest mine to become giant gravity battery

#52

Post by pfdietz »

stubish wrote: post #44
pfdietz wrote: post #36

Earlier quoted context omitted.

You might be surprised at the enormous numbers of sites that are potentially suitable for pumped hydro, if you go looking for them in areas with vertical relief. https://re100.eng.anu.edu.au/global/ "ANU has identified 616,000 potential sites around the world." (note that not all countries are included in this because of lack of geographical elevation data) A place like Nevada has an enormous surfeit of opportunities…

More holes than we have fresh water to fill them with. Maybe someone will solve corrosion and we can use salt water.

Fresh water consumption is small compared to that evaporated cooling a nuclear plant of the same average power throughput.

Re: Europe's deepest mine to become giant gravity battery

#53

Post by undersuit »

bunabhucan wrote: post #26

>The decommissioning of mine shafts is a costly and time-consuming process for mining companies. I wonder if that is part of the impetus - make cleanup/decommissioning happen in distant future dollars helps the balance sheet today. https://www.marketscreener.com/quote/stock/ABB-LTD-9365000/n...

I think that the cost(or even profits) of filling a mine back in after excavation should be considered from the beginning. Hell we could even sell the futures now to recoup the cost of building a mine tomorrow.

Re: Europe's deepest mine to become giant gravity battery

#55

Post by bnegreve »

stubish wrote: post #42
WalterBright wrote: post #22

Earlier quoted context omitted.

A gravity battery doesn't need a well or a tower. The slope of a hill will do. More or less put railroad tracks up the slope, and have the "car" winched up and down. Just like the ratcheting trolleys that go up and down hills.

There was recently an article here about an electric truck that never needs charging. It drives up a hill, collects a load of rock from the mine there, and by the time it has driven back down with the heavy load, regenerative breaking has recharged the battery.

Soon we will be hearing of the global flattening.

Re: Europe's deepest mine to become giant gravity battery

#56

Post by s1artibartfast »

alvah wrote: post #50
s1artibartfast wrote: post #35

Earlier quoted context omitted.

had to look up some price comparisons. Fengning Pumped Storage Power Station stores 40 GWh and cost 2 billion or 20 Wh/USD Tesla megapack 2 stores 3.8 Mwh = Costs 1.5 million, or approximately 2.6 Wh/USD It seems like pumped hydro is about an order of magnitude cheaper. https://en.wikipedia.org/wiki/Fengning_Pumped_Storage_Power_... https://en.wikipedia.org/wiki/Tesla_Megapack

That wasn’t the comparison. The comparison was every form of pumped storage EXCEPT pumped hydro vs a megapack. I’m sure you’re correct about pumped hydro though, it does seem like something we should do more of.

That was the comparison I felt compelled to make. I have been a big fan of pumped hydro for many years.

Contrary to what skeptics say, there are countless locations all over. [2]

There is a suitable location 3 times larger than the Chinese one I linked That could use California's sites reservoir [1] under construction as a lower basin. It would have a similar 400m head, and an upper reservoir with 3 times the capacity or 120 GWh.

https://en.wikipedia.org/wiki/Sites_Reservoir

https://re100.anu.edu.au/#share=g-e5955e35f1c7f3677ac265bcdd...

another: https://maps.nrel.gov/psh

Re: Europe's deepest mine to become giant gravity battery

#57

Post by beembeem »

fghorow wrote: post #4

It will be interesting to see how much net energy is able to be stored after the energy cost of de-watering the mine is taken into account. (An interesting tidbit of trivia I learned from miners is that deep underground mines only became feasible after reliable pumping was put in place.[1] Prior to that, they flooded out from groundwater intrusion.) [1] https://en.wikipedia.org/wiki/Flooded_mine Edited to add the wik…

One solution, you schedule pumping during times when the battery is charging, because presumably there is far more power available than can be used to charge the gravity battery anyways.

Re: Europe's deepest mine to become giant gravity battery

#58

Post by WalterBright »

stubish wrote: post #42
WalterBright wrote: post #22

Earlier quoted context omitted.

A gravity battery doesn't need a well or a tower. The slope of a hill will do. More or less put railroad tracks up the slope, and have the "car" winched up and down. Just like the ratcheting trolleys that go up and down hills.

There was recently an article here about an electric truck that never needs charging. It drives up a hill, collects a load of rock from the mine there, and by the time it has driven back down with the heavy load, regenerative breaking has recharged the battery.

While that makes perfect sense, I have read journalists claiming that Teslas were 110% efficient because of regenerative braking.

Re: Europe's deepest mine to become giant gravity battery

#59

Post by danans »

mhandley wrote: post #31

Dry sand has a mass of 1600kg/m^3 Potential energy, U = mgh. So the energy required to raise 1m^3 of sand 1400m is 1600 x 1400 x 9.8 = 22MJ = 6.1kWh I've no idea how large their mine galleries are, but lets say they're 3m wide x 2m high - in 500m of gallery, we can store 3000m^3 of sand, so that's 18MWh. I'm sure they've got a lot more space than that, but it just gives some idea of how much sand you're talking about…

> Potential energy, U = mgh. So the energy required to raise 1m^3 of sand 1400m is 1600 x 1400 x 9.8 = 22MJ = 6.1kWh

If you lowered 10 m^3 of sand (61kWh of potential energy), to generate the minimum 100kW power to participate in grid stabilization markets, you'd have to drop that 16000kg of sand for 61kWh/100kW = 0.61hr = 2196 sec. 1400 meters in 2196 seconds is 0.64 m/sec. That seems reasonable, but you'd need a lot of these (so a wide mineshaft) to generate a more meaningful amount of power (like at least 1 MW). Current grid scale batteries are capable of outputting hundreds of MW of power.

https://en.wikipedia.org/wiki/Battery_storage_power_station

> we can store 3000m^3 of sand, so that's 18MWh.

> I'm sure they've got a lot more space than that, but it just gives some idea of how much sand you're talking about.

They're going to need 3 orders of magnitude more space then because current generation grid scale batteries store GWh of energy, and generally speaking lower cost energy storage competes by offering much higher storage capacity.

Re: Europe's deepest mine to become giant gravity battery

#60

Post by fecal_henge »

alkonaut wrote: post #23
jcrawfordor wrote: post #19

Earlier quoted context omitted.

It's frustrating, every article just repeats "2MW capacity." Gravitricity hasn't announced this project themselves yet, hopefully when they do they give the actual storage capacity. But I think 2MWh might be correct - in press elsewhere Gravitricity says 500t over 800m produces 1MWh. This is a deeper depth but not that much, and this is very much an experimental project so I think they might be sticking to 500-750t m…

It’s a sad reality now, 1Mwh is sloppily called “1MW” when it’s about energy, but “1MW” when it’s about power. It’s just like the ship sailed on 1 kilocalorie.m being called “one calorie” I think we can give up on this one as well.

It all gets confusing when integrating power over a strange quantity of time. I wish we had some kind of rational unit to quantify energy
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