Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Europe's deepest mine to become giant gravity battery

independent.co.uk

Post reply on HN
Print view View original

61–70 of 118 posts

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

#61

Post by riffraff »

undersuit wrote: post #53
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.

I believe that's how the US superfund was supposed to work (tax miners now so we can use that money to fix the damage they did if they won't) but this is no longer the case.

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

#62

Post by Log_out_ »

There was a plan, to use giant cylinders of landscape as hydraulic batteries.

The problem was the cost of excavation or building the cylinder. Then this came along, not even promoted as the future..

https://www.newcivilengineer.com/the-future-of/future-of-tun...

And it's ideal.as in they could turn testsites into batteries.

You could have such a battery in an any abandoned quary today. Chip the walls smoth, freeze an ice plug, pump water beneath and use the stored pressure.

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

#63

Post by kitd »

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…

Mine flooding was the driving force behind the development of the original steam engines.

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

#64

Post by lloeki »

GuB-42 wrote: post #25

Isn't there a better article? - 2 MW of energy MW is a unit of power not energy, maybe they mean 2 MWh, but if that's the case, it is a joke. That's like 30 Teslas cars, or half of a Tesla Megapack, which is a shipping container sized battery. 2 MW of power is not that big either, that's about what you get from a typical wind turbine. - 70TWh of energy At least, we have a proper unit, but I wish they tell us a bit mo…

> maybe they mean 2 MWh, but if that's the case, it is a joke. That's like 30 Teslas cars

Reminded me of the punchline to this water storage video:

https://m.youtube.com/watch?v=CMR9z9Xr8GM

That guy went mechanical with rocks:

https://m.youtube.com/watch?v=MVuVJC8lGck

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

#65

Post by onion2k »

undersuit wrote: post #53
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.

Wouldn't that require knowing how far down/across you're going to dig? Most mines have a known seam to begin with, but a lot of exploration and geology work comes later when there's a big hole to work from. There's only so much you can tell at the surface before you start.

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

#68

Post by Someone »

GuB-42 wrote: post #25

Isn't there a better article? - 2 MW of energy MW is a unit of power not energy, maybe they mean 2 MWh, but if that's the case, it is a joke. That's like 30 Teslas cars, or half of a Tesla Megapack, which is a shipping container sized battery. 2 MW of power is not that big either, that's about what you get from a typical wind turbine. - 70TWh of energy At least, we have a proper unit, but I wish they tell us a bit mo…

> At least, we have a proper unit, but I wish they tell us a bit more about how they got a number 7 orders of magnitude larger than the previous one.

The 70TWh isn’t for this mine, but globally. FTA:

“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.”

(See https://iiasa.ac.at/news/jan-2023/turning-abandoned-mines-in...)

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

#69

Post by 15457345234 »

danans wrote: post #59
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 lo…

Yeah, my surface level evaluation of these projects is that they're just not going to be viable - you have the height but you don't have the volume - mineshafts are by definition narrow - and some sort of automated load/unload system is going to run into issues of complexity and reliability and ease of access for maintenance to whatever's at the bottom end.

It's always going to be easier to move water around in an automated fashion, though, so I'm immediately skeptical of any system that isn't some variant of two tanks and a pump/turbine.

If you really do want to use gravity as a power source and don't want to go the hydro route you're better off building narrow-gauge train lines up the sides of hills. The lower-impact and lower-output version of that would be aerial ropeways.

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

#70

Post by 8bitsrule »

s1artibartfast wrote: post #56
alvah wrote: post #50

Earlier quoted context omitted.

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 capacit…

Here in the PNW,

"The Columbia River Gorge is a canyon ... up to 4,000 feet (1,200 m) deep [and which] stretches for over eighty miles (130 km) as the river winds westward [toward Portland]." - WPedia

Hmmm. Now I'm wondering how many reservoirs already (or could) exist above and along 80 miles of river. (No need to dig tunnels to the generators.)

Post reply on HN