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These scientific advances in batteries are cool, but I don't take them as a specific indicator of what is coming. It is a numbers game, if there are 1000 scient

These scientific advances in batteries are cool, but I don't take them as a specific indicator of what is coming. It is a numbers game, if there are 1000 scientific advances maybe 1 or 2 will survive the gauntlet and make it into manufacturing in the next 10 years. It seems reasonable that there will be battery options that cost 50% as much and others that have 2x greater energy density in the near future. That seems great to me. Batteries will be viable and economical across most storage needs expect for aviation, shipping and seasonal grid storage.

SV_BubbleTime 4y ago
Same. If you follow articles like this you’ll be constantly wondering what happened to “x”. (“Graphene can do everything except get out of the lab”)
RGamma 4y ago
Specifically for grid storage I'd like to see more attention given to gravity batteries [0], the compressed liquid type. Recently saw a video (in German, [1]) in which there was back-of-the-envelope calculation that a gravity battery built by hydraulically raising a cylindrical landmass with 1km diameter by 500 meters stores about 2TWh (recent yearly gross electricity consumption of Germany is 560TWh). It's such a simple concept! Also, they are looking for investors: https://heindl-energy.com/ https://heindl-energy.com/ [0] https://en.wikipedia.org/wiki/Gravity_battery https://en.wikipedia.org/wiki/Gravity_battery [1] https://youtube.com/watch?v=pnomwGCBNAE https://youtube.com/watch?v=pnomwGCBNAE
- AndrewDucker 4y ago
  That is an obscenely large cylinder. And a large height to raise it!
- amalcon 4y ago
  Pumped-storage hydro (the cheapest and generally most practical gravity battery) is currently responsible for almost all grid-scale energy storage worldwide. I don't think it's fair to say it's not getting attention. What's not getting attention is the use of solids for this. The main reasons are that you'd like to re-use most of the infrastructure of the hydroelectric dam you wanted anyway, and that liquids make for simpler engineering in these cases.
  - toss1 4y ago
    What is interesting about a quick look at the Heindl Energy solution is that it looks like basically pumped hydro. The difference is that the water is sitting in a large cylindrical space underground with a large (minimum 100m / 300ft diameter) rock piston sitting on top of the water. Eliminates the need for mountainous terrain with a high lake-like geometry to pump the water up out of the gravity well — they can build this in the flatlands
  - narrator 4y ago
    I just had a wonderful and possibly stupid idea. How about pumped hydro with a huge storage tank on the surface and then another huge one at the bottom of a cavern made by an underground nuke test? The main problem of course is that the underground cavern is in the middle of nowhere and radioactive. Maybe you could remediate the pollution in the cavern by filtering the actinides while pumping the water around?
- acc_297 4y ago
  There are simpler technologies that already exist on this principle pumped hydro being the main one this proposal seems like overkill to have so much storage in a single location
  - RGamma 4y ago
    Well of course you can divide up the mass and build several smaller installations. I was merely hinting at the fact that pumped hydro storage can be made more compact and flexible by compressing the liquid with a piston.
- mgsouth 4y ago
  I'm assuming it's a cylinder 500 m tall, lifted by 500 m so it almost clears the hole (assuming basalt at 2.9 g/cm^3, that's only 1.6 TWh, but close enough.) Watching a 1 km-wide 150-story structure rise from a hole and then disappear would certainly be a majestic sight. However, a few issues: - The Mir mine, 4th deepest open-pit mine in the world, has roughly these dimensions (1,200 m wide x 525 m deep) [1]. Of course, its approximately a cone, so its total volume would be about half the proposed cylinder. The mine took 40 years to excavate, albiet in very harsh conditions. - Simply removing the rock from the hole, with 100% efficiency, would expend 1 TWh of energy (average lift 1/2 of total height). If diesel powered construction equipment is used, theoretical maximum efficiency of just the engines is 50%, realistic is more like 20%. I'd be surprised if you could get a total efficiency of over 1 or 2%. - Of course, you'd also spend energy moving the overburden away from the hole. If the angle of repose was 1-in-5, then the pile would be roughly 150 m (45 stories) at the tallest point, and form a circle 4 km wide centered around the hole. - You could be clever, and just dig out the circumference and bottom of the cylinder. At the bottom every square meter would have 500 meters of rock sitting on top of it. That's 1.5 million kg, or 14,000 kPa (2,000 PSI). That doesn't sound... impossible... but it would require a dense forest of supports. It would be the world's most expensive room-and-pillar mine [2], by several orders of magnitude. Integrity of the rock would be a problem, too. A fault wouldn't just risk a tunnel wall blow-out or cave in, it could litteraly drop a 500 meter mountain on your head. - Speaking of pressure... how do you perfectly maintain the integrity of a 3 km circumference piston ring? The water is going to really, really want to slip past the rock piston. Anywhere it does it will have very serious erosion. How do you fix a problem? Picture one of those submarine movies with water spraying everywhere, but unable to shut it off. - Speaking of pressure, again... how do you maintain the integrity of the rock? You'd have to girdle it in a 3 km x 500 m tall wall. - You still need a very large water reservoir. [1] https://en.wikipedia.org/wiki/Mir_mine https://en.wikipedia.org/wiki/Mir_mine [2] https://en.wikipedia.org/wiki/Room_and_pillar_mining https://en.wikipedia.org/wiki/Room_and_pillar_mining
  - RGamma 4y ago
    Good clarification. Perhaps it would be better then to build these at smaller scales (as they suggest on their website) ;) In the video this example is chosen to compare it with the area requirements of conventional pumped hydro as well as to show what magnitude of energy storage would be necessary to compensate for fluctuating solar/wind production.

SV_BubbleTime 4y ago

Same. If you follow articles like this you’ll be constantly wondering what happened to “x”. (“Graphene can do everything except get out of the lab”)

RGamma 4y ago

Specifically for grid storage I'd like to see more attention given to gravity batteries [0], the compressed liquid type. Recently saw a video (in German, [1]) in which there was back-of-the-envelope calculation that a gravity battery built by hydraulically raising a cylindrical landmass with 1km diameter by 500 meters stores about 2TWh (recent yearly gross electricity consumption of Germany is 560TWh). It's such a simple concept! Also, they are looking for investors: https://heindl-energy.com/ https://heindl-energy.com/ [0] https://en.wikipedia.org/wiki/Gravity_battery https://en.wikipedia.org/wiki/Gravity_battery [1] https://youtube.com/watch?v=pnomwGCBNAE https://youtube.com/watch?v=pnomwGCBNAE

AndrewDucker 4y ago
That is an obscenely large cylinder. And a large height to raise it!
amalcon 4y ago
Pumped-storage hydro (the cheapest and generally most practical gravity battery) is currently responsible for almost all grid-scale energy storage worldwide. I don't think it's fair to say it's not getting attention. What's not getting attention is the use of solids for this. The main reasons are that you'd like to re-use most of the infrastructure of the hydroelectric dam you wanted anyway, and that liquids make for simpler engineering in these cases.
- toss1 4y ago
  What is interesting about a quick look at the Heindl Energy solution is that it looks like basically pumped hydro. The difference is that the water is sitting in a large cylindrical space underground with a large (minimum 100m / 300ft diameter) rock piston sitting on top of the water. Eliminates the need for mountainous terrain with a high lake-like geometry to pump the water up out of the gravity well — they can build this in the flatlands
- narrator 4y ago
  I just had a wonderful and possibly stupid idea. How about pumped hydro with a huge storage tank on the surface and then another huge one at the bottom of a cavern made by an underground nuke test? The main problem of course is that the underground cavern is in the middle of nowhere and radioactive. Maybe you could remediate the pollution in the cavern by filtering the actinides while pumping the water around?
acc_297 4y ago
There are simpler technologies that already exist on this principle pumped hydro being the main one this proposal seems like overkill to have so much storage in a single location
- RGamma 4y ago
  Well of course you can divide up the mass and build several smaller installations. I was merely hinting at the fact that pumped hydro storage can be made more compact and flexible by compressing the liquid with a piston.
mgsouth 4y ago
I'm assuming it's a cylinder 500 m tall, lifted by 500 m so it almost clears the hole (assuming basalt at 2.9 g/cm^3, that's only 1.6 TWh, but close enough.) Watching a 1 km-wide 150-story structure rise from a hole and then disappear would certainly be a majestic sight. However, a few issues: - The Mir mine, 4th deepest open-pit mine in the world, has roughly these dimensions (1,200 m wide x 525 m deep) [1]. Of course, its approximately a cone, so its total volume would be about half the proposed cylinder. The mine took 40 years to excavate, albiet in very harsh conditions. - Simply removing the rock from the hole, with 100% efficiency, would expend 1 TWh of energy (average lift 1/2 of total height). If diesel powered construction equipment is used, theoretical maximum efficiency of just the engines is 50%, realistic is more like 20%. I'd be surprised if you could get a total efficiency of over 1 or 2%. - Of course, you'd also spend energy moving the overburden away from the hole. If the angle of repose was 1-in-5, then the pile would be roughly 150 m (45 stories) at the tallest point, and form a circle 4 km wide centered around the hole. - You could be clever, and just dig out the circumference and bottom of the cylinder. At the bottom every square meter would have 500 meters of rock sitting on top of it. That's 1.5 million kg, or 14,000 kPa (2,000 PSI). That doesn't sound... impossible... but it would require a dense forest of supports. It would be the world's most expensive room-and-pillar mine [2], by several orders of magnitude. Integrity of the rock would be a problem, too. A fault wouldn't just risk a tunnel wall blow-out or cave in, it could litteraly drop a 500 meter mountain on your head. - Speaking of pressure... how do you perfectly maintain the integrity of a 3 km circumference piston ring? The water is going to really, really want to slip past the rock piston. Anywhere it does it will have very serious erosion. How do you fix a problem? Picture one of those submarine movies with water spraying everywhere, but unable to shut it off. - Speaking of pressure, again... how do you maintain the integrity of the rock? You'd have to girdle it in a 3 km x 500 m tall wall. - You still need a very large water reservoir. [1] https://en.wikipedia.org/wiki/Mir_mine https://en.wikipedia.org/wiki/Mir_mine [2] https://en.wikipedia.org/wiki/Room_and_pillar_mining https://en.wikipedia.org/wiki/Room_and_pillar_mining
- RGamma 4y ago
  Good clarification. Perhaps it would be better then to build these at smaller scales (as they suggest on their website) ;) In the video this example is chosen to compare it with the area requirements of conventional pumped hydro as well as to show what magnitude of energy storage would be necessary to compensate for fluctuating solar/wind production.