I would expect it would be pretty similar, in each case you’re lifting a mass to create some potential energy and then draining it later. I can’t imagine the work involved in pumping up water is all that different in terms of efficiency from lifting concrete. The advantage with concrete is that you can do it in places where you don’t have huge amounts of water to spare though.
Yeah, emergency water reservoir isn’t a bad thing to have. Not a first choice but less reliable powergrid is worth taking if it is the alternative to not having water.
I mean, unless they’re directly cutting up old buildings into the final block shape for this (which would be a nightmare to actually do), it doesn’t actually help that much. You can’t practically un-make concrete and turn it back into that slurry that comes out of the mixer truck, AFAIK all “recycled” concrete means is old concrete gets crushed into fragments and used in place of gravel. But the gravel is not the truly problemic part, you still need more cement to bind those fragments into your desired shape, which releases carbon and consumes water.
On the topic, I really doubt it’s about savings at this scale, which is very much proof of concept. I mean it could be but at this stage it’s more important to show it’s potential. And for some thing that’s gonna run for thousands of cycles…
I mean, it’s not like concrete is scraping on the walls going up and down, it’s on a pulley system which would be efficient in terms of doing energy transfer. The article mentions round-trip efficiency above 80 percent, so I’m not sure pumping water could be much more efficient than that.
The main problem with gravitational storage is that it is incredibly weak compared to chemical, compressed air, or flywheel techniques (see the post on home energy storage options). For example, to get the amount of energy stored in a single AA battery, we would have to lift 100 kg (220 lb) 10 m (33 ft) to match it. To match the energy contained in a gallon of gasoline, we would have to lift 13 tons of water (3500 gallons) one kilometer high (3,280 feet). It is clear that the energy density of gravitational storage is severely disadvantaged.
It seems the problem is not necessarily one of conversion efficiency, but rather of scale. In order to store significant amounts of electrical energy using mechanical means, you need to move a lot of weight. Manufacturing the concrete blocks requires money and raw materials, and a pulley system robust enough to move them around wouldn’t be cheap either. The pumped storage hydroelectric systems which currently provide the vast majority of our grid energy storage partially circumvent this expense by taking advantage of natural bodies of water and advantageous topography.
That being said, it’s definitely a fascinating concept and one worth exploring. But there are well established difficulties that explain why this type of energy storage isn’t already widespread.
Well, this 80% efficiency is what they are targeting not what the system will do.
The test system Energy Vault build in a MUCH smaller form factor had a round-trip efficency of 75%
The EVx ™ system is projected to achieve an impressive round-trip efficiency exceeding 80%. Source
Only time will tell if they can reach 80% with a bigger system or at all. If they actually manage this it would be a decent alternative to Hydrodams in areas where these are just not possible since it would be a similar round-trip efficency.
Pumped storage systems have a round-trip efficiency of about 80%, which is competitive with battery storage. Source
In my opinion these systems are inferior to fly wheel energy storage (can reach up to 90% round trip efficency
Source) but might still be an option depending on price.
Sorta curious how this compares to pumped hydro with a giant water tower - or a deep pit and store the water at ground level.
I would expect it would be pretty similar, in each case you’re lifting a mass to create some potential energy and then draining it later. I can’t imagine the work involved in pumping up water is all that different in terms of efficiency from lifting concrete. The advantage with concrete is that you can do it in places where you don’t have huge amounts of water to spare though.
Water is way, way cheaper, and concrete requires a massive amount of water.
Just saying.
Water also doesn’t get damaged through constantly moving it.
Thats a pretty fucking big on. Also, the technology to “turn a wheel” to create electricity… pretty fucking established.
And… god forbid, if the community you are in ends up needing water more than electricity, well, you’ve got a bunch stored and ready for other uses.
Yeah, emergency water reservoir isn’t a bad thing to have. Not a first choice but less reliable powergrid is worth taking if it is the alternative to not having water.
the article says it’s recycled though…
I mean, unless they’re directly cutting up old buildings into the final block shape for this (which would be a nightmare to actually do), it doesn’t actually help that much. You can’t practically un-make concrete and turn it back into that slurry that comes out of the mixer truck, AFAIK all “recycled” concrete means is old concrete gets crushed into fragments and used in place of gravel. But the gravel is not the truly problemic part, you still need more cement to bind those fragments into your desired shape, which releases carbon and consumes water.
I mean I would guess it’s for energy density not environmental savings of any kind.
I would guess it’s because it’s likely very low cost and easy to build, but there are obvious environmental savings that fall out of it naturally.
sigh… Buh dim tish.
On the topic, I really doubt it’s about savings at this scale, which is very much proof of concept. I mean it could be but at this stage it’s more important to show it’s potential. And for some thing that’s gonna run for thousands of cycles…
High friction is my guess.
I mean, it’s not like concrete is scraping on the walls going up and down, it’s on a pulley system which would be efficient in terms of doing energy transfer. The article mentions round-trip efficiency above 80 percent, so I’m not sure pumping water could be much more efficient than that.
https://dothemath.ucsd.edu/2011/11/pump-up-the-storage/
It seems the problem is not necessarily one of conversion efficiency, but rather of scale. In order to store significant amounts of electrical energy using mechanical means, you need to move a lot of weight. Manufacturing the concrete blocks requires money and raw materials, and a pulley system robust enough to move them around wouldn’t be cheap either. The pumped storage hydroelectric systems which currently provide the vast majority of our grid energy storage partially circumvent this expense by taking advantage of natural bodies of water and advantageous topography.
That being said, it’s definitely a fascinating concept and one worth exploring. But there are well established difficulties that explain why this type of energy storage isn’t already widespread.
right, it only makes sense if you do it at large scale
What about friction within the pulley?
Again, they state over 80% efficiency in the article. So, that’s your answer.
Well, this 80% efficiency is what they are targeting not what the system will do. The test system Energy Vault build in a MUCH smaller form factor had a round-trip efficency of 75%
Only time will tell if they can reach 80% with a bigger system or at all. If they actually manage this it would be a decent alternative to Hydrodams in areas where these are just not possible since it would be a similar round-trip efficency.
In my opinion these systems are inferior to fly wheel energy storage (can reach up to 90% round trip efficency Source) but might still be an option depending on price.