Typical university press release: this technology can revolutionize our energy grid by storing energy in a building’s foundation, because we powered an LED with some tiny cells we made.
Examples like this are outnumbered by "revolutionary" technologies that never left the lab. It's ok to be skeptical about something so early in development. If they're able to scale the technology and make it practical then it will be time to get excited.
Unpopular opinion, most of MIT's research claims are preposterous and can be safely ignored. Their undergraduate education is quite good, but the research output is quite shoddy. The only exception is their computational photography group (Fredo Durand) is pretty legit.
MIT's research output is certainly top notch, but the blame for this breathiness is squarely on the institution's communication office and whoever directs them to constantly put out such fluffy pieces. FWIW they're not the only institution with that particular problem, and it clearly does well to boost their prestige with the general public.
No their research is much better than most. In my field of Robotics, Russ Tedrake, Alberto Rodriguez regularly get out impactful work (and I have a disdain for most work especially the kind Google does).
I think they kind of lost out in Deep Learning to Berkeley and Stanford but they’re slowly building their expertise in it (frankly most of Academia doesn’t compare to industry outputs in Deep Learning so I don’t think it’s that big a deal)
Yeah, so good they were extensively faking their research and demos for a "personal food computer"...and even selling the fucking things to unsuspecting schools. Literally snake oil scamming.
Then there's your robotics team, backed by millions of dollars in free products and "consulting" (ie doing work for them) in sponsorship by defense contractors...beaten by a bunch of high school kids who raided a BoatUSA store and Home Depot to build an underwater robot with bilge pumps and a bunch of PVC pipe.
The most exciting thing to come out of MIT Media Lab in two decades is an alarm clock wrapped in carpet that rolls off your nightstand when it goes off.
MIT is a defense industry thinktank masquerading as a university.
Sadly scams happen in every school, and I think it may only increase in academia moving forward but what’s the issue with their robotics team?
Russ’s student Scott later went on to make Atlas (Boston Dynamics Humanoid) backflip. They were the first to come up with a backflipping quadruped. Alberto’s team won the Amazon pick and place challenge (also demonstrated a robot playing Jenga). Recently Pulkit showed how to rotate any arbitrary object with a dexterous robotic arm. I’d honestly find it hard to name universities better than MITs at robotics
MIT doesn't have research claims, it has professors and graduate students who do research. As an elite institution that is hungry for research grant dollars, it attracts top researchers that often do excellent research but not always.
What human being would even be qualified to judge the research output of a large research university across all fields? A research university is an umbrella under which hundreds of independent teams perform research. You can do journal metrics, but those have a long latency, you are measuring performance 2 to 10 years in the past, and such metrics are not without bias.
If you Ctrl+F "patent" on an article about a technological breakthrough and get no results you can go ahead and close the window. It's not going to be relevant to your life for at least a decade if ever.
I wonder how much of this is due to the fact that the Media Lab sells access to corporations? They need to make their research and patent portfolio seem utterly transformative to justify the hefty subscription fee.
i guess the voltage would be rather low... but current capacity might be enough to melt your drill bit, if you decide to drill hole through both of the electrodes :-D
Ok, TIL that the high capacity of a supercap doesn't translate into a ginormous voltage (Wikipedia: "A supercapacitor [...] is a high-capacity capacitor, with a capacitance value much higher than other capacitors but with lower voltage limits"). Good to know...
Specifically in this case they were limited to less than 1.23V because that's when you start to get water breakdown in the electrolyte solution (if I've read it right).
Current kills. If your foundation cracks, say, in an earthquake, the electrodes can become exposed. Flooding is also common in earthquakes. As another poster said, floor is lightning.
Harnessing the entropic properties of bulk matter, easily ending up with molecular self assembly, without the need for micromanaging the process--genius!
The team calculated that a block of nanocarbon-black-doped concrete that is 45 cubic meters (or yards) in size — equivalent to a cube about 3.5 meters across — would have enough capacity to store about 10 kilowatt-hours of energy, which is considered the average daily electricity usage for a household. Since the concrete would retain its strength, a house with a foundation made of this material could store a day’s worth of energy produced by solar panels or windmills and allow it to be used whenever it’s needed. And, supercapacitors can be charged and discharged much more rapidly than batteries.
What I'm wondering is how to create a lightning battery with this? Unless my math is wrong (probably is) 1 lightning strike is
1 zeus = 1 billion joules = 300 kwh.
1 big-cube = 45m^3 = 10 kwh
density = 10/45 kwh/m^3
volume needed to bottle lightning = 300kwh * 45/10m^3/kwh = 1350m^3
cube of sides 12m. or sphere of diameter 14m
So, what I'm proposing is, we get a 60m high copper pole, stick it in a 14m diameter sphere of this, and put it in a rainstorm.
Lighting rods are actually there to discharge without lighting.
In any case 10kWh worth of li-ion batteries is about the size of a water cooler tank, so the whole system - bms, inverter and all - is no larger than a water cooler.
For 2 m^3 of the material you will need around 1 metric ton of cement. You need around 2.8 GJ to produce 1 t of cement.
Therefore you need 63 GJ or 17500 kWh to produce a capacitor of 45 m^3 that can hold 10 kWh. (Omitting the 3% carbon in the mixture obv.) I hope the thing is really resistant and cycles forever without degradation.
BTW cement production contributes substantial amounts to global carbon emissions.
In fairness, I think the idea is that you would create this from concrete structures that would be built regardless and used in other ways. Adding extra capacity to the grid for "free" would good.
Of course, this is a press release and they usually consist entirely of breathless exaggerations and wilful omissions of limitations.
Is your math accounting for the volume the added water occupies? The paper describes using excess water for deliberately creating voids the electrolyte can access.
AIUI when mixing cement any excess water in the initial mix weakens the cured product by leaving voids behind. You end up with a less dense cured result. Usually when you mix cement it's a balancing act of using as little water as possible while maintaining workability and still having sufficient water to kick off the process. Then once it sets up you go crazy with the water keeping it hydrated while it cures.
This stuff is deliberately being mixed very wet...
It could still be well within the required compressive strength for things like foundations...
But it's unclear to me how you'd get enough electrical capacity in such mixed applications since concrete is mostly aggregate (rock, gravel, sand), not cement, by volume.
I think those areas of the MIT press release are just fantasy.
45 m3 wall volume is enough for a small single detached home even not counting the cellar or foundation. 10 kWh battery for a solar roof is also often large enough for single family. Having a battery that is not a huge hazard in case of a fire is also valuable. Sounds attractive to me.
Seems to me that the potential of simply lifting a weight up (storage) and down (generation) beats these fancy engineering goals for cost and practicality. Especially if the weight being lifted is a container full of rocks. At first glance there are plenty of those everywhere. No hills or reservoirs needed either.
Of course, no papers need to be published ... that may be the goal.
To estimate the cost and practicality, assume you build a tower 120 meters tall and machinery able to lift 60 tons block of concrete to the top, then retrieve the stored energy by lowering it to the ground level. Think for a moment how much that would cost. Then calculate: mgh = 60000kg x 120m x 10m/s^2 (assume acceleration of gravity is 10m/s^2 for simplicity, no energy losses due to friction etc). The result is 72 million joules. That is 20 kilowatt-hours, about two days of a single household electricity usage.
I love comments like the one above yours "just do this eyesore/expensive/impractical thing instead!"
Good enough is good enough. There is no one size fits all, and we really need to start leveraging everything we can to tackle energy storage. Each thing used doesn't need to be perfect for energy density, it just has to be good enough.
> assume you build a tower 120 meters tall.
vs sticking a concrete block in the ground like this paper is proposing.
As long as the durability is there, and it scales up like they say, this concrete block thing has interesting practical potential, because concrete is so ubiquitous. It's in foundations, it's in walls, it's in floors, it's under the road, sidewalk etc.
Heck, where I live we could turn our whole street in to one big battery to service the neighbourhood, while we couldn't possibly stick a whopping great big tower with concrete blocks in it, or a suitable size water tower.
All right, now assume making a 120m deep hole is cheaper than building a 120m tower. BTW, how many 120m deep holes have you seen in your life? You seem to be expert at them.
I have seen a few 120m towers. They call them skyscrappers.
Anyway, all this for 20Kwh. I can get a Nissan Leaf with a 40/60Kwh battery for way less than a skyscrapper. Most likely for way less than what it costs to make a 120m deep hole.
Long story short: cranes and concrete don't make a practical battery, but they make for many articles and publications.
Before you say "but lithium is hard to find, and concrete isn't": you can also make lead batteries, and ni/cd batteries, and liquid air batteries too. I don't expect the Earth to run out of air in the next decades.
Sorry, I guess I'm coming across wrongly somehow? I think 120m towers are crap as an energy storage solution. Maybe they could shove them inside skyscrapers that are being built, but that seems like a reach, especially given the size of the blocks needed for things to be practical. Leveraging existing mine shafts for it seems relatively sane. The work is done, it's unused, might as well get some ongoing value out of it, vs building a whole sodding great tower.
Static concrete being able to store power like a battery, like the article is talking about, is ideal if it works (possibly with caveats depending on how quickly it degrades). It's a ubiquitous material, used all over the place. It'd be getting value out of something that is going to be used anyway.
Gravity batteries are practical if you don't have to construct most of the infrastructure. Examples would include a bunch of mountains already there to construct a dam and have hydro pump storage, or an unusually nice and straight mine shaft that was already paid by the mine.
Anything heavy can be used as a gravity battery. Water in hydro pump for example. Or lead, or concrete. Lead is not that cheap, concrete is not that effective. For water we usually have already constructed a dam, it's just a case of adding another pipe and a pump.
But I guarantee you that if we were to construct a dam, pipe and pump just for energy storage - instead of taking an already existing dam we built for another reason, it would also not be as good as a bunch of batteries in pretty much all relevant factors.
Or you could avoid building the machinery and just pump water up and down. Then to lower the cost you could drop the tower idea and use a natural hill with reservoir on top. Surprise, surprise you just invented a pumped-storage power station.
Pumped hydro is great, but there are relatively few geographic areas where the terrain is suitable. You need a valley that can be dammed to fill a reservoir, enough water that it actually becomes a reservoir, and then a gentle enough slope coming out of the dam that you can build a secondary reservoir with enough water to capture the outflow of whatever period of time you're storing the energy and pump it back in.
California is one potential location, and there's been a lot of interest in pumped hydro from the California Department of Energy (and utilities), but I doubt it'd work as well nationwide.
I recalled a company doing exactly that design (but 60m high), EnergyVault - I think they also had mineshaft-based projects too. The cranes stack the weights, so there's a lot more than one weight.
Checking their site, I see they currently have a 100MWh storage under construction in china, with a different, boxy-building design. No idea on costs. https://www.energyvault.com/project-cn-rudong
I think the more popular approach is to use a deep hole, like a mine shaft. Maybe depth measured in kms. Because you're suspending from above you might be able to get a bit heavier than 60 tons.
It isn't. Even with pumping water up hill and letting it flow down, which is far easier and more efficient, there just isn't the land, elevation, and water for the scale we need.
This is one of those sort-of hyperbolic put downs which goes to "we need" encompassing the entire western worlds power requirements.
No, you can't replace all existing power sources now and into the future by pumped hydro.
Pumped hydro has a massive role to play in power supply, time shifting electricity from renewable sources, providing system resiliency, black start, inductive and inertial load, you-name-it. It also exists. It's in widespread use, across the globe. I have one less than 100km from me here in Qld, there is one under construction in the snowy hydro project (with issues) complementing an existing unit at Tumut, Another at Shoalhaven in NSW and there are two large sites in the UK power grid Dinorwig and Cruachan, both of which supply near-instantaneous (<20sec) power against demand shifts.
Compared to gas turbine load start (minutes), pumped hydro is fast (seconds). Compared to batteries (milliseconds), It's slow. Batteries have capacity limits too. In the capacity stakes, Pumped hydro can beat them hands-down but for a massive initial capital outlay. Snowy 2.0 will supply DAYS of power. 2Gigawatts, as 350GWh of power. 3 million homes equivalent, for a week. People argue about the economics, not about the underlying capability.
Worldwide there are plenty of good sites, including mine shafts. And, gravity models for power include trains, and cranes. Neither of which will replace all sources of power for all burdens in the network either. The idea this is limited to existing land-surface bodies of water simply isn't true.
Not all useful things have to be able to solve the problems "at the scale we need" to be both useful, and able to solve problems.
I’ve always wanted to ask someone who knew something about this stuff if this idea is feasible:
Imagine a giant empty bucket held high in the air. As it rains, the bucket fills and using a counter-weight it slowly lowers down to ground level. Now the bucket is covered and the water is slowly drained causing the counter-weight to lower to the ground and the bucket to rise in the air again.
If this were geared properly, could energy be generated in any meaningful amount?
No at all. No one is suggesting it must cover all power needs. Sure, there may be municipalities that are advantaged by it due to the unique and perfect nature of their geography. But that's not going to be enough to put any realistic dent in the problem at a national level.
People in general demand quick, simple, easy and singular solutions to complex problems that cover massive ranges of financial, geographical, political, cultural, and individual variances with no tolerance, and they honestly believe they are being fair and reasonable when they do so.
Example:
Idea: "New houses could have cheap batteries built into their foundations, cheaply decreasing the load on the electrical grid and providing a backup source to cover temporary power outages."
Response: "Well, that's not going to completely solve the energy crisis, restore CO2 to pre-industrial revolution levels and avert the polar ice caps from melting, so what's the point?"
Building the contraption that carries weights is not feasible. Worse yet, if you have to pay for the weights, then your idea needs to be thrown out entirely because you will never recoup the cost of a manufactured weight.
That only works for relatively small amounts of (potential) energy, not grid-scale; the best / most efficient form of that is pumping water up into an elevated lake, that's the scalable version. But it's limited by availability of elevation and whatnot.
This is already used in many places, due to the very low cost, but the amount of energy stored in a given volume is very small in comparison with batteries or supercapacitors, even when a great difference in height is available.
While I love the ingenuity of this system, I have some trouble seeing it used as an economically viable energy storage option. According to the article, they would need about 45 m3 to store 10 kwh. At a concrete price of 200-300 $/m3, that would come to 9-13.5k USD just for the concrete. That's omitting any costs for the carbon black electrolyte, material processing, electrolyte separators and other things, so a very optimistic estimate.
Meanwhile, battery prices have fallen so much that you can buy 10 kwh of Li-Ion batteries for about $1500 ($150/kwh 2021 prices). The saving grace might be to have it do double duty as a structural element in the building, but many other posters have pointed out that there are many safety and construction problems that would have to be solved for that first.
It might also turn out that lime for the concrete will become a rate limiting material. Not to mention the energy cost involved in mining both it and creating the carbon nanopowder.
But, a material with similar hydration properties to concrete, a biopolymer for instance, might exist and be made with less cost...
We actually have to start thinking about replacing concrete with something else to be more energy efficient and sustainable.
Raw concrete price in USA is closer to 150$/m3, often less.
One thing we don’t know is life expectancy vs Li-ion, whose 10-year charge is ~60%.
I haven’t read the paper; one thing that’ll also be interesting is operating temperatures. This could be a massive upside to concrete supercaps in certain parts of the globe.
There is usualy steel reinforcement (rebar) in the concrete. Isn't introducing electrical current gonna cause galvanic corrosion of the rebar? Might even affect concrete structures around the capacitor, not just the capacitor itself.
Also if i understood correctly, this capacitor would need to be kept wet (with water) to remain operational right? Wet basement is extremely annoying thing with many unpleasant consequences to say the least. So this might require some efforts to maintain the moisture while keeping it contained.
How do you replace this thing? Eg. once cracks inevitably form in concrete, or when the carbon structure get damaged by accidental overvoltage/overcurrent, or when the insulation layers deteriorate. You cannot simply replace foundation of a building. Therefore it would make sense to keep the capacitor at least partialy separated from the structural parts of the building.
Anyway this seems as an interresting idea and i wonder if plastic bucket full of concrete would be enough to power something like UPS to provide 100W to keep PC running for 15 minutes. Might as well stop replacing lead acid batteries every other year if this is at least remotely viable.
If it's not the galvanic effect, it would be more direct corrosion as the block will be "soaked in a standard electrolyte material, such as potassium chloride".
And - given that the concrete will be poured "normally" - the reproducibility of these "power foundations" is likely to be low (and as you say there is no easy wayback).
Besides, concrete is not just water and cement, the various sized aggregates (sand, gravel, finer aggregates) are what make it actually "concrete", the "grain" of concrete used in construction is very different from pure cement+water (and 3% carbon) mix, the samples they made (1 mm thick) won't likely scale up.
This may be true, but if it's going to be used for housing foundations regardless (because there aren't competitive alternatives), then it's essentially a sunk cost. The fact that you can get a supercapacitor out of your foundation for very low incremental cost is amazing (assuming they can scale the technology as anticipated).
One thing I wondered about is what happens as the concrete expands/contracts due to weather, or is fractured when it 'settles' (or if there is an earthquake).
Depends on if it can short its charge to ground I guess, and how fast. An uncharged concrete capacitor is of course pretty harmless even if it cracks, so perhaps you could pour some strain gauges into it so you get advance warning of impending problems.
I know nothing of the topic, but this was the type of thing I reflexively wondered about. Hopefully knowledgeable HNers can fill us in on the likely risks or downsides, which are not typically the focus of university press releases.
> The team calculated that a block of nanocarbon-black-doped concrete that is 45 cubic meters (or yards) in size — equivalent to a cube about 3.5 meters across — would have enough capacity to store about 10 kilowatt-hours of energy, which is considered the average daily electricity usage for a household.
Edit: 10kwh/3.5³m³ ≈ 0.233 Wh/l
> Besides its ability to store energy in the form of supercapacitors, the same kind of concrete mixture can be used as a heating system, by simply applying electricity to the carbon-laced concrete.
I would be happy if I have it as a backup power source so I could wear warm clothes make myself hot coffee in electric kettle and wait for grid to be back online.
> Two electrodes made of this material, separated by a thin space or an insulating layer, form a very powerful supercapacitor, the researchers found.
The image of a huge cube is a bit misleading. If you made a huge cube, you'd probably want a sandwich of thin layers separated by thin film, wired in alternating polarity. Not exactly something you could pour in a foundation.
By splitting the cube in 2 :) But that would kind of ruin the press release so it's not mentioned. Also, the paper itself mentions no houses nor foundations nor other shit like that. That's only in the press release.
I presume supercapacitor needs to alternate thin layers of electrode/the cement mix/insulator, not just pour the bulk? It then makes more sense to prefabricate bricks/panels and connect them when laying.
The idea of utilizing materials like water and gelatin to create supercapacitors that can potentially outperform conventional energy storage methods is a testament to human creativity and adaptability.
The first sustained artificial nuclear reaction [1] managed to produce...half a watt. I'm glad they weren't overly cynical about future possibilities.
[1] https://en.wikipedia.org/wiki/Chicago_Pile-1
I think they kind of lost out in Deep Learning to Berkeley and Stanford but they’re slowly building their expertise in it (frankly most of Academia doesn’t compare to industry outputs in Deep Learning so I don’t think it’s that big a deal)
Yeah, so good they were extensively faking their research and demos for a "personal food computer"...and even selling the fucking things to unsuspecting schools. Literally snake oil scamming.
https://www.google.com/search?client=firefox-b-1-d&q=MIT+med...
Then there's your robotics team, backed by millions of dollars in free products and "consulting" (ie doing work for them) in sponsorship by defense contractors...beaten by a bunch of high school kids who raided a BoatUSA store and Home Depot to build an underwater robot with bilge pumps and a bunch of PVC pipe.
The most exciting thing to come out of MIT Media Lab in two decades is an alarm clock wrapped in carpet that rolls off your nightstand when it goes off.
MIT is a defense industry thinktank masquerading as a university.
Russ’s student Scott later went on to make Atlas (Boston Dynamics Humanoid) backflip. They were the first to come up with a backflipping quadruped. Alberto’s team won the Amazon pick and place challenge (also demonstrated a robot playing Jenga). Recently Pulkit showed how to rotate any arbitrary object with a dexterous robotic arm. I’d honestly find it hard to name universities better than MITs at robotics
What human being would even be qualified to judge the research output of a large research university across all fields? A research university is an umbrella under which hundreds of independent teams perform research. You can do journal metrics, but those have a long latency, you are measuring performance 2 to 10 years in the past, and such metrics are not without bias.
of q^2/2C
The team calculated that a block of nanocarbon-black-doped concrete that is 45 cubic meters (or yards) in size — equivalent to a cube about 3.5 meters across — would have enough capacity to store about 10 kilowatt-hours of energy, which is considered the average daily electricity usage for a household. Since the concrete would retain its strength, a house with a foundation made of this material could store a day’s worth of energy produced by solar panels or windmills and allow it to be used whenever it’s needed. And, supercapacitors can be charged and discharged much more rapidly than batteries.
What I'm wondering is how to create a lightning battery with this? Unless my math is wrong (probably is) 1 lightning strike is
So, what I'm proposing is, we get a 60m high copper pole, stick it in a 14m diameter sphere of this, and put it in a rainstorm.Bottle of lightning?
In any case 10kWh worth of li-ion batteries is about the size of a water cooler tank, so the whole system - bms, inverter and all - is no larger than a water cooler.
A week later there were already ChatGPT-generated posts in English, German and Russian.
Well, at least the client got a demonstration regarding the consequences of having weak passwords.
I've filled the form you gotta fill in such situations, but I'm not hopeful I'll ever get this domain back.
Shame, because this started out as CV padding but over time evolved into this one place I link people to for quick solutions to stuff.
Therefore you need 63 GJ or 17500 kWh to produce a capacitor of 45 m^3 that can hold 10 kWh. (Omitting the 3% carbon in the mixture obv.) I hope the thing is really resistant and cycles forever without degradation.
BTW cement production contributes substantial amounts to global carbon emissions.
Of course, this is a press release and they usually consist entirely of breathless exaggerations and wilful omissions of limitations.
AIUI when mixing cement any excess water in the initial mix weakens the cured product by leaving voids behind. You end up with a less dense cured result. Usually when you mix cement it's a balancing act of using as little water as possible while maintaining workability and still having sufficient water to kick off the process. Then once it sets up you go crazy with the water keeping it hydrated while it cures.
This stuff is deliberately being mixed very wet...
But it's unclear to me how you'd get enough electrical capacity in such mixed applications since concrete is mostly aggregate (rock, gravel, sand), not cement, by volume.
I think those areas of the MIT press release are just fantasy.
Of course, no papers need to be published ... that may be the goal.
Good enough is good enough. There is no one size fits all, and we really need to start leveraging everything we can to tackle energy storage. Each thing used doesn't need to be perfect for energy density, it just has to be good enough.
> assume you build a tower 120 meters tall.
vs sticking a concrete block in the ground like this paper is proposing.
As long as the durability is there, and it scales up like they say, this concrete block thing has interesting practical potential, because concrete is so ubiquitous. It's in foundations, it's in walls, it's in floors, it's under the road, sidewalk etc.
Heck, where I live we could turn our whole street in to one big battery to service the neighbourhood, while we couldn't possibly stick a whopping great big tower with concrete blocks in it, or a suitable size water tower.
I have seen a few 120m towers. They call them skyscrappers.
Anyway, all this for 20Kwh. I can get a Nissan Leaf with a 40/60Kwh battery for way less than a skyscrapper. Most likely for way less than what it costs to make a 120m deep hole.
Long story short: cranes and concrete don't make a practical battery, but they make for many articles and publications.
Before you say "but lithium is hard to find, and concrete isn't": you can also make lead batteries, and ni/cd batteries, and liquid air batteries too. I don't expect the Earth to run out of air in the next decades.
Static concrete being able to store power like a battery, like the article is talking about, is ideal if it works (possibly with caveats depending on how quickly it degrades). It's a ubiquitous material, used all over the place. It'd be getting value out of something that is going to be used anyway.
Anything heavy can be used as a gravity battery. Water in hydro pump for example. Or lead, or concrete. Lead is not that cheap, concrete is not that effective. For water we usually have already constructed a dam, it's just a case of adding another pipe and a pump.
But I guarantee you that if we were to construct a dam, pipe and pump just for energy storage - instead of taking an already existing dam we built for another reason, it would also not be as good as a bunch of batteries in pretty much all relevant factors.
California is one potential location, and there's been a lot of interest in pumped hydro from the California Department of Energy (and utilities), but I doubt it'd work as well nationwide.
Checking their site, I see they currently have a 100MWh storage under construction in china, with a different, boxy-building design. No idea on costs. https://www.energyvault.com/project-cn-rudong
I think the more popular approach is to use a deep hole, like a mine shaft. Maybe depth measured in kms. Because you're suspending from above you might be able to get a bit heavier than 60 tons.
No, you can't replace all existing power sources now and into the future by pumped hydro.
Pumped hydro has a massive role to play in power supply, time shifting electricity from renewable sources, providing system resiliency, black start, inductive and inertial load, you-name-it. It also exists. It's in widespread use, across the globe. I have one less than 100km from me here in Qld, there is one under construction in the snowy hydro project (with issues) complementing an existing unit at Tumut, Another at Shoalhaven in NSW and there are two large sites in the UK power grid Dinorwig and Cruachan, both of which supply near-instantaneous (<20sec) power against demand shifts.
Compared to gas turbine load start (minutes), pumped hydro is fast (seconds). Compared to batteries (milliseconds), It's slow. Batteries have capacity limits too. In the capacity stakes, Pumped hydro can beat them hands-down but for a massive initial capital outlay. Snowy 2.0 will supply DAYS of power. 2Gigawatts, as 350GWh of power. 3 million homes equivalent, for a week. People argue about the economics, not about the underlying capability.
Worldwide there are plenty of good sites, including mine shafts. And, gravity models for power include trains, and cranes. Neither of which will replace all sources of power for all burdens in the network either. The idea this is limited to existing land-surface bodies of water simply isn't true.
Not all useful things have to be able to solve the problems "at the scale we need" to be both useful, and able to solve problems.
Imagine a giant empty bucket held high in the air. As it rains, the bucket fills and using a counter-weight it slowly lowers down to ground level. Now the bucket is covered and the water is slowly drained causing the counter-weight to lower to the ground and the bucket to rise in the air again.
If this were geared properly, could energy be generated in any meaningful amount?
Many people have done the math.
https://dothemath.ucsd.edu/2011/11/pump-up-the-storage/
People in general demand quick, simple, easy and singular solutions to complex problems that cover massive ranges of financial, geographical, political, cultural, and individual variances with no tolerance, and they honestly believe they are being fair and reasonable when they do so.
Example:
Idea: "New houses could have cheap batteries built into their foundations, cheaply decreasing the load on the electrical grid and providing a backup source to cover temporary power outages."
Response: "Well, that's not going to completely solve the energy crisis, restore CO2 to pre-industrial revolution levels and avert the polar ice caps from melting, so what's the point?"
And they think that this response is rational.
Meanwhile, battery prices have fallen so much that you can buy 10 kwh of Li-Ion batteries for about $1500 ($150/kwh 2021 prices). The saving grace might be to have it do double duty as a structural element in the building, but many other posters have pointed out that there are many safety and construction problems that would have to be solved for that first.
But, a material with similar hydration properties to concrete, a biopolymer for instance, might exist and be made with less cost...
We actually have to start thinking about replacing concrete with something else to be more energy efficient and sustainable.
One thing we don’t know is life expectancy vs Li-ion, whose 10-year charge is ~60%.
I haven’t read the paper; one thing that’ll also be interesting is operating temperatures. This could be a massive upside to concrete supercaps in certain parts of the globe.
Also if i understood correctly, this capacitor would need to be kept wet (with water) to remain operational right? Wet basement is extremely annoying thing with many unpleasant consequences to say the least. So this might require some efforts to maintain the moisture while keeping it contained.
How do you replace this thing? Eg. once cracks inevitably form in concrete, or when the carbon structure get damaged by accidental overvoltage/overcurrent, or when the insulation layers deteriorate. You cannot simply replace foundation of a building. Therefore it would make sense to keep the capacitor at least partialy separated from the structural parts of the building.
Anyway this seems as an interresting idea and i wonder if plastic bucket full of concrete would be enough to power something like UPS to provide 100W to keep PC running for 15 minutes. Might as well stop replacing lead acid batteries every other year if this is at least remotely viable.
And - given that the concrete will be poured "normally" - the reproducibility of these "power foundations" is likely to be low (and as you say there is no easy wayback).
Besides, concrete is not just water and cement, the various sized aggregates (sand, gravel, finer aggregates) are what make it actually "concrete", the "grain" of concrete used in construction is very different from pure cement+water (and 3% carbon) mix, the samples they made (1 mm thick) won't likely scale up.
A potential downside is the predominant production methods for cement aren't great for the climate.
One thing I wondered about is what happens as the concrete expands/contracts due to weather, or is fractured when it 'settles' (or if there is an earthquake).
Edit: 10kwh/3.5³m³ ≈ 0.233 Wh/l
> Besides its ability to store energy in the form of supercapacitors, the same kind of concrete mixture can be used as a heating system, by simply applying electricity to the carbon-laced concrete.
Excluding heating.
The image of a huge cube is a bit misleading. If you made a huge cube, you'd probably want a sandwich of thin layers separated by thin film, wired in alternating polarity. Not exactly something you could pour in a foundation.
I presume supercapacitor needs to alternate thin layers of electrode/the cement mix/insulator, not just pour the bulk? It then makes more sense to prefabricate bricks/panels and connect them when laying.
Maybe dams could store excess energy in their structure.
Worst case, the battery function drops to unusable levels and then you just have a plain old house foundation.