New Breakthrough in Energy Storage – MIT Engineers Create Supercapacitor out of Ancient Materials::Constructed from cement, carbon black, and water, the device holds the potential to offer affordable and scalable energy storage for renewable energy sources. Two of humanity’s most ubiquitous historical materials, cement and carbon black (which resembles very fine charcoal), may form the basis for
Seems interesting.
A big take away is that you can store a house’s daily use of energy with the equivalent of a 9ft x 9ft cube of the stuff, and since it’s still load bearing concrete, they say you could use it in a house’s foundation without issue, giving basically every house a built in daily battery.
They also talk about integration into the base of wind turbines where they currently just have structure concrete, so this would be a built in energy store.
No where near as energy dense as current batteries, but insanely cheap and ubiquitous, it scales without issue in any direction, and is well suited to “grid style” electrical loads.
Can you put steel reinforcement in it? I didn’t see it mentioned in the article but I could have missed it. Basically any load bearing bit of concrete will have some amount of steel in it to prevent cracking and in heavier structures to add to the strength of the concrete.
Really promising technology though, concrete is basically everywhere so if we can turn it into batteries relatively cheaply that’s absolutely huge.
I doubt it. The carbon acts as the conductor to the cement’s insulator. Adding rebar is likely going to cause issues. I expect this wont have applications in high rises, more akin to a cinder block or poured concrete foundations that wouldn’t need reinforcement.
Might honestly be a fatal flaw for most applications where we currently use concrete, but maybe purpose built devices would still make sense at power plants/etc.
Epoxy coated rebar is already a thing, so insulated rebar shouldn’t be that big of a deal - if epoxy isn’t enough already.
Maybe different for different regions but I’m pretty sure foundations will generally have a small amount of steel mesh at a minimum to stop cracking. Someone please correct me if I’m wrong though and hopefully they find a way around this limitation as well. Carbon fibre can also be used from memory but I haven’t seen it that often presumably due to cost.
Maybe for home foundations and the like, glass fiber rebar could be used.
Why can’t the steel rebar just be part of the conductive carbon anode?
The design already assumes the concrete is riddled with conductive material. Why would adding fat wires hurt?
At a claimed energy density of 0.22kWh/m^3 I think their projection of storing enough for an entire household is overly optimistic.
My whole foundation for a 2 story 200m^2 house is about half the 45m^3 they claim is needed for a household.
Sounds promising but it won’t be replacing batteries any time soon.
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God, i wish my house used 10kwh of power per day. During winter that is more like 20 and during summer it can go as high as 30. We are doing projects to improve that, vut its a slow process with financial constraints.
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I’m surprised that per capita, the absolute worst is Qatar with 3x the consumption of the US. The average US citizen however consumes ~2x as much as a German, Japanese, Iranian, French or Irish citizen.
https://ourworldindata.org/grapher/per-capita-energy-use?tab=table
The data kinda seems off though. How is an Icelandic citizen using 3x as much as a US citizen? Did they completely get rid of fossil fuels or something?
Qatar and Iceland are both rich nations in an inhospitable climate.
Makes sense they’d be near the top in heating/cooling.
Iceland has so much renewables with water and geothermal, they can use it however they want.
Yeah, i feel like the fridge uses that much by itself. Seriously though i have no idea where it all goes.
Yeah, i just looked and the minimum i have used all year is 661kwh which is ~22 per day. The house is 1000 sqft.
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There’s always a hook or some reason why this is optimistic, but I can’t see it yet. They mention foundations and roads, but I’m wondering where else it could used. I don’t think it would make sense to just fill an entire cave with this and “charge” the cave, would it?
Now you won’t just have a crack in your foundation, you’ll have a total loss of power and an open battery with thousands of watts of power ready to arc to any conductive material nearby.
Also, isn’t the biggest issue with super capacitors their discharge rate? A capacitor stores energy very briefly and will dump it extremely quickly into whatever circuit it’s connected to, that doesn’t sound ideal for energy storage over multiple hours or days.
A capacitor can’t ‘dump’ it’s energy any faster than tbe circuit attached to it can use it, as illustrated by Ohm’s law (ignoring the capacitor’s self discharge rate, which for a purpose like this can be kept very low).
With a low self discharge rate there’s also nothing brief about the length of time a capacitor can store energy. Think of it like a bucket with a small leak (self discharge rate). We’re adding water/energy to it each day (from solar panels or similar), and taking some out as needed. As long as the leak is small in comparison to the amount of water/energy being put in it’ll still be well topped up when you need it.
With regard to a crack, it sounds like that will just lead to a reduction in storage capacity to worst, if a chunk actually falls off. The carbon forms a branching network throughout the entire block, so just breaking some strands wont stop it being conductive. You’d definitely want to deplete it before working on it though, even a small cap can give you a nasty whack.
