Been hearing about this project for years, nice to see that it's gaining traction! Only question is that if they use captured Co2 initially or if they have to produce it.
CO2 batteries that store grid energy take off globally
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Re: CO2 batteries that store grid energy take off globally
#92No mention of round-trip efficiencies, and claims are that it's 30% cheaper than Li-Ion. Which might give it an advantage for a while, but as Li-Ion has become 80% cheaper in the last decade that's not something which will necessarily continue. Great if it can continue to be cheaper, of course. Fingers crossed that they can make it work at scale.
AFAIK cost here counts only the manufacturing side. While your conclusion that in the long run economies of scale will prevail, the lifetime costs are probably more than 30%. For example I expect recycling costs to be significantly worse for the Li-Ion.
> For example I expect recycling costs to be significantly worse for the Li-Ion.
I think there's a good argument for the opposite.
Recycling costs for Li-Ion once we are doing it at scale should be significantly negative. There are valuable materials you get to extract, they aren't in that complex a blend to extract them from, and there's a lot of basically the same blend. The biggest risk in this claim is, I think, the implicit claim that we won't figure out how to extract the same materials from the earth much cheaper in the meantime cratering the end of life value of batteries - but in that event the CO2 battery technology is underwater anyways and the chemical batteries win on not wasting R&D costs.
By contrast while there's some value in the steel that goes into building tanks and pumps and so on, the material cost if a much lower fraction of the cost of the device. Most of the cost went into shaping it into those complex shapes. I don't know for sure what the cost breakdown of the CO2 plant looks like but if a lot of the cost is something else it's probably something like concrete or white paint that actually costs money to dispose of.
Re: CO2 batteries that store grid energy take off globally
#93They never mention what advantage CO2 has over any other gas, like plain air?
Re: CO2 batteries that store grid energy take off globally
#94Does pure-ish CO2 have advantages over regular air or the freon-like substance used in air conditioning? How much energy us used to purify and maintain the CO2?
These days CO2 is actually quite commonly used in air-conditioners as a refrigerant, R-744. Fluorinated gases like Freon are being phased out due to being even worse for global warming.
I thought it was ozone depletion, not greenhouse effects, that led to the fluorinated gas phaseout?
Re: CO2 batteries that store grid energy take off globally
#95> And in 2026, replicas of this plant will start popping up across the globe.
> We mean that literally. It takes just half a day to inflate the bubble. The rest of the facility takes less than two years to build and can be done just about anywhere there’s 5 hectares of flat land.
Gotta love the authors comitment to the bit. Wow, only half a day you say? And then just between 1 to 2 years more? Crazy.
Re: CO2 batteries that store grid energy take off globally
#96"First, a compressor pressurizes the gas from 1 bar (100,000 pascals) to about 55 bar (5,500,000 pa). Next, a thermal-energy-storage system cools the CO2 to an ambient temperature. Then a condenser reduces it into a liquid that is stored in a few dozen pressure vessels, each about the size of a school bus. The whole process takes about 10 hours, and at the end of it, the battery is considered charged. To discharge th…
And I suppose the whole thing is a closed system? Which means, none of the CO2 would be released to the outside?
Yes. If the CO2 was just released you would have to pay the energy cost to extract it from the atmosphere again.
Re: CO2 batteries that store grid energy take off globally
#97We don't need another few-hours storage technology. Batteries are going to clobber that. What we need is a storage technology with a duration of months. That would be truly complementary to these short term storage technologies.
I don't understand. Why is a duration of months preferable? What is the benefit above storing energy beyond say peak-to-peak? I suppose you can flatten out seasonal variation, but that's not nearly as big of a problem.
Re: CO2 batteries that store grid energy take off globally
#98Earlier quoted context omitted.
The last section of TFA is called "What happens if the dome is punctured?". The answer: a release of CO2 equal to about 15 transatlantic flights. People have to stand back 70m until it clears. It would not be good, but it wouldn't be Bhopal. And there are still plenty of factories making pesticides.
> People have to stand back 70m until it clears. How did they calculate that evacuation distance? CO2 is heavy. That little house about 15m from the bubble needs to be acquired. The topography matters. If the installation is in a valley, a dome rip could make air unbreathable, because the CO2 will settle at the bottom. People have been killed by CO2 fire extinguishing systems. It takes a reasonably high concentration…
The distance is likely calculated based on the stored volume and the area you cover until the height is significantly below head height (because as you point out CO2 settles to the bottom). Regarding the little house 15m from the bubble, they are not planning to build this in residential areas, so it's very unlikely that there would be a house within 15m just for operational purposes already.
Re: CO2 batteries that store grid energy take off globally
#99Earlier quoted context omitted.
I'm seeing round trip efficiencies around 75%. That's not terrible. These things would probably pair well with district heating and cooling.
That is shockingly good. EIA reports existing grid scale battery round trip is like 82% which do not have moving parts. ...in 2019, the U.S. utility-scale battery fleet operated with an average monthly round-trip efficiency of 82%, and pumped-storage facilities operated with an average monthly round-trip efficiency of 79%.... https://www.eia.gov/todayinenergy/detail.php?id=46756
> existing grid scale battery round trip is like 82% which do not have moving parts.
This is incorrect for a lot of containerized lithium systems. They have a lot of moving parts in their AC systems - the compressors, the fans, the cooling water pumps.
Lithium cells really don't like to be hot. If you put them next to solar farms in the sun belt or if you discharge them moderately quickly, you'll have to cool them. This cooling system also eats into the overall efficiency, but what's even worse is that its the majority of the maintenance budget.
Re: CO2 batteries that store grid energy take off globally
#100They never mention what advantage CO2 has over any other gas, like plain air?
The fluid in high pressure storage is a liquid, making the storage much cheaper. Liquid N2 (most of air) would require over 40 times more pressure or cold temperatures. Purifying out CO2 or any gas is generally a negligible cost.