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CO2 batteries that store grid energy take off globally

spectrum.ieee.org

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Re: CO2 batteries that store grid energy take off globally

#141

Post by andrewflnr »

cycomanic wrote: post #68
SoftTalker wrote: post #50

Earlier quoted context omitted.

Good luck running 70m in a CO2 dense atmosphere. And CO2 hugs the ground it does not float away. It will persist in low areas for quite a while. Anyone in the local vicinity would need to carry emergency oxygen at all times to be able to get to a safe distance in case of rupture. Otherwise it's a death sentence, and not a particularly pleasant one as CO2 is the signal that triggers the feeling of suffocation.

It's unlikely that the thing will burst and disperse all CO2 immediately. It's just slightly higher pressure than the outside (that's the whole principle). So you have a slow leak of CO2 to the outside. You don't have to run that fast (or run at all). The way I understood the quote, the safety distance is when they have to do an emergency deflate (e.g. due to wind). The way they calculate the 70 m is probably based o…

> It's unlikely that the thing will burst and disperse all CO2 immediately.

This requires the people running this facility, and all the facilities based on it built by unrelated organizations in the future, to not cut engineering corners on the envelope. I don't take this for granted anymore. But as long as you don't get a big rip, then yeah, it'll be hard to build up a dangerous amount. I wonder if a legally mandatory cut and repair trial on the envelope would reduce risk significantly.

Speaking of wind, I also worry about whoever is downwind if there's a big release. I bet 70m is not quite far enough if it's in the wrong direction.

Re: CO2 batteries that store grid energy take off globally

#142

Post by SigmundA »

hunter2_ wrote: post #134
SigmundA wrote: post #127

Earlier quoted context omitted.

A watt of power multiplied by a second of time has an agreed upon name called joule, but a watt second is also a perfectly valid SI name. A watt is a joule of energy divided by a second of time, this is a rate, joule per second is also a valid name similar to nautical mile per hour and knot being the same unit. Multiplication vs division, quantity vs rate, see the relationship? Units may have different names but are…

So when I torque all 20 of my car's lug bolts to 120 n-M, I've exerted 2/3 of a W-h? So if it takes me 4 minutes, I'm averaging 10 watts? That's neat. I wonder what the peak wattage (right as the torque wrench clicks) would be; it must depend on angular velocity.

Newton meter as a unit of energy is not the same as the newton meter unit of force for torque.

The energy unit meter is distance moved, while the force unit meter is the length of the moment arm.

This is confusing even though valid, so the energy unit version is rarely used.

You can exert newton meters of force while using no energy, say by standing on a lug nut wrench allowing gravity to exert the force indefinitely unless the nut breaks loose.

Re: CO2 batteries that store grid energy take off globally

#143

Post by svpk »

Waterluvian wrote: post #117
nayuki wrote: post #109

> The tried-and-true grid-scale storage option—pumped hydro [--> https://spectrum.ieee.org/a-big-hydro-project-in-big-sky-cou... ], in which water is pumped between reservoirs at different elevations—lasts for decades and can store thousands of megawatts for days. > Media reports show renderings of domes but give widely varying storage capacities [--> https://www.bloominglobal.com/media/detail/worlds-largest-co... ]—…

If 1 watt is 1 joule per second then, honestly, what are we doing with watt-hours? Why can’t battery capacity be described in joules? And then charge and discharge being a function of voltage and current, could be represented in joules per unit time. Instead its watt-hours for capacity, watts for flow rate. Watt-hours… that’s joules / seconds * hours? This is cursed.

I believe it's just a matter of intuitively useful units. There's simply too many seconds in a day for people to have an immediate grasp on the quantity. If you're using a space heater or thinking about how much power your fridge uses kilowatt hours is an easy unit to intuit. If you know you have a battery backup with 5 kilowatt hours of capacity and your fridge averages 500 watts then you've got 10 hours. If you convert it all to watt seconds the mental math is harder. And realistically in day to day life most of what we're measuring for sake of our power bill, etc. is stuff that's operating on a timetable of hours or days.

Re: CO2 batteries that store grid energy take off globally

#144

Post by ted_dunning »

hkt wrote: post #130
B1FF_PSUVM wrote: post #115

Earlier quoted context omitted.

> big yikes for something coming out of the Institute of Electrical and Electronics Engineers. Besides the unit flub, there's an unpleasant smell of sales flyer to the whole piece. Hard data spread all over, but couldn't find efficiency figures. Casual smears such as "even the best new grid-scale storage systems on the market—mainly lithium-ion batteries—provide only about 4 to 8 hours of storage" (huh, what, why?).…

I'm sat here thinking: why not compressed or liquefied air?

The basic issue is that they need a phase change at a reasonable temperature. Liquifying air requires much lower temperatures than CO2.

Re: CO2 batteries that store grid energy take off globally

#145

Post by nanomonkey »

pjc50 wrote: post #107
nanomonkey wrote: post #70

I'm curious if this method could be used along with super critical CO2 turbine generators. In other words after extracting the energy stored in compressed CO2, if you could then run it through a heat exchanger to bring it up to super critical temps and pressure and then utilize it as the working fluid in a turbine.

It looks from the diagram that a turbine is the energy extraction mechanism? As you'd expect.

Correct, going from cold compressed liquid co2 though. For supercritical CO2 one would then heat up the gas and use it as a working fluid to turn the turbines further.

If you could reuse the same turbine, one could store excess solar/wind energy in the compressed gas form, and then fire up a natural gas or biomass gasification reactor and then feed the heat into the system to produce more electricity on demand.

Re: CO2 batteries that store grid energy take off globally

#146

Post by anjel »

crystal_revenge wrote: post #114
lambdaone wrote: post #8

This seems almost too good to be true, and the equipment is so simple that it would seem that this is a panacea. Where are the gotchas with this technology? Clearly power capacity cost (scaling compressors/expanders and related kit) and energy storage cost (scaling gasbags and storage vessels) are decoupled from one another in this design; are there any numbers publicly available for either?

If you think this is simple, wait until you learn about oceans and forests do! Trees are literally CO2 based solar batteries: they take CO2 + solar energy and store it as hydrocarbons and carbohydrates for later use. Every time you're sitting by a campfire you're feeling heat from solar energy. How much better does it get that free energy storage combined with CO2 scrubbing from the atmosphere! When you look at the o…

Not nearly just Brazil: https://awpaadelaide.com/2025/08/10/who-is-clearing-indonesi...

Re: CO2 batteries that store grid energy take off globally

#147

Post by ycui1986 »

3eb7988a1663 wrote: post #42
lambdaone wrote: post #35

Earlier quoted context omitted.

I see this as complementary to other energy storage systems, including sodium ion batteries; each will have its own strengths and weaknesses. I expect energy storage density cost will be the critical parameter here, as this looks best suited to do diurnal storage for solar power systems near out-of-town predictable power consumers like data centers.

Maintenance of the system is my biggest question. Lot of mechanical complexity with ensuring your gas containment, compressors, turbines, etc are all up to spec. This also seems like a system where you want to install the biggest capacity containment you can afford at the onset. All of that vs lithium/sodium where you can incrementally install batteries and let it operate without much concern. Maybe some heaters if t…

from the picture, the compressor and generator located inside the dome. the dome is filled with CO2. maintenance people have to carry oxygen tank, or they die.

Re: CO2 batteries that store grid energy take off globally

#148

Post by andrewflnr »

belviewreview wrote: post #113

I seem to recall from an article I read about this technology a few years ago that it's efficient partly because when the gas is compressed, they are able to store the heat that is produced, and then later use the stored heat for expanding the gas.

That seems important. I wish we knew how. I found an article that did mention the heat was "stored", with no further detail. The animation down on this page suggests it's stored in water somehow: https://energydome.com/co2-battery/

Re: CO2 batteries that store grid energy take off globally

#149

Post by fragmede »

B1FF_PSUVM wrote: post #115
nayuki wrote: post #109

> The tried-and-true grid-scale storage option—pumped hydro [--> https://spectrum.ieee.org/a-big-hydro-project-in-big-sky-cou... ], in which water is pumped between reservoirs at different elevations—lasts for decades and can store thousands of megawatts for days. > Media reports show renderings of domes but give widely varying storage capacities [--> https://www.bloominglobal.com/media/detail/worlds-largest-co... ]—…

> big yikes for something coming out of the Institute of Electrical and Electronics Engineers. Besides the unit flub, there's an unpleasant smell of sales flyer to the whole piece. Hard data spread all over, but couldn't find efficiency figures. Casual smears such as "even the best new grid-scale storage systems on the market—mainly lithium-ion batteries—provide only about 4 to 8 hours of storage" (huh, what, why?).…

> only about 4 to 8 hours of storage" (huh, what, why?)

Or it's just so obvious - to them! that it doesn't need to be mentioned, which then doesn't make it an ad.

Lithium ion battery systems are expensive as shit, and not that big for how much they cost.

Re: CO2 batteries that store grid energy take off globally

#150

Post by cornstalks »

mannyv wrote: post #137

I have two solar panels that can generate around 960w/hr. Both panels cost around $400 ($200x2). Cheap. Storing that energy is quite expensive. an Anker Solix 3800, which is around 3.8kwh, costs $2400 USD. To store 10kwh would cost $7200 USD (which gets us more than 10kwh). If that cost asymmetry can come down then it becomes feasible to use solar power to provide cheap/local electricity in poor countries at a house…

There are way cheaper options than the Anker Solix 3800. Here are some options, in no particular order:

- $3,300: 10 kWh with 2x EG4 WallMount Indoor 100Ah.

- $3,110: 14 kWh with 1x WallMount Indoor 280Ah.

- $2,690: 10 kWh with 1x Deye RW F10.2 B

- Will Prowse's YouTube channel has reviewed several battery builds that are >10 kWh and near $2,000, but they're DIY assembly.

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