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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

#11

Post by scotty79 »

"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 the battery, the process reverses. The liquid CO2 is evaporated and heated. It then enters a gas-expander turbine, which is like a medium-pressure steam turbine. This drives a synchronous generator, which converts mechanical energy into electrical energy for the grid. After that, the gas is exhausted at ambient pressure back into the dome, filling it up to await the next charging phase."

Re: CO2 batteries that store grid energy take off globally

#12

Post by zahlman »

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?

Well, it isn't going to sink enough CO2 to move the needle:

> If the worst happens and the dome is punctured, 2,000 tonnes of CO2 will enter the atmosphere. That’s equivalent to the emissions of about 15 round-trip flights between New York and London on a Boeing 777. “It’s negligible compared to the emissions of a coal plant,” Spadacini says. People will also need to stay back 70 meters or more until the air clears, he says.

So it's really just about enabling solar etc.

Re: CO2 batteries that store grid energy take off globally

#13

Post by scotty79 »

AndrewDucker wrote: post #2

No 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.

Also sodium batteries are coming to the market at a fraction of the cost.

"We’re matching the performance of [lithium iron phosphate batteries] at roughly 30% lower total cost of ownership for the system." Mukesh Chatter, cofounder and CEO, Alsym Energy

Re: CO2 batteries that store grid energy take off globally

#14

Post by _aavaa_ »

Gys wrote: post #9
AndrewDucker wrote: post #2

No 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.

Lithium supply is limited. So an alternative based on abundant materials is interesting for that reason I guess?

Lithium is not that limited, current reserves are based on current exploration. More sources will be found and exploited as demand grows.

And if you want an alternative, sodium batteries are already coming online.

Re: CO2 batteries that store grid energy take off globally

#15

Post by Tade0 »

Gys wrote: post #9
AndrewDucker wrote: post #2

No 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.

Lithium supply is limited. So an alternative based on abundant materials is interesting for that reason I guess?

There are over 200 billion tonnes of lithium in seawater, it's just the least economical out of all sources of this element.

There are plenty more, but they're explored only when there's a price hike.

Re: CO2 batteries that store grid energy take off globally

#16

Post by standeven »

_aavaa_ wrote: post #14
Gys wrote: post #9

Earlier quoted context omitted.

Lithium supply is limited. So an alternative based on abundant materials is interesting for that reason I guess?

Lithium is not that limited, current reserves are based on current exploration. More sources will be found and exploited as demand grows. And if you want an alternative, sodium batteries are already coming online.

It's also very recyclable, so big batteries that reach end of life can contribute back to the lithium supply.

Re: CO2 batteries that store grid energy take off globally

#17

Post by ajb »

readthenotes1 wrote: post #3

Does 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.

Re: CO2 batteries that store grid energy take off globally

#19

Post by standardUser »

I've been waiting for large-scale molten salt/rock batteries to take off. They've existed at utility scale for years but are still niche. They're not especially responsive and I imagine a facility to handle a mass amount of molten salt is not the easiest/cheapest thing to build.

This sounds better in every way.

Re: CO2 batteries that store grid energy take off globally

#20

Post by Herring »

AndrewDucker wrote: post #2

No 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.

Efficiency isn't that important if the input cost is low enough. Basically the utility is throwing it away (curtailment) so you probably can too. CAPEX is really the most important part of this.
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