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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

#271

Post by nine_k »

ycui1986 wrote: post #139
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 think it had something to do with CO2 can be made into supercritical state relatively easily, not for nitrogen or other common gases.

You can do it easily with something like propane, or other larger molecules. But CO2 is non-flammable, largely non-toxic, and easily available.

Re: CO2 batteries that store grid energy take off globally

#272

Post by abdullahkhalids »

pfdietz wrote: post #88
perlgeek wrote: post #87

Earlier quoted context omitted.

We need every approach that's viable. Batteries are part of the solution, and will be in future. But I don't see why we we should assume they're better in every way than this approach

A principle in engineering is that for any market niche, only a few, or even one, technology persists. The others are driven to extinction as they can't compete. It's the equivalent of ecology's "one niche, one species" principle. There are far more technologies going for the hours scale storage market than will survive. Sure, explore them. But expect most to fail to compete.

This is not true for batteries at all. Just take a look at [1]. Many of these battery chemistries are in wide use. Batteries have several performance metrics: total storage, peak/avg power, round-trip efficiency, lifetime, capex, opex,etc. The relative value of these metrics is different for different applications, so we end up with many different types of batteries being used.

Grid level batteries have another very important metric. The actual possibility of buying a particular types of batteries from friendly nations. Simpler technologies like this CO2 battery have a huge advantage here.

[1] https://en.wikipedia.org/wiki/List_of_battery_types

Re: CO2 batteries that store grid energy take off globally

#273

Post by nayuki »

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... ]—…

I should have explained in my original comment why I think those sentences are wrong. I'll do so now.

> pumped hydro [...] can store thousands of megawatts for days.

You can't "store" a megawatt – because you can only store energy, not power.

But another interpretation is, if you actually store thousands of megawatts (i.e. gigawatts) for days, then at the very least, 1 GW × 1 day = 24 GW⋅h. If we take "a few" to mean 3, then 3 GW × 3 day = 216 GW⋅h. I'm not sure there exists a large enough pumped hydro plant in the world that stores 216 GW⋅h of energy. So I think the article meant to say, "store a few gigawatt-hours to be released over a period of a few days".

> Media reports show renderings of domes but give widely varying storage capacities—including 100 MW and 1,000 MW.

Once again, you can't store megawatts of power, full stop. You can store megawatt-hours of energy. The linked article at Bloomberg said that a project in China is building 600 MW of wind power, 400 MW of solar power, and 1 GW⋅h of energy storage – which is the correct unit.

Re: CO2 batteries that store grid energy take off globally

#274

Post by ses1984 »

charlieo88 wrote: post #258
tor825gl wrote: post #215

Earlier quoted context omitted.

There are two types of jobs, the ones which require you to know that a day is about 8.5x10^5 seconds, and those which don't.

Is this sarcasm?

I'm not sure if I would call it sarcasm, but it's a reference to a popular computer science joke format.

The first time I saw it:

>There are 10 kinds of people in the world, those who understand binary and those who don't.

The joke is that 10 is how you express 2 in base 2.

I think there is another layer to the joke, though; often in mathematics, computer science, algorithms, and software engineering, things get divided into sets, sets get broken down into two sets according to whether some property about the elements is true or false, and this joke echoes that.

It's just meant to be silly.

Re: CO2 batteries that store grid energy take off globally

#275

Post by nayuki »

tor825gl wrote: post #215
svpk wrote: post #143

Earlier quoted context omitted.

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 con…

There are two types of jobs, the ones which require you to know that a day is about 8.5x10^5 seconds, and those which don't.

I use the conversion factor so often that I know it by heart: 1 day = 86400 seconds. I punch that 5-digit integer into a calculator, not an approximation like 8.5e5 (which is the same length, haha).

Re: CO2 batteries that store grid energy take off globally

#276

Post by PunchyHamster »

usrusr wrote: post #224
PunchyHamster wrote: post #199

Earlier quoted context omitted.

lithium yearly discharge is in single digit %, what a nonsense argument.

GP wasn't talking about discharge, losing a little energy, they were talking about wear and tear, as in the batteries aging fast while in a highly charged state. Battery recycling still hasn't really left the "we can do it in a lab" stage.

It's more coz digging new lithium is still cheaper.

Re: CO2 batteries that store grid energy take off globally

#277

Post by to11mtm »

pfdietz wrote: post #78
api wrote: post #39

Earlier quoted context omitted.

So… it’s a compressed air battery but with a better working fluid than air. I remember wondering about using natural gas or propane for this a long time ago. Not burning the gas but using it as a compressed gas battery. It liquifies easier than air, etc., but would be a big fire risk if there were leaks while this is not. Seems neat.

Except you have to trap and recycle the uncompressed CO2, hence that enormous bag to hold all that gas. Color me skeptical. With compressed air, you just release the air back to the atmosphere.

> With compressed air, you just release the air back to the atmosphere.

The issue with compressed air is that you have to build more of the system to handle higher pressures and/or have a more robust regulator design, plus the pressures required to compress CO2 back to liquid are typically lower than what you'd need to store a useful final volume compressed air...

Also, As far as having an 'open loop' (i.e. venting to atmosphere), that's typically got it's own problems, mostly that when you need new air you have to make sure it's 'pure', not just things like dust but even whether there's water vapor.

Re: CO2 batteries that store grid energy take off globally

#278

Post by PunchyHamster »

audunw wrote: post #218
PunchyHamster wrote: post #192

Earlier quoted context omitted.

If it is barely cheaper than lithium, it's much more expensive than traditional pumped storage. Yeah, it's expensive to build, but then cheap to run for decades. It's nice that we explore alternatives but this just seems like investor bait

Pumped hydro is just not a valid comparison. I wish people would understand that already… it’s only good for long term storage in certain key geographical regions. Its use case is very limited. You don’t want to used pumped hydro for short term storage because the rapid cycling will drive up the maintenance costs. You actually hear about hydro power plants talking about installing batteries to reduce wear. In these d…

It's cute you think short cycles are somehow better in gas turbines and compressors and that you will restart the whole thing constantly to fill short term demands

> In these discussions please keep in mind that frequency regulation, short term and long term shortage are different applications with different needs.

The comparison is valid; If you want to fill hour to hour demand or add some frequency regulation, an inverter with a bunch of batteries is far, far better than this

> You don’t want to used pumped hydro for short term storage because the rapid cycling will drive up the maintenance costs. You actually hear about hydro power plants talking about installing batteries to reduce wear.

They are still cycled daily, that's the entire point of them that even worked pre renewables - load up on cheap night energy and unload it with demand. Renewables just flipped that to load in solar peak.

And putting few hours worth of batteries to reduce cycling is beneficial in both of those cases.

Re: CO2 batteries that store grid energy take off globally

#279

Post by GuB-42 »

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.

1 Wh = 3600 Ws = 3600 J

It is not more cursed than km/h (1 m/s = 3600 m/h = 3.6 km/h)

Both those units are more convenient than their SI equivalent and their "cursedness" come from the hour/minute/second time division.

If we had decimal time, as it was initially proposed with the metric system, we wouldn't have this problem, but we weren't ready to let go of hours/minute/second.

Re: CO2 batteries that store grid energy take off globally

#280

Post by pfdietz »

abdullahkhalids wrote: post #272
pfdietz wrote: post #88

Earlier quoted context omitted.

A principle in engineering is that for any market niche, only a few, or even one, technology persists. The others are driven to extinction as they can't compete. It's the equivalent of ecology's "one niche, one species" principle. There are far more technologies going for the hours scale storage market than will survive. Sure, explore them. But expect most to fail to compete.

This is not true for batteries at all. Just take a look at [1]. Many of these battery chemistries are in wide use. Batteries have several performance metrics: total storage, peak/avg power, round-trip efficiency, lifetime, capex, opex,etc. The relative value of these metrics is different for different applications, so we end up with many different types of batteries being used. Grid level batteries have another very…

Of course it's true for batteries. There's a huge number of potential battery types, most of which never make it out of the lab, never mind to market. Most on your list there are in are in tiny niches.

To steelman the point you're making: perhaps the short term storage niche will fracture into smaller niches, in which different technologies could coexist. This also happens in ecology. For example, in one simple experiment with bacteria, it was found two species coexisted, but on closer examination it was found one species persisted in the top of the flasks, the other in the bottom.

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