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I think this is the paper behind that.[1] Round trip efficiency is listed there as about 75%.
It was previously proposed at Lawerence Livermore.[2] It was apparently tried in China in 2016, at least at pilot plant stage.
It's an obvious idea. There's been lots of interest in compressed air storage, and compressed CO2 storage is in some ways easier, because you can liquify it easily. So why hasn't this come up much before?
[1] https://sco2.eu/fileadmin/user_upload/presentations/2021/Man...
[2] https://www.forbes.com/sites/jeffmcmahon/2017/03/26/how-capt...
>So why hasn't this come up much before?
My guess is volumetric inneficiency. This will be an alternative to pumped hydro, not batteries. But this has none of the conveniences of pumped hydro - nature already built the holding tank and you only need a pump and generator.
Storing all the uncompressed CO2 will require a massive structure for relatively little energy storage.
The other large aspect is that the technology has the same major issue as pumped hydro when compared to lithium-ion batteries. They don't give a clear return of investment.
Long duration general means that the intended target has a long charge cycle, and the longer the charge cycle is, the longer it will take to get an return of the investment. In contrast, lithium-ion batteries (with solar) is used with a daily charge cycle which means that calculating a return of investment is almost trivial. Every day the sun go down, demands goes up, batteries are discharged. Long duration storage tend to be combined with wind, and so you discharge during days of calm weather.
>But this has none of the conveniences of pumped hydro - nature already built the holding tank and you only need a pump and generator.
Only if you're in an area with favourable geography, of course...
I'm surprised nobody has posted the "revolutionary battery checklist" meme comment yet. It's exciting to see all these developments in clean-tech but the headlines always seem to mischaracterize the actual stage of development these technologies seem to be in.
Even if the battery has 100% efficiency, the amount of electric energy one would need to store for a single day, on top of the normal power consumption, is just way too much.
Nuclear reactions have the highest energy density of any of the technology available to mankind.
Thus, with evergrowing energy needs, nuclear power will always remain the only scalable, carbon-free technology.
Ironically, the introduction of battery storage makes nuclear more price competitive with coal and gas since it can run at a steady state and the battery can smooth out the demand fluctuations. This is why a lot of pumped hydro is built in conjunction with nuclear.
But since solar and wind get cheaper from the same effect, it doesn't really help nuclear much.
The failure to properly use nuclear power might be the single saddest thing about modern technology use by humanity.
In a 100 years you will look back and write Hacker News comments and say 'but they had the technology in the 60s, why were they not using it. It makes no sense'.
Nuclear is great for steady, base-loads, but it doesn't do variability well. Demand is highly variable throughout the day.
Batteries, like this system, convert steady base load into variable output by storing energy. Fill up at night, then output when needed during the day.
Batteries make nuclear energy more viable.
So you'd support the construction of twenty new reactors in Iran to help them meet their energy needs without burning so much oil?
What is the "revolutionary battery checklist" meme comment?
This one I presume:
----------------------------------------------------------------
Dear battery technology claimant,
Thank you for your submission of proposed new revolutionary battery technology. Your new technology claims to be superior to existing lithium-ion technology and is just around the corner from taking over the world. Unfortunately your technology will likely fail, because:
[ ] it is impractical to manufacture at scale.
[ ] it will be too expensive for users.
[ ] it suffers from too few recharge cycles.
[ ] it is incapable of delivering current at sufficient levels.
[ ] it lacks thermal stability at low or high temperatures.
[ ] it lacks the energy density to make it sufficiently portable.
[ ] it has too short of a lifetime.
[ ] its charge rate is too slow.
[ ] its materials are too toxic.
[ ] it is too likely to catch fire or explode.
[ ] it is too minimal of a step forward for anybody to care.
[ ] this was already done 20 years ago and didn't work then.
[ ] by this time it ships li-ion advances will match it.
[ ] your claims are lies.
----------------------------------------------------------------
And how much we miss on really interesting other concepts, because focusing on the wrong thing? It would be great to know.
The problem with this is not storing the liquid CO2, it's storing the "spent" low pressure CO2 gas. The volume required will be very large. The energy/volume of this will be even worse than pumped hydro.
Interesting: CO2 gets pressurized, cooled to liquid temperatures via refrigeration, then uncompressed to spin a turbine when energy is needed.
Concerning:
> The engineer explains that Energy Dome does not want to build projects itself.
> “We don’t have the capability to grow as fast as the market requires,” he says. “So our model is to license the technology to EPC companies or IPPs, utilities, the final user, because that is the best way for us to expand geographically and by sector.
They are so confident in the economics of this tech that they'd rather someone else invest in it. How generous and not at all suspicious.
> They are so confident in the economics of this tech that they'd rather someone else invest in it. How generous and not at all suspicious.
This is not an entirely uncommon business model, and there are numerous examples of the developers of a technology licensing it for production and distribution. ARM is itself one example of this.
https://en.wikipedia.org/wiki/Arm_Ltd.#Business_model
It is entirely valid for a technology inventor to commercialize their invention by partnering with a manufacturer that already has the necessary production capacity, rather than by raising outside money to scale up their company and build new production capacity. The former can often be a lower-risk, higher-reward approach compared to the latter.
The real question is whether the technology actually works. If they can prove it works, the fact that they would license this technology to third parties for manufacturing and distribution is not itself suspicious at all.
> They are so confident in the economics of this tech that they'd rather someone else invest in it. How generous and not at all suspicious.
I mean, I think this is pretty standard in highly capital intensive industries?
This is common in the electric utility industry where scaled up tech costs 7-9 figures per unit or more.
> Interesting: CO2 gets pressurized, cooled to liquid temperatures via refrigeration, then uncompressed to spin a turbine when energy is needed.
Can someone explain the maximum theoretical efficiency of this process from basic thermodynamic principles?
Carnot cycle, isn't it? Not great for efficiency, probably less than 50% round trip.
Basic thermodynamics doesn't prevent you from cooling something reversibly.
That said plenty of the steps involved here are likely not 100% efficient, and I'm somewhat unsure where they're recovering the energy involved in the gas-liquid phase-transition, if at all.
The whole article is leaning a little bit too much on the "what if"-part of things. First it will be important to see whether their first at-scale Prototype actually works next year.
Honestly I don't see why it wouldn't work. All the steps of the process seem like old and proven technology to me. Perhaps the only innovation is this "elastic" CO2 storage for ambient temperature/pressure ?
However, the key information will be performance numbers actually coming out of it
> cooled to liquid temperatures via refrigeration
Do you actually need to refrigerate it to keep it liquid? My SodaStream machine works with room temperature.
My understanding is that the energy released comes from the CO2 being heated back up and turning into a gas, causing it to expand. This spins turbines.
"It can only exist at a pressure above 5.1 atm (5.2 bar; 75 psi), under 31.1 °C (88.0 °F)" - https://en.wikipedia.org/wiki/Liquid_carbon_dioxide
So depending where you are you'd need refrigeration
Sodastream doesn’t use liquid CO2, just compressed gas.
There's nothing usual about that. Lots of technologies get licensed.
Is it defensible (patents etc)? If it's easy to copy then it would be best to partner with those who need to invest the least to get this to market.
imagine a world where your inexperienced take gets amplified unceremoniously
and here we are
Such confidence. Will make…. Unprecedented….
5bere would be so many ideas that have not scaled, run into technical problems, ……. Would be nice if they had data from a pilot plant that was representative
How efficient is the system? Liquifying is nowt without losses and neither is turning pressure into electricity.
Edit: They claim 75-80%. Is that realistic?
Edit: Does this include the assumption that the compression heat can be used? „The heat is then extracted and stored in “bricks” made of steel shot and quartzite for later use, cooling down the CO2 to an ambient temperature.“
> Edit: They claim 75-80%. Is that realistic?
Seems very doubtful, based on the reported temperature differential and the formula for the theoretical maximum efficiency of a Carnot cycle heat engine.
I wish there were more articles that went along the lines of, this is a revolutionary new technology that has been in use for a few years and is gaining steam rather than this is a revolutionary new technology set to change the world sometime in the future (such as this article)
I think we can "thank" the popularity of the startup business model (and the prolific idea/delusion that this is where innovation takes place) first and foremost for that.
Personally, I've rather just seen an increase in deception and questionable investments (of money and other resources), compared to more traditional approaches. I'd even go as far as to call most of the startup based industry "Smoke and Mirrors Inc", but that might be a bit on the cynical side.
Still, securing more investments for "potential" solutions (more like regardless of actual feasibility) appears to have become a higher priority than actually showing/proving that something is an improvement (by any measure besides the financials gains for early investors).
EDIT: While this sure does not rule out the possibility of true innovation and progress, I can't say I'm impressed with the actually success ratio. Combined with the amount of downright deception I've seen, usually without legal consequences (let alone penal ones), I wonder if the net sum is even a move in the positive direction.
Somebody in that company is a fan of Devo...
Anyone know why you would need to store CO2 and not just regular air in this case?
In the article:
"Spadacini explains that Energy Dome uses CO2 because it can be converted into liquid under pressure at 30°C, compared to minus 150°C for air. Highview Power’s liquid-air battery therefore has to use cryogenic technology to liquefy air, but the Energy Dome system requires far less power, resulting in cheaper costs and a higher round-trip efficiency, the company says."
Fair’s fair, I have to ask what happens when one of these fails catastrophically? The step where the CO2 reaches 300C while surrounded by “steel shot” bricks sounds like it could be the world’s biggest pipe bomb. Although even a large leak could kill nearby people and wildlife through suffocation.
CO2 is lighter than air and it doesn’t oxidize much. Seems like a safer option to many other alternatives.
unless they are getting their CO2 from capturing it out of the atmopsphere, I see this as a way to dirty up wind and solor even more than they already are from their manufacturing.
> When electricity is required, the liquid CO2 is run through an evaporator to turn it back to a pressurised gas, which is then warmed up back to 290-300°C causing the stored heat. The gas is then introduced into an expansion turbine, where it rapidly expands at atmospheric pressure to drive a power-generating rotor, with the uncompressed CO2 then stored in a flexible dome — hence the company name — at ambient temperature and pressure for later re-use.
It's a closed loop system, so it doesn't seem particularly dirty to me, presuming the energy to run it will come from the renewable source that it's storing. The materials used to make it (steel, quartzite, PVC) don't seem too troubling.
Seems a bit cleaner than chemical batteries at first glance.
I imagine it's a closed system, so the question of where the CO2 comes from is kind of irrelevant.
I think we need an energy revolution. We still try to do this a way where there is a turbine in the process. Motionless energy storage is much more promising.
That article says that fuel cells are 40-60% efficient. This process is claimed to be 80% efficient.
80% round trip efficiency is killer for what they are selling here though. That 20% loss is directly cutting into your trading margin. imagine you buy 1MWh at 100USD; you immediately lose 20% of it, so you now need prices at $125 just to break even.
The ability of higher efficiency technologies to perform many more profitable trades in a given year has a significant impact on ROI.
Due to Solar, some hours of the day have negative energy prices. Your profit potential is infinite if you can charge from 11am - 5pm and then release it all from 7pm-midnight.
https://www.researchgate.net/publication/341393321/figure/fi...
What we should be doing though is building this smart charging and dispatch functionality into cars, so that we don't make our existing electricity peaks even peakier when people get home from work and immediately plug in and charge their EVs.
Ideally people would charge their cars at work, during the day. I guess we need to lean on employers with huge parking lots to provide EV charging.
Don't spot prices for energy fluctuate wildly especially now with renewables in the mix?
What does it matter you lose 20% if the alternative is selling at a loss?