[HN Gopher] CO2 battery could make wind and solar dispatchable a...
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CO2 battery could make wind and solar dispatchable at a lower price
Author : wjSgoWPm5bWAhXB
Score : 164 points
Date : 2021-08-01 09:52 UTC (13 hours ago)
(HTM) web link (www.rechargenews.com)
(TXT) w3m dump (www.rechargenews.com)
| modmans2nd wrote:
| 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.
| foota wrote:
| I imagine it's a closed system, so the question of where the
| CO2 comes from is kind of irrelevant.
| modmans2nd wrote:
| but the CO2 has to come from somewhere.
| chess_buster wrote:
| Buy enough dry ice from the gas station.
| ElKrist wrote:
| In the article:
|
| Spadacini adds: "The system is totally closed. We don't
| consume any CO2, it's just the working fluid that goes back
| and forth... for the life of the system, over 25 years. So we
| have no emissions in the atmosphere."
|
| So yes, it's a closed system
| SturgeonsLaw wrote:
| > 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 290-300degC 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.
| modmans2nd wrote:
| It's closed loop but where is it getting the CO2 from for the
| system?
| trenchgun wrote:
| It does not matter.
| Animats wrote:
| 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...
| dahfizz wrote:
| >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.
| Nabati wrote:
| Anyone know why you would need to store CO2 and not just regular
| air in this case?
| ElKrist wrote:
| In the article:
|
| "Spadacini explains that Energy Dome uses CO2 because it can be
| converted into liquid under pressure at 30degC, compared to
| minus 150degC 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."
| heisenbit wrote:
| 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."
| Turing_Machine wrote:
| > 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.
| namibj wrote:
| Carnot cancels out if you follow up with it in reverse.
| Turing_Machine wrote:
| Nope.
|
| While Carnot-cycle engines are reversible, the losses don't
| cancel out. You just lose the energy to entropy on both
| ends.
| jakewins wrote:
| 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.
| NonContro wrote:
| 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.
| smolder wrote:
| The profit potential is not infinite because the arbitrage
| affects the prices. If you do enough storage and release,
| eventually the load is practically flat on the generation
| side and the price fluctuations become insignificant.
| [deleted]
| the-dude wrote:
| 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?
| ElKrist wrote:
| Yes they fluctuate enough that you can make a profit even
| with a "20% loss". Here [1] you can see today's prices on the
| electricity spot market for Europe (Changing the date does
| not work in my browser though)
|
| Another way to say this is that there is a real economical
| value for storage because of the increase in renewables
|
| [1] https://www.rte-france.com/eco2mix/les-donnees-de-marche
| jakewins wrote:
| I mean, I suppose the purpose of these batteries are about
| seasonal rather than hourly differences.. but assuming you
| want to use them for something like coupling to a PV array
| and doing hourly trading:
|
| The alternative isn't selling at a loss, it's using
| technology with higher round trip efficiency.
|
| Say you have two batteries, both 1MW/4H systems, one lithium
| at 95% efficiency, one this CO2 thing at 80% effiency. In the
| highly volatile SE4 spot region in the Scandinavian grid, if
| you traded in 2019 you'd have made $80K USD with the CO2
| battery, $155K USD with the Lithium one (assuming you traded
| perfectly).
|
| A tigher efficiency envelope lets you exploit many smaller
| 10-20% cost gaps, rather than having to sit for many days to
| wait for gaps in the 30-40% range.
|
| Not to say that Lithium would have a higher ROI over all than
| this technology, just to say that round trip efficiencies
| have significant impact on revenues here.
| flavius29663 wrote:
| Here is where you're wrong: you're thinking in terms of 4
| to 1 power to storage. A CO2 battery can have a very large
| storage for 1MW. It could potentially have a storage of 40
| hours. You keep charging it for months, and then release it
| all when there is a week long lull of wind and solar
| production.
|
| Such short bursts of energy are typical for Li-Ion
| batteries, but quite atypical for other forms of energy.
| It's the same principle as with the flow batteries.
| ec109685 wrote:
| Isn't the ROI all that matters since the cost to build the
| thing is it's own efficiency loss, paid out over the
| lifetime of the project?
| jhgb wrote:
| It gets even better if you have your own generator.
| Electricity you can't sell immediately has zero value without
| storage, and you'll have increasing amounts of such
| electricity in the future.
| mabbo wrote:
| 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.
| vmception wrote:
| imagine a world where your inexperienced take gets amplified
| unceremoniously
|
| and here we are
| legutierr wrote:
| > 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.
| [deleted]
| schainks wrote:
| This is common in the electric utility industry where scaled up
| tech costs 7-9 figures per unit or more.
| rsynnott wrote:
| > 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?
| amelius wrote:
| > 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?
| contravariant wrote:
| 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.
| pjc50 wrote:
| Carnot cycle, isn't it? Not great for efficiency, probably
| less than 50% round trip.
| ghkbrew wrote:
| Carnot is for heat engines. So the maximum efficiency of
| converting a heat differential into kinetic energy.
|
| This is converting electricity into kinetic energy and vice
| versa. So it'd be the product of those two maximum
| efficiencies, whatever they are.
| stjohnswarts wrote:
| There's nothing usual about that. Lots of technologies get
| licensed.
| gflarity wrote:
| 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.
| chki wrote:
| 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.
| ElKrist wrote:
| 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
| mbruce wrote:
| 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
| jannes wrote:
| > cooled to liquid temperatures via refrigeration
|
| Do you actually need to refrigerate it to keep it liquid? My
| SodaStream machine works with room temperature.
| beervirus wrote:
| Sodastream doesn't use liquid CO2, just compressed gas.
| xaduha wrote:
| Demonstrably not true. In fact you can refill your
| Sodastream canister with dry ice, google it. 400 grams of
| it sure as heck doesn't stay solid and I'm pretty sure it
| can't be gas at that pressure in that amount of space.
|
| EDIT:
| https://en.wikipedia.org/wiki/Supercritical_carbon_dioxide,
| you can't slosh it.
|
| https://www.youtube.com/watch?v=GEr3NxsPTOA
| beervirus wrote:
| It looks like you're right. Whoops.
| lbotos wrote:
| "It can only exist at a pressure above 5.1 atm (5.2 bar; 75
| psi), under 31.1 degC (88.0 degF)" -
| https://en.wikipedia.org/wiki/Liquid_carbon_dioxide
|
| So depending where you are you'd need refrigeration
| ClumsyPilot wrote:
| It doesnt need refrigeration for storage, CO2 is stored at
| higher pressure
|
| The refrigeration is needed because the process of
| compression produced huge amount of heat. And because of
| that, this method of storing energy is twice less efficient
| than batteries are
| magicalhippo wrote:
| Though they could store some of this heat for later when
| they want to extract the CO2 gas again, I suppose.
| surbas wrote:
| Which according to the article is what's happening. They
| store heat in steal piles, and release it back on
| expansion.
| cedilla wrote:
| Charging batteries also produces a huge amount of heat.
| In general, storing energy is never free. It's the
| tyranny of the second law of thermodynamics.
| ErikVandeWater wrote:
| Yes, the critical point for condensation of CO2 is 31 C:
|
| https://courses.lumenlearning.com/physics/chapter/13-5-ph
| ase...
|
| However, I imagine you could wait for your too-hot-to-
| condense gas to cool and condense. That would probably be
| vastly more efficient than adding refrigeration.
|
| It would depend on the materials used for the pressure
| tank, whether you can add more surface area and the
| external temperature.
|
| You could even put the CO2 Tank under water in a deep
| lake/ocean. Then you don't have to have such thick
| materials to contain the pressure. The CO2 could be
| dissipating its heat and pressurizing as you pump it down
| (use a flexible tube so the water is compressing the
| CO2). For the return journey, use a rigid pipe so it
| doesn't lose energy pushing outward on a flexible pipe.
| [deleted]
| mabbo wrote:
| 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.
| loufe wrote:
| 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.
| cbmuser wrote:
| 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.
| nickik wrote:
| 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'.
| AlexanderDhoore wrote:
| What is the "revolutionary battery checklist" meme comment?
| Escapado wrote:
| 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.
|
| -------------------------------------------------------------
| ---
| m_mueller wrote:
| article actually seems to cover all this issues well
| (except maybe for 'your claims are lies'), so I'm hopeful
| about this one.
| xxs wrote:
| >liquid-CO2 system has a round-trip efficiency of 75-80%
|
| You mean this part?
|
| Edit: this is pretty much theoretical Carno cycle and it
| has moving parts
| m_mueller wrote:
| I think even 60% efficiency would still be fine if the
| storage was cheap enough and scales well. Just build more
| solar cells or wind mills to compensate the inefficiency.
| Neither lithium-ion nor gravity based systems seem
| particularly scalable to me. So a good-enough system
| that's scalable will be a winner in the long run I think.
| jvanderbot wrote:
| That's for heat conversion, no? This isn't about heat.
| StreamBright wrote:
| And how much we miss on really interesting other concepts,
| because focusing on the wrong thing? It would be great to know.
| throwaway316943 wrote:
| 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.
| notimetorelax wrote:
| CO2 is lighter than air and it doesn't oxidize much. Seems like
| a safer option to many other alternatives.
| MattPalmer1086 wrote:
| No, it's heavier than air.
| inglor_cz wrote:
| Carbon dioxide is _heavier_ than air and concentrates e.g. on
| floors of caves, where it is deadly for smaller animals.
|
| https://www.atlasobscura.com/places/cave-of-dogs
| Eric_WVGG wrote:
| Yup. Back in 1986, Lake Nyos "belched" a cloud of carbon
| dioxide. Instead of going up, it went out, killing
| everything in its path. 1700 villagers, animals, even the
| insects. The homes (and presumably the plants) just sat
| there. https://en.m.wikipedia.org/wiki/Lake_Nyos
| joelthelion wrote:
| > CO2 is lighter than air
|
| It is not : https://en.m.wikipedia.org/wiki/Carbon_dioxide
| [deleted]
| throwaway316943 wrote:
| Don't need oxidation when you have extremely high pressure to
| get an explosive result.
| jannes wrote:
| It's actually part of "air":
|
| > By volume, dry air contains 78.08% nitrogen, 20.95% oxygen,
| 0.93% argon, 0.04% carbon dioxide, and small amounts of other
| gases
|
| https://en.wikipedia.org/wiki/Atmosphere_of_Earth
| nashashmi wrote:
| Heavier than air by measurement of molecular weight.
|
| When hot it rises up into the atmosphere. When cool it comes
| down. That is why co2 concentrates on ground in cool forests
| but floats high in urban places.
| jefurii wrote:
| Somebody in that company is a fan of Devo...
| pfdietz wrote:
| 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.
| StreamBright wrote:
| 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.
|
| https://en.wikipedia.org/wiki/Fuel_cell
| AndrewDucker wrote:
| That article says that fuel cells are 40-60% efficient. This
| process is claimed to be 80% efficient.
| legulere wrote:
| Also for this system that's the efficiency for the whole
| cycle electricity to electricity. For the fuel cell you have
| to multiply by the efficiency for creating your fuel.
| StreamBright wrote:
| Yeah the first part of that article says so.
|
| However when you continue reading: In
| addition to electricity, fuel cells produce water, heat and,
| depending on the fuel source, very small amounts of nitrogen
| dioxide and other emissions. The energy efficiency of a fuel
| cell is generally between 40 and 60%; however, if waste heat
| is captured in a cogeneration scheme, efficiencies of up to
| 85% can be obtained.[1]
|
| Based on the other details like energy density for example, I
| think this tech has a bright future. In
| electrical terms, the energy density of hydrogen is equal to
| 33.6 kWh of usable energy per kg, versus diesel which only
| holds about 12-14 kWh per kg. What this really means is that
| 1 kg of hydrogen, used in a fuel cell to power an electric
| motor, contains approximately the same energy as a gallon of
| diesel.[2]
|
| 1. https://en.wikipedia.org/wiki/Fuel_cell#cite_note-Types1-5
|
| 2. https://rmi.org/run-on-less-with-hydrogen-fuel-cells/
| jhgb wrote:
| So it's around 50%. If you consider the losses in creating
| hydrogen, the roundtrip is around 40% or so.
| InfiniteRand wrote:
| 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)
| elmo2you wrote:
| 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.
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(page generated 2021-08-01 23:02 UTC)