Is the CO2 battery for long-duration energy storage any good?

Posted: November 23, 2022 by oldbrew in Batteries, climate, Energy, innovation
Tags: , , ,

The makers say: ‘To charge the battery, we take CO2 at near atmospheric temperature and pressure and we compress it. The heat that is generated during compression is stored. When we exchange the thermal energy with the atmosphere, the CO2 gas becomes liquid.

To generate and dispatch electricity, the liquid CO2 is heated up and converted back into a gas that powers a turbine, which generates power. The CO2 gas is always contained and the entire system is sealed. We don’t use any exotic materials.’
— Looks like another net user of power.

– – –
Italian startup Energy Dome, maker of the world’s first CO2 battery, is officially entering the US market, says Electrek.

Energy Dome’s battery uses carbon dioxide to store energy from wind and solar on the grid.

World’s first CO2 battery

Energy Dome announced earlier this month that it has been awarded funding and networking support from Hawaii and Bay Area-based Elemental Excelerator, which invests in climate tech deployment.

Elemental said it was funding Energy Dome because “the ability to store energy from intermittent sources like solar and wind for prolonged periods has long been a missing piece of the decarbonization puzzle.”

When Electrek asked Energy Dome about its US market-entry plan, a spokesperson replied:

The US market is a primary market for Energy Dome and we are working to become a market leader in the US. The huge demand of [long duration energy storage] and incentive mechanisms like the Inflation Reduction Act will be key drivers for the industry in the short term.

Energy Dome has all the key features to deploy the most needed LDES solutions. Our process is based on existing off-the-shelf components known to the US energy industry.

Energy Dome is ready to deploy commercial-scale projects throughout the US, and we are nurturing a strong pipeline in the country, which should translate into a first commercial deployment already in 2024. Our technology uses an accessible supply chain and allows our customers to access extended investment tax credits.

Energy Dome began its operations in February 2020 and has progressed from a concept to full testing at multi-megawatt scale in just over two years. It sited its first CO2 battery in an industrial area with an existing electrical connection in Sardinia.

At the end of June, Energy Dome announced that it secured $11 million in bridge funding that it used to buy equipment for a 20-megawatt/200-megawatt-hour/10-hour duration facility for Italian utility A2A, with which it has a memorandum of understanding.
. . .
How the battery works

CO2 is one of the few gases that can be condensed and stored as a liquid under pressure at ambient temperature, so, as Energy Dome states on its website, it’s the perfect fluid to store energy cost-effectively in a closed thermodynamic process.

It allows for high-density energy storage without the need to go to extremely low temperatures.

Full article here.

  1. tallbloke says:

    It’s less an issue of it being a net energy user than the capital cost of all the equipment. Wind turbines generate whenever the wind blows within goldilocks parameters, even if there’s no demand for the energy. So if that unused energy charges the battery, and then it’s discharged whe energy is needed but the wind isn’t blowing, then it’s a win.

    But, if $11 million buys you the kit you need for the battery, and many millions more buys you the wind turbines, and the full setup has a life of 20 years, what does the price per MWatt/hr come out at? A lot more than a gas turbine and a few fracking wells, that’s for sure.

  2. Gamecock says:

    Stop abusing our language. It’s not a %^&#ing battery.

    ‘a gas that powers a turbine’ isn’t a battery.

  3. catweazle666 says:

    “The heat that is generated during compression is stored.”. How?
    To generate and dispatch electricity, the liquid CO2 is heated up and converted back into a gas”

    Inefficient or what…

  4. cognog2 says:

    These people have not done an energy balance based on the Thermodynamic laws which they will not be able to ignore.

    It appears that they have cobbled up a financial budget which appears to produce a good return on investment; but is easily done with all the tricks of the trade now available to the financial sharks.

    I would be happy to see this go ahead and even more happy to see it go Pop; but would be very unhappy should any public money (my money) go to any bailout or redundancy fees contributions.
    It should be made quite clear to ALL involved in such a scheme that they are on their own in financial terms and I include employees, suppliers and customers in this.

    The bottom line here is that the Thermodynamic Laws CANNOT BE IGNORED AND MUST BE OBEYED.

  5. Curious George says:

    No data on a round-trip efficiency – say, we store 100MWh energy. How much can we get back?

  6. JB says:

    “high-density energy storage”
    smirk smirk smirk


  7. oldbrew says:

    There’s usually an air of desperation surrounding these types of scheme.

    Energy Storage Is The Backbone Of The Renewable Revolution
    Nov 22, 2022

    — The world is racing to ramp up renewable energy capacity.
    — Energy storage is quickly emerging as a key piece of the renewable energy puzzle.
    — The race is on to develop long-term, scalable energy storage that is environmentally friendly.
    . . .
    While there are a litany of promising options for energy storage, one of the newest developments is also one of the most exciting: the CO2 battery.

    Racing? Puzzle? Scalable? Exciting? Dream on…you’re competing with on-demand coal, gas and oil. Where’s the *backbone*?

  8. Gamecock says:

    ‘Energy storage is quickly emerging as a key piece of the renewable energy puzzle.’

    Wind/solar renewables are not viable, due to their intermittency. ‘Storage’ cannot save them. This propaganda line is to get people to believe they can be viable. It has nothing to do with CO2 compression or turbines. It is self-evident this won’t work. But that’s not it’s purpose; it is to get people to believe, to accept the destruction of their energy systems.

  9. This was written:
    CO2 is one of the few gases that can be condensed and stored as a liquid under pressure at ambient temperature, so, as Energy Dome states on its website, it’s the perfect fluid to store energy cost-effectively in a closed thermodynamic process.

    One of the few:
    Liquid Air, just pressurize and cool the air, the atmosphere, there is also liquid Oxygen, liquid Hydrogen, liquid Nitration, liquid Helium. Liquid CO2 is common in CO2 Cartridges, Dry Ice is solid CO2, You do not get as much energy back as used to compress it, not counting the fossil fuel energy expended to make the windmills or solar panels. It looks like we have been able to compress and liquify and store just about any gas we choose. Many gases have been used in closed loop cycles, many solids have been liquefied and used in closed high temperature cycles.
    The only reason CO2 could be a best gas for a closed thermodynamic process is because of the obscenely large subsidies for anything that related to greenhouse gases.

  10. oldbrew says:

    Energydome says:

    Our proprietary technology is based on a closed thermodynamic transformation. We manipulate the CO2 between its gaseous and liquid phase. Whenever energy is needed, the CO2 warms up, evaporates and expands, turning a turbine and generating electricity. No CO2 emissions into the atmosphere.

    By storing the CO2 in the liquid phase at ambient temperature, we are able to reduce the typical storage costs associated with Compressed Air Energy Storage without having to deal with cryogenic temperatures associated with Liquid Air Energy Storage.

  11. Graeme No.3 says:

    There are several U-tubes on this – Two bit Da Vinci was the first I saw.
    They are claiming a round trip efficiency of 70%, less than pumped storage. Also that the process uses readily available equipment and doesn’t use expensive lithium so cheaper than batteries.
    Storing the heat from compression isn’t loss free, so extra heat will need to be added.
    Also what is that dome made from? If it stores CO2 at atmospheric pressure what is the pressure in the dome when most of the CO2 is compressed. Secondly, as the CO2 expands through the turbine won’t it cool (reducing pressure)? Presumably the dome is very flexible or it has a large internal balloon (letting air in and out) to balance pressure.
    And Snowy 2 – the Australian pumped storage scheme grafts onto an existing hydro by one of our worse PMs** – was claimed would cost $2 billion but would make money by buying “cheap excess renewables” and selling it at $40 a MWh more. Since then the scheme wasn’t finished by the expected start-up date (2020) and has gone out to 2027 or 2029 and the total cost estimate is now over $10.5 billion. Truly an example of the old saying “An elephant is a mouse built by the government”.

    **And we’ve had some real looneys in the last 15 years (on both sides).

  12. cognog2 says:

    I recall that around 8 years old, at boarding school I invented a jet plane to Zap Hitler. It had a large balloon inside which got blown up when the plane dived to Zap Hitler and the balloon then ‘wooshed’ it up again to have a go at Goebles. It never got off the ground; but my prop and elastic bands ones did!👍

  13. ivan says:

    I see it now, they think they have invented a perpetual money machine. The problem is where does the energy to keep it running come from?

    If the energy used to run it exceeds the energy it can produce it is a scam.

    [reply] possible exception being pumped storage, not applicable here though

  14. Gamecock says:


    ‘The CO2 Battery can operate in charging mode (absorbing power from the grid) and discharging mode (returning power to the grid).’

    It has been specially designed to “absorb” power, and not drain it.

    I can’t find a direct statement, but all such schemes are based on the idea of “excess renewable energy,” with zero incremental cost. The irony being that as your economy is murdered by lack of power, there will be “excess renewable energy.”

  15. Bloke down the pub says:

    Entropy means all batteries are users of energy. The closest I’ve seen to getting something for nothing is from these guys.

  16. cognog2 says:

    Yes Ivan. That in essence is what the 2nd. Thermodynamic Law says; but they don’t seem to teach that anymore. How many people you know can tell what these Laws are?

  17. gbaikie says:

    It depends one who builds it.
    If run by idiots or government, you get something like Space Launch System [SLS]
    Whereas Elon Musk is building Starship.
    One could say Musk’s SpaceX gets govt subsidies, but govt not managing how Starship is built. Or Govt says we give money or buy something. And Musk I want to
    build something, cause I want it. And NASA will pay for some the costs.
    Or want build rocket that can land on Mars, NASA will pay money for Lunar lander- and Musk says, I land this thing, not designed to land on the Moon, land on Moon, for less than other can build a lunar lander.
    Upshot, NASA pays 40 billion and take forever to build SLS, with cost plus contracting,
    And will pay about 4 billion for Starship when actually functions as lunar lander.
    And NASA get a “mars lander” for no development costs.
    And of course govt can pay billions of dollar for something that never get off the ground.
    So, even if it could work, it depends on who does it and if govt running it, it
    has zero chance of working.

  18. dscott8186 says:

    “By storing the CO2 in the liquid phase at ambient temperature, we are able to reduce the typical storage costs associated with Compressed Air Energy Storage without having to deal with cryogenic temperatures associated with Liquid Air Energy Storage.”

    That used to be called a CO2 fire extinguisher…

    I have a better idea, run a pipe to the ocean bottom where CO2 is present in high concentration, pump it to the surface where it will flash to its gas phase and then under pressure sent through a turbine to produce electricity. Pipe the discharge CO2 gas over the ocean surface to be re-absorbed by the water.

  19. P.A.Semi says:

    While most of people think just about next weekend, some of them about next month, and governments only until next elections, but those who think they own the World for centuries think decades and centuries ahead…

    So while Texas has “huge” oil reserves, but if you divide it by daily “production”, it will last for some 30 years… What then, when American oil will run out? Saudis will have some more, but for astronomic prices, and over next decade it will be gone anyway… What then ?

    Or can you soothe me, that the oil reserves are significantly longer than 30 years ?

    The only or most significant problem with “renewables” are the batteries… Otherwise all forms of Solar energy (which Wind is also) are almost limitless – but without batteries their usability is low… The deserts are prime places for Solar collectors, where it doesn’t harm agriculture…

    Now Russians managed to make closed-cycle nuclear power-station, where burnt nuclear fuel can be used again and again, so this will be almost endless source of clean energy… How do Americans compete? Ridiculously not at all…


  20. oldbrew says:

    deserts are prime places for Solar collectors
    – – –
    Also prime places for dust, and lack of water to wash it off with. And solar panel efficiency, already low, declines further in higher temperatures.

    Solar panel efficiency is inversely proportional to the temperature of the weather. It is observed that the efficiency of a solar panel decreases by 10-25% with an increase in the temperature of the climate. The output of the voltage decreases with the increase in the temperature of a solar panel.

  21. cognog2 says:

    Yes Nuclear is the sensible option with fossil fuels reaching the parts that Nuclear can’t; thus making them last a lot longer.

    The best option is to vote for sane, independent, and qualified Engineers to run our energy requirements with POWER over politicians in such matters.

  22. catweazle666 says:

    dscott8186, instead of pumping the CO2 back to the surface pump it into the methane hydrate beds and pump the resulting methane back to the surface.

    Extract from:

    “The injection method, on the other hand, proceeds too slowly. Various research groups, therefore, are searching for ways to accelerate the exchange of carbon dioxide and methane. These attempts have led to some initial successes: The exchange of carbon dioxide and methane proceeds more rapidly when the CO2 is introduced into the reservoir as a warm supercritical fluid. In contrast to depressurization, the injection method has the advantage that some heat is released with the exchange of carbon dioxide and methane, which tends to sustain the dissociation process. This method is presently being advanced by German researchers.”

    It is curious that little attention is paid to this technology, which could be CO2 neutral.

  23. Graeme No.3 says:

    Yes. Years ago (1976 I think) a CSIRO researcher used solar panels in the desert – again relying on memory near Tennant Creek in the Northern Territory of Australia – and found just that. The claim was 1.1 kW per sq.metre radiation but he found about 25% less despite an apparent clear blue sky. When the sky looked dusty the incoming radiation was just below 0.5kW/sq.m. A layer of dust really reduces the hoped for yield.
    It was obviously a long time ago when CSIRO researchers relied on actual measurements not a computer model.

  24. oldbrew says:

    ‘Energy storage is quickly emerging as a key piece of the renewable energy puzzle.’

    Yes, the puzzle is: what makes them think it’s any good, at grid scale? Or if they don’t think that, and are just blowing smoke, they’re not fooling anyone who’s paying attention.

  25. catweazle666 says:

    “what makes them think it’s any good, at grid scale?”

    They’re both scientifically illiterate and innumerate, oh, and credulous.

  26. Jim F says:

    Pass something like the IRA and the shysters will come flocking from every direction..

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