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...

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.

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.

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.“

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)

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?

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.

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.

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

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.