I honestly don't see this really taking off, batteries are too cheap already, people just haven't really realized yet.
You can just order 1kWh of storage as a prismatic LiFePO cell for about $60 and have it delivered in the same week. Battery management and inverters are a solved problem, too, and don't have moving parts either.
The mechanical complexity is what worries me most - CO2 phase changes, compression/decompression cycles, heat exchangers...that's a lot of potential failure points compared to solid-state lithium cells. When researching portable power stations (I used gearscouts to compare $/Wh across different capacities), even budget lithium units are getting surprisingly cost-effective. We're seeing <$0.30/Wh for some models now.
That said, if Energy Dome can achieve reasonable $/kWh at grid scale without the lithium supply chain constraints, the efficiency trade-off might be worth it. The real question is whether the mechanical complexity translates to higher maintenance costs that eat into any capex savings.
It's sort of like arguing for going back to steam engines because we've got a new way to boil water.
A large portion of power comes from new and exciting ways to boil water that turns a turbine ;)
Most fossil fuel plants are water boilers as are all nuclear plants.
There's even some solar power plants that are effectively just water boilers.
I'd mostly be wary of what the actual costs and operational experience are. This device has moving parts that a battery doesn't. Looking at their news page, I see announcements of projects and partnerships but I don't think that they have any completed projects running yet. I suspect that their CAPEX comparison, where they show lithium ion batteries as 70% more expensive, may be aspirational rather than demonstrated. There are several companies that have already installed megawatt-scale lithium ion grid storage today: Samsung, BYD, Tesla, Fluence, LG Chem... and many of these projects have published costs and operational experience already.
I'm skeptical of their cost claims. Turbines aren't cheap and compared to batteries, they require significant maintenance. And while you can increase energy storage by increasing the size/number of CO2 tanks, the only way to increase power output (or "charging" speed) is to add more/bigger compressors and turbines.
There's also the issue of volumetric energy density. Wikipedia says that compressed CO2 storage has an energy density of 66.7 watt-hours per liter, though it's unclear if that's before or after turbine inefficiencies.[2] And that's the density in a compressed tank. It doesn't count the volume of the low pressure dome, which is many times larger. For comparison, lithium batteries are 250–700Wh per liter depending on the chemistry. Specific energy (energy per unit mass) is better than lithium ion, but since these are fixed installations, mass isn't a major concern.
Considering their claims are for a theoretical full scale plant, and that the numbers are already worse than batteries (75% efficiency, lower volumetric energy density, $200/kWh), I'm not optimistic. This technology might have niche uses, but I don't see it competing with most lithium battery installations.
That said, I hope I'm wrong. The more energy storage solutions we have, the better our future will be.
1. https://www.energy-storage.news/energy-dome-launches-4mwh-de...
2. https://en.wikipedia.org/wiki/Compressed_carbon_dioxide_ener...
It also has to be pretty big, which doesn't matter too much other than a critical failure would be more impressive.
They say no leaks, but I'm sure there will be SOME CO2 leakage. Hard to make something like this with gases that doesn't leak at least a little. You could offset that with some CO2 capture via atmospheric distillation.