Worse efficiency, much higher (mechanical!) complexity, much more bespoke and slower to get installed.

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 efficiency concerns here are valid. For comparison, modern lithium power stations are hitting 90%+ round-trip efficiency pretty consistently now.

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.

https://gearscouts.com/power-stations

With the energy source (presumably solar/wind) being "free," efficiency isn't the most important thing. But the whole thing sounds sort of "Rube Goldberg" even if it works, batteries or supercapacitors or something like that are probably going to be a lot more reliable.

It's sort of like arguing for going back to steam engines because we've got a new way to boil water.