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.
> 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 290-300°C 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.
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.”
