Why is CO2 storage gaining traction as a grid-scale 'battery' and what does it mean for CO2 supply?

Why is CO2 storage gaining traction as a grid-scale 'battery' and what does it mean for CO2 supply?
CO2 energy storage is emerging as a viable long-duration storage technology, with projects in Italy (Energy Dome's 20 MW/200 MWh), China (Xinjiang, by Huadian and Dongfang Electric), and planned US/India sites. The system compresses CO2 to supercritical state during charging, stores it, then expands it through turbines to generate power, offering grid inertia that battery storage lacks. Market forecasts show long-duration storage growing from $3.1 billion in 2024 to $8.7 billion by 2034 (10.6% CAGR). For CO2 suppliers, this creates a new, non-consumptive demand: systems require initial CO2 fill and periodic makeup, but volumes are modest. The bigger implication is that CO2 storage could stabilize renewable grids, indirectly supporting higher CO2 capture rates and creating a circular value chain where captured CO2 becomes an energy carrier.