Spent breakfast researching this:

• the plant would store 200 MWh
• given the 10-hour figure, one would assume it can feed up to 20 MW to the grid at any time
• they have already built a 4 MWh pilot plant in Italy
• the utility has also been building lithium-ion battery farms, so it stands to reason they see enough potential in this approach to continue pursuing it
• compressed CO2 storage has advantages over compressed air in that it can be stored indefinitely at ambient temperature and has a higher energy density in liquid form
• it has disadvantages in terms of plant safety