The fluid in high pressure storage is a liquid, making the storage much cheaper. Liquid N2 (most of air) would require over 40 times more pressure or cold temperatures. Purifying out CO2 or any gas is generally a negligible cost.
The fluid in high pressure storage is a liquid, making the storage much cheaper. Liquid N2 (most of air) would require over 40 times more pressure or cold temperatures. Purifying out CO2 or any gas is generally a negligible cost.