For a storage facility for 100 MW and 500 MWh capacity, the specific costs for cavern construction and surface facilities were determined. The following table shows these costs in relation to values of other storage methods.
Comparison of the specific costs of different electricity storage methods
LCOE - Levelised Cost of Energy
This is a standardized method for determining the electricity generation costs over the lifetime of a plant. In the case of storage, however, one should rather speak of LCOS - Levelized Cost of Storage. With costs of 5 - 8 EuroCent per kWh, a compressed air storage is in the same range as pumped storage or lignite-fired power plants. The storage costs were calculated for an efficiency of 70%.
Levelized Cost for different methods of electricity production