A CO 2 energy storage system includes a storage tank that stores a CO 2 slurry, including dry ice and liquid CO 2 , at CO 2 triple point temperature and pressure conditions. The storage system also includes a first pump coupled in flow communication with the storage tank. The first pump is configured to receive the CO 2 slurry from the storage tank and to increase a pressure of the CO 2 slurry to a pressure above the CO 2 triple point pressure. The energy storage system further includes a contactor coupled in flow communication with the first pump. The contactor is configured to receive the high pressure CO 2 slurry from the pump and to receive a first flow of gaseous CO 2 at a pressure above the CO 2 triple point pressure. The gaseous CO 2 is contacted and then condensed by the melting dry ice in the slurry to generate liquid CO 2