Powerful energy storage systems are required to cover the increasing demand for cooling for air conditioning with renewable energies. Ice is an excellent phase change cold storage material. The energy density is high, so that considerably less space is required. The material costs are low. Freezing and melting are not subject to any degradation. The melting/storage temperature is constant, so that no stratification has to be ensured in the storage tank. Variable cold water return temperatures are not a problem. Ice slurry, which is produced using the triple-point process (vacuum ice), also overcomes the disadvantages of previously used ice storage tanks. The ice slurry can be pumped. No heat exchanger is required in the ice store. The storage geometry is variable. Antifreeze is not required. Water can be used in all circuits. Energy efficiency is high, as the evaporation temperature of the refrigerant during ice production is only 0 to −1 °C. In recent years, several vacuum ice slurry-based cold storage systems have been installed at various users. The ice production and thus storage capacity of these systems is 180…500 kW, the storage capacity up to 9000 kWh. The systems are used for load management or for storing renewable energies. One system even has a dual, seasonally switchable use: Cold storage in summer, heat extraction from cold river water in winter. The process principle is explained, results and experiences from the implemented systems are shown and the latest development of an 80 kW ice generator is presented.