A thermal energy storage system is operable in heating capacity storage and discharge modes and cooling capacity storage and discharge modes for maintaining a temperature in a vehicle compartment. Each mode includes a thermal charging cycle and a thermal discharging cycle. The thermal energy storage system communicates with a vehicle air conditioning system including a compressor and a vehicle coolant system including a vehicle engine. The thermal energy storage system comprises a thermal storage apparatus housing thermal energy storage material that stores thermal energy. The thermal storage apparatus is connected to the air conditioning system and the coolant system so that a refrigerant or coolant flows through the thermal storage apparatus in heat transfer relationship with the thermal energy storage material.