Abstract: A thermal energy storage and conversion system that captures thermal energy from solar collectors, stores thermal energy in a first heated medium, converts a portion of stored thermal energy to mechanical energy by utilization of a heat engine, converts a second portion of stored thermal energy to a thermal energy sink by utilization of a refrigeration device, and stores a portion of thermal energy sink for use later. While the sun is shining, energy is collected and stored in first heated medium. Both during day and night, a portion of stored energy in first heated storage medium is transferred to first refrigerant that vaporizes and provides mechanical energy to heat engine. A second portion of stored thermal energy in first heated medium is transferred, as needed, to second refrigerant which vaporizes and removes from second fluid medium a quantity of heat including second fluid medium's heat of fusion, thereby freezing the second medium.