Air conditioning system capable of converting waste heat into electricity

An air conditioning system includes an air conditioning unit (1) and an electricity generating unit (2). The air conditioning unit (1) includes an expansion valve (11), an evaporator (12), a compressor (13) and a condenser (14) that cooperate to form a first coolant circulating loop for circulation of a first coolant. The electricity generating unit (2) includes a heat radiator (22) disposed adjacent to the evaporator (12), a heat absorber (24) coupled to the heat radiator (22) and disposed adjacent to the condenser (14), a turbine (25) coupled between the heat radiator (22) and the heat absorber (24), and an electricity generator (26) coupled to the turbine (25). The heat radiator (22), the heat absorber (24) and the turbine (25) cooperate to form a second coolant circulating loop for circulation of a second coolant. The electricity generator (26) converts mechanical energy from the turbine (25) into electricity.