NOVELTY - The method involves feeding fuel stream (69) to gas turbine (5). A medium is compressed with external compressor to provide compressed medium. The compressed medium is extracted to provide cooling duty (18), after extracting of heat from the compressed medium. The gaseous hydrocarbon stream is cooled using cooling duty. The fuel stream is combusted in the gas turbine with chilled oxidizing stream (19). A solar power (17) is converted into chilling duty. The portion of chilling duty is applied for chilling of oxygen-containing stream (45).    USE - Method of cooling gaseous hydrocarbon stream such as natural gas stream.    ADVANTAGE - The combustion chamber of gas turbine can be used for combusting fuel stream in the gas turbine. The density of oxidizing stream is increased and gas turbine compressor is relieved from some of chilling duty, by chilling the oxidizing stream before feeding chilled oxidizing stream to gas turbine. Thus, power output of gas turbine can be maintained even with increasing ambient temperature, and amount of decline of power can be reduced. The use of solar power is selected for chilling of oxidizing stream, so that the gas turbine can be operated when there is no or not enough sunshine. Thus, backup power provision for powering additional chilling of the oxygen containing stream needs to be in place can be prevented. The increase of complexity of operation is avoided, by omitting backup power provision. The solar receiver is located in the vicinity of gas turbine maximum peak, so that the shaving effect can be obtained in avoiding gas turbine power loss due to conditions of high ambient temperature. Hence, the solar receiver can enabled to operate under the meteorological and day time conditions as the gas turbine.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for system for cooling gaseous hydrocarbon stream.    DESCRIPTION OF DRAWING(S) - The drawings show the schematic view of the gas turbine system.    Gas turbine (5)    Solar power (17)    Cooling duty (18)    Chilled oxidizing stream (19)    Oxygen-containing stream (45)    Fuel stream (69)