An assembly includes a gas turbine and a heat exchanger for heating up a gas turbine process fluid by thermal energy. The gas turbine has a compressor, a combustor and a turbine downstream of the combustor, wherein the thermal energy is from the solar receiver. To improve efficiency and reduce power generation fluctuations, the assembly includes a first line to conduct the gas turbine process fluid downstream a compression by the compressor to the heat exchanger, and a second line to conduct the gas turbine process fluid from the heat exchanger to the combustor to generate hot combustion gas from the warmed up gas turbine process fluid burning fuel in the combustor.