In the southern part of Libya, there are a number of power plants and other large industrial developments using their power systems, such as petroleum fields. Gas turbines are frequently employed due to water scarcity in the region, such as the Asrir field power plant. However, fuel transportation is one of the main difficulties regarding cost and safety. The annual cost of fuel operation and transportation is admitted to be very high; therefore, this work aims to utilize solar energy potential to reduce fuel consumption. In this context, a power plant that is currently in operation in Libya, which is located close to the Sahara Desert in the southwestern region, was selected as a case study. The region was chosen because it offers extraordinary conditions for the establishment of concentrated power plants. Simulations studies were carried out at full load considering the nature of the solar flux that varies with the meteorological conditions and the thermodynamic calculations were made based on algebraic equations describing the power cycle and the solar field. In addition, the feasibility of fulfilling the power cycle's energy required using the CSPs system was also analyzed. The annual behavior of the solar field was determined using hourly data within the system advisor model (SAM) software. In order to examine the possibility of fuel reduction, the cost of fuel was linked with an exergy analysis from an economic perspective. The findings revelated that the plant efficiency could be increased and the fuel mass rate ratio could be reduced by preheating the air temperature entering the combustion chamber. The air/fuel ratio at the combustor was found 43, the design heat energy required to deliver to the combustion chamber is 414.4MW, and the energetic thermal efficiency of the power cycle is 32.6%. The thermal power design of the solar field is 532MW when average direct irradiation is equal to 1000kWh/m².