Energy is one of the most basic elements of the universe that is essential for all life processes. The problem facing the world nowadays is the diminishing of fossil fuel resources and the increasing of emissions to the atmosphere, thus world attention is now going to the utilizing of renewable energy sources. The aim of this paper is to evaluate the potential fuel savings that could be achieved by integrating a parabolic trough collector solar power plant into an existing natural gas combined cycle in the city of Alexandria, in Egypt, where direct solar radiation levels are high all year, varying from 2,000 kWh/m 2 to 3,200 kWh/m 2. The Integrated Solar Combined Cycle (ISCC) has been modelled in Matlab, using Simulink to couple a control system that simulates the operation of the hybrid plant under fuel saving mode. The results show that the tested system achieves good fuel saving, reaching 436,000 $/year in case of controlling the amount of oil that passes in the parabolic collector and 165,625 $/year in case of not controlling the amount of oil with a percentage of 38 % of the first case.