Abstract
This paper obtains the optimum size of wind turbine/PV /fuel cell hybrid renewable power system (HRPS) using both Artificial Immune System (AIS) and HOMER software. The AIS is based on Clonal Selection Algorithm (CLONALG). The optimum size of the hybrid system will achieve two goals; satisfy the load demand with least loss of power supply probability and have to minimize the overall cost of the whole system. The cost of the optimum hybrid system includes initial, replacement, operating and maintenance cost (O&M) and salvage cost which are calculated during the whole lifetime of the project considering a discount factor. The hybrid system is determined to feed an electrical load at located at Qena AL-Gadeda City in Egypt using its predicted solar irradiation and wind data.