Abstract: A complete hybrid system including a photocelland a wind turbine with battery storage is modeled, and the best approach forsizing the system to meet the electrical energy needs of a residential buildingis investigated. In evaluating system performance, the city of Tehran is usedas a case study. Matlab software is used for analyzing the data and optimizingthe system for the given application. Further, the price of the system design isinvestigated, and shows that the electrical cost of the hybrid system in Tehranis 0.62 US$/kWh, which is 78% less expensive than a wind turbine system and 34%less expensive than a photovoltaic system.