To assure a real penetration of the enormous intermittent and dispersed naturally renewable resources especially solar and wind, optimal sizing of hybrid renewable power generation systems provide evidence to be indispensable. A determinist technique has been developed to optimize the annual capital cost and the levelized cost of energy of a stand-alone hybrid generation system. Generation and storage units for three systems (wind, photovoltaic, and hybrid photovoltaic–wind turbine) are optimally sized in order to meet the annual load and minimize the capital annualized cost. A case study is conducted to analyze one hybrid project, which is designed to supply residential household located in Monastir city, Tunisia.