The kingdom of Saudi Arabia is a very vast area and has villages which are very far from the national power grid. Although Saudi Arabia has very high energy potentials from renewable energy resources such as solar and wind energy, diesel generators are still used to supply power for remote villages. However, the concept of an islanded micro grid (MG) is a new method of generating power which involves integrating renewable energy sources with appropriate energy storage technologies to supply power to an area. Optimizing the size of hybrid micro sources for an islanded MG with minimum capital and operational cost while achieving the targeted availability of power supply, is a challenging task. In this paper, typical meteorological data is analyzed using the forever power method. Many combinations of PV panels and wind turbines are generated with their all corresponding availabilities. The goal of this study is to allow the designer to select the size that best fits the targeted availability, cost, environmental benefit, and reliability. This method is applied to an islanded MG for four houses at a rural area near Yanbu City, Saudi Arabia.