Technologies related to the advancement of renewable energy are growing very fast. Development in renewable energy technologies, reliability, and environmental restrictions generates the requirement of a hybrid power system (HPS). Proper financial management is necessary to ensure the profitability and sustainability of any project. So, while planning a HPS an essential factor that should be taken into account is cost. This factor can be included in planning a HPS via pinch analysis through the concept of prioritization. This concept is a well-established technique in Process Integration for designing cost-optimal networks for recovery and conservation of resources such as heat, mass, water, carbon, gas, properties and batch, production. However, its application in planning HPSs still needs development. This paper extends the concept of prioritization for planning HPS to develop cost-optimal HPS. The cost of power generation depends on the type of power resource. The time of availability of each source is also taken into account. The methodology presented in this paper calculates the power rating of resources required for satisfying the power demands with the objective to minimize the overall cost of electricity in HPS.