Capacity Planning and Economical Evaluation of a Renewable Power System for Remote Island

Abstract

This paper presents capacity planning and economical evaluation of a renewable power system proposed for Okushiri Island, which is a remote island in the southwest of Hokkaido. In this system, the power demand is mainly provided by photovoltaic, wind turbine. Batteries are used as short time energy storage, and a hydrogen storage system (composed of water electrolyzer, hydrogen storage, and fuel cell) is used as long time energy storage. Optimal capacities of these power sources are those meet the required supply reliability, with the lowest cost. As the first step in the capacity planning, mathematical models for characterizing components are explained. The second step is to optimize the capacities of components. The configurations, which meet the required supply reliability with the lowest cost, give the optimal choices. These calculations are carried out with hourly meteorological data and energy demand data of Okushiri Island. As a result, hybrid storage (battery and hydrogen) is the best choice for Okushiri Island when high supply reliability is required. In the range of loss of power supply probability 0.1 to 0, the levelized cost of energy will be about 70-150yen/kWh.