Design of hybrid renewable energy systems considering optimal real-time pricing

In remote islands in Japan, there is a need to introduce renewable energy to meet the demand, because the power system in these areas are basically composed of internal combustion generators from which the generated energy is expensive and it is not friendly to the environment nowadays. However, the uncertainty of renewable energy sources such as photovoltaic (PV) and wind generator (WG), makes it difficult to predict the output power of these resources. Hence, battery energy storage system (BESS) is being introduced. BESS is very effective equipment because it is possible to prevent the power output variation of renewable energy facilities through the charging and discharging of the BESS. Furthermore, demand response (DR) program is attracting attention as an effective instrument for energy management method. It can be divided into two main categories: time-based program and incentive-based program. This paper addresses real-time pricing (RTP) under the time-based program. It enables power supplier to control the load demand based on electricity prices. This paper presents the optimization method to determine the capacity of PV, WG, and BESS in 100% renewable energy small power systems and also indicates the effectiveness of optimal RTP.