Design and analysis of a 100% renewable energy system for Akita prefecture, Japan

This study aims to design and analyze a 100% renewable energy system for Akita prefecture in Japan. Hourly wind power potential, hourly electricity demand, and annual heat and transportation demand are estimated. The surplus electricity is stored in a battery, used to produce hydrogen, or exported to other prefectures. The hydrogen produced is utilized to meet middle- and high-temperature heat demand in the industrial sector and in freight transportation. The results show that the annual wind power potential is 35.2 TWh/year, which is larger than the electricity demand of 11.3 TWh/year. However, batteries are needed to cover the mismatch between supply and demand for more than 1000 h a year, and the capacity required is 48.4 GWh. The use of batteries not only to cover this shortfall but also to produce hydrogen increases the availability of batteries and water electrolysis. Furthermore, it leads to a 57% reduction in electricity costs and a 32% reduction in total costs. & COPY; 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).