Plan of hydrogen supply chain in Hakodate using offshore wind power in southern Hokkaido

In order to achieve carbon neutrality by 2050, it will be necessary to introduce renewable energies to supply electricity and heat. 2018, the share of renewable energies in Japan was about 17%, of which wind power accounted for 0.7%. Offshore wind power generation is attracting attention due to its superior wind conditions at sea compared to those on land, ease of scaling up, and low impact on people, such as noise. In this study, a 722 MW offshore wind power generation system is planned off the coast of Hiyama in southern Hokkaido to supply energy to the city of Hakodate. The proposed system will transmit the output power to a substation near Hakodate City via a transmission line. The transmitted power will be used to supply power according to the power load via the transmission line. The surplus power is used to generate and store electrolytic hydrogen. The stored hydrogen is used to stabilize the power supply using fuel cells when the power supply is insufficient. Considering the efficiency of each device, excess electricity was converted to hydrogen for storage and used to adjust the electricity supply, resulting in a supply that is more than 70% of the demand. Comparing the installation costs of hydrogen storage and storage batteries, storage is cheaper than storage batteries when the hydrogen tank capacity is 140,000 kg or more.