Decarbonization of energy systems of Japan is expected to be effective to ensure energy security and mitigation of Green House Gas emission. Procurement of low carbon energy from fossil fuel with carbon dioxide capture/storage (CCS) and renewable energy, and its transport to Japan is considered economically preferable. Hydrogen is evaluated as the suitable career of low carbon energy and estimated to obtain more than 10% of the Japanese primary energy supply under the severe restriction of CO₂ emission. Policies of the Japanese government regarding hydrogen energy system is briefly introduced.

Obayashi has been working on various demonstrations of hydrogen so that new ideas can be used to create new values. In this report that the main hydrogen-related initiatives that we have been involved in so far.

This paper mentions activated anodes and gas effects on electrodes in electrolyte, current distribution, leakage current resulting from the electrolytic process, gas purity, and safety of the process during water electrolysis, which have a large impact on plant performance, with regard to the actual alkaline water electrolysis technology. When the plant operation is faced with day and night intermittent operation, the degradation of anode coating is remarkable. Although the safety is top issues in actual plant operation, unlike common sense images, the most dangerous condition is when driving a plant at a low load. It should be understood that low-energy operation is the most dangerous condition because it is easy to reach the explosion limit of hydrogen gas.

It is said that it is necessary to build a hydrogen-based society in order to realize carbon neutrality. However, the reality is that the social implementation of hydrogen has not progressed. In order to realize a hydrogen-based society, it is necessary to solve many issues, and for that reason, the Japan Hydrogen Association was established in December, 2020 as a cross-industry organization. This association is participated by many companies and organizations from various industries, and will accelerate the social implementation of hydrogen with an all-Japan.

In 2020, Germany, European Commission, and several other countries have announced hydrogen strategies and roadmaps. Especially for Europe, its hydrogen strategy announced in July 2020 is based on FCH JU’s hydrogen roadmap in January 2019 and Hydrogen Europe’s “2x40 GW Green Hydrogen Initiative” in April 2021. From 2020, European Commission started discussion on EU taxonomy, and its delegated act in April 2021 reviled its CO₂ threshold of 3 kg-CO₂/kg-H₂, which is lower than CertifHy threshold of 4.4 kg-CO₂/kg-H₂. Currently, Europe is working on the development of hydrogen pipeline.

Japan has been led hydrogen technologies development in last three decades, but world recognized hydrogen quickly and it is accelerating investments for the wide varieties of applications. Introduction of world recognition of hydrogen’s role in the NET ZERO/Carbon Neutral Society and current movement especially national strategies and financial movements. Author raises the importance of evaluating hydrogen in the society and it is the key for the investments and implementation. Hydrogen may involve and play more fundamental back born in the future renewable dominated energy systems. Also raises Japan wide hydrogen pipeline network as an example of backbone to materialize the Carbon Neutral Society in Japan.

This paper describes activities of “Kyushu University Hydrogen Project”, focusing on continuous efforts towards social implementation of hydrogen energy. The Ito Campus, the largest university campus in Japan, has been regarded as “Hydrogen Campus”, on which various hydrogen related facilities and systems are installed, including hydrogen refueling station since 2005, 3 types of fuel cell vehicles as official university cars, and various kinds of stationary fuel cell systems, for improving social acceptance of hydrogen energy. “Kyushu University Hydrogen Motor-Show”, taking place in March 2021, realized demonstration of various types of hydrogen mobility on our Hydrogen Campus. Education is set as an important aspect in such activities, including Department of Hydrogen Energy Systems for master and Ph.D. degrees, and fellowship programs offering various support programs to doctoral students.