Earlier this year, the Japanese auto giant, Toyota, presented its hydrogen fuel cell vehicle, the Toyota Mirai, at the Auto Expo 2023 event in Greater Noida, and it has also been working on a new vehicle with a hydrogen combustion engine.

Now, a review article by a team of researchers, supported by the Toyota Mobility Foundation (TMF), has been published in the International Journal of Hydrogen Energy, a world-renowned scientific journal issued by the Dutch academic publisher, Elsevier.

This review article investigated a wide range of issues for each major water electrolysis method, such as restrictions on using renewable energy as a power source for water electrolysis, the durability of water electrolysers and catalyst degradation. It then described the performance requirements for water electrolysis systems and materials that can adapt to renewable energy fluctuations and the issues that need to be discussed going forward.

TMF has positioned environmental and energy issues as important themes for a sustainable mobility society, and in 2017, established the "Research Program to Support Innovative Hydrogen Energy Solutions", which targets carbon-free hydrogen (green hydrogen) cost reductions across the entire hydrogen supply chain of "producing", "transporting", and "using". In this programme, 29 promising research themes have been selected and given grants through open calls over three years. Additionally, regular evaluations and advice by an evaluation committee of experts in hydrogen and energy systems and opportunities for exchanges and mutual study among selected researchers have been provided.

In October 2020, the Japanese government made a "Carbon Neutrality by 2050" declaration. For realising a decarbonised society, in addition to supporting basic research by individual researchers, in April 2021, TMF started a new joint research programme to be conducted by teams of researchers. In this joint research programme, two working groups (WG) were formed to focus on two important themes for realising a decarbonised society, "Hydrogen Society & Energy Systems" and "Water Electrolysis". Five researchers for each WG were selected under the "Research Program to Support Innovative Hydrogen Energy Solutions".

Based on information obtained by conducting literature reviews on the impact of renewable energy power fluctuations on water electrolysis systems, the research team started research using a practical water electrolysis device installed with the cooperation of the National Institute of Advanced Industrial Science and Technology. The results of this study are expected to contribute to solving problems related to improving performance and reducing the costs of water electrolysis.

Other hydrogen-powered vehicles currently available are the Honda Clarity Fuel Cell and the Hyundai Nexo SUV. It is said that there are currently about 15 000 hydrogen-powered vehicles on US roads.