In response to global climate change, nations around the world have pledged to reduce their CO2 emissions, with many setting 2050 as a deadline for complete decarbonization. Japan has joined in this movement, setting a goal of 46% reduction by 2030, and carbon neutrality by 2050. For most nations this means cutting their use of fossil fuels like oil and coal and increasing clean renewable energy production.

In addition, the recent Russian invasion of Ukraine, and the subsequent disruption this has caused to global oil and gas supplies, has made it clear that energy security requires achieving greater self-sufficiency and developing multiple energy sources. Renewables, being much less dependent on extracted resources, are seen as an important factor in bolstering energy security.

The optimal energy mix for each nation depends on a wide range of circumstances, including geography, climate, infrastructure, economy, and existing technology. Japan’s mountainous terrain and deep coastal oceans make common energy sources like solar and offshore wind farms less feasible. Japan also lacks any domestic fossil fuel resources. Instead, Japan is investing in the development of hydrogen as an energy source for use in transportation, industry, power generation, and other applications.

Hydrogen is the lightest and most abundant element available, and when combusted with oxygen the only waste product generated is water. This makes hydrogen theoretically an excellent source of clean energy. Hydrogen also has an excellent energy density and a long storage lifetime, giving it an advantage over electric batteries when being transported. On the other hand, producing pure hydrogen requires chemical processes that can be energy-intensive or even polluting. Liquid hydrogen must be kept extremely cold (-253 degrees C), so shipping requires either specialized containers, or for the hydrogen to be combined as ammonia. These are challenges on which many research institutes and corporations are currently working on overcoming.

One of the more common ways of using hydrogen is in fuel cells. Rather than burning the hydrogen, electricity is produced by separating the hydrogen atom’s electron using a special catalyst. The hydrogen then reacts with oxygen to produce water as fuel cell’s only waste. Toyota has been doing significant work in developing hydrogen fuel cell vehicles (HFCVs) and their Mirai sedan is able to travel up to 700 km on a single tank, significantly further than most battery-powered electric vehicles.

Hydrogen can also be used to make more traditional fossil fuel plants burn more cleanly. By mixing ammonia, which is made up of nitrogen and hydrogen into the fuel at a coal-fired power plant, CO2 emissions can be significantly reduced. This can be used to extend the lifetime of existing coal power plants while still reducing overall emissions. This technique may be very important in developing nations, helping them to transition their energy production to low-emission methods without disrupting their economic growth.

The three main fields of research into hydrogen are the development of production methods, transport methods, and applications. By making hydrogen easier to produce, easier to transport, and usable in more situations, the overall cost of use will come down to the point where hydrogen is not just the environmentally sustainable choice, but the economical one as well.

There are many different methods for producing hydrogen, but most can be described as green and blue hydrogen. Green hydrogen is produced by electrolyzing water, separating the hydrogen from the oxygen from oxygen atoms. Breaking the molecular bonds requires energy, but when this is provided through solar, wind, or other non-polluting methods, then the full hydrogen cycle is zero-carbon. Green hydrogen produced this way is the ultimate goal of most renewable energy plants, but the current production scales are limited. The FH2R hydrogen plant in the town of Namie in Fukushima Prefecture is currently Japan’s largest, and at its launch was the world’s largest. Using a 20-megawatt solar farm, it produces up to 1,200 Nm3 of hydrogen every hour without releasing any CO2.

Blue hydrogen is currently seen as the best course for large scale production of hydrogen in the near future, but it is not a perfect solution. Blue hydrogen production uses methane from natural gas, biomass, or other sources. Methane is a single carbon atom surrounded by four hydrogen, so this method strips away methane’s hydrogen, storing it directly or converting it to ammonia for easier transportation. Blue hydrogen leaves behind carbon, however, which must be captured and sequestered in some way. Japan has conducted successful research projects into carbon capture, but deployment at the scales necessary to have an impact on global emissions is still in development.

Transport systems for hydrogen are also needed for it to be a viable energy source, and Japan is also in the forefront of developing these innovations. Liquid hydrogen transport is, in theory, similar to transporting liquid natural gas (LNG). Hydrogen, however, is liquid at a much lower temperature than LNG, and its molecular size is significantly smaller. These differences mean that new materials and systems need to be developed to carry it safely and reliably. In 2021, Kawasaki Heavy Industries, Ltd. launched the Suiso Frontier, the first tanker ship for transporting liquid hydrogen, which can carry up to 75 tons. In a recent press release, the company announced their plans to produce 80 of the ships.

Japan has also been putting a hydrogen infrastructure into place to directly connect production sites, distribution centers, and consumers. In 2014, the world’s first commercial hydrogen filling stations were opened in Japan, and the number has now grown to approximately 160, operated by several different providers. An infrastructure network of underground hydrogen pipelines was also put in place in the International Olympic Village for the 2020 Games, and this network is scheduled for expansion in the near future.

Finally, widespread applications for hydrogen are needed for the fuel to gain widespread acceptance and for costs to come down through economy of scale. Residential fuel cell systems are also in use in a number of “smart communities,” but the largest applications in the near future are in transport and heavy industry. Hydrogen fuel cell automobiles have been steadily gaining ground in Japan, and hydrogen-powered buses are already in operation in Tokyo and other cities. Trucking and other industrial vehicles are also a high-potential sector for conversion from fossil fuels to fuel cells.

Looking Ahead to Global Cooperation