Japanese manufacturers enter into cheap ‘green’ hydrogen tech

Japanese manufacturers such as Toshiba and Toray Industries are developing new technology that produces cheaper “green” hydrogen, part of efforts geared toward promoting the use of clean-burning fuel.

Green hydrogen, which is made with renewable energy, is typically produced with electrolyzers that break down water molecules into hydrogen and oxygen. Electrolyzers that use polymer electrolyte membranes (PEM) require electrodes containing iridium, a rare metal.

Only about 10 tonnes of iridium is produced globally in a given year, and price of the metal is now 2.5 times that of gold in the face of demand from the green hydrogen industry.

However, Toshiba developed a way to reduce iridium content by nine-tenths in PEM electrolyzers while maintaining the same output and durability. The company achieved this by devising an iridium oxide nanosheet catalyst.

Using less iridium will mean green hydrogen that is less expensive to produce. Japan has set a goal of having the cost of supplying hydrogen be 20 yen (14 cents) per cubic meter in 2050, down from 100 yen today

Hydrogen electrolyzers are expected to begin entering the mainstream in the middle of the decade. Through last year, the total capacity of electrolyzers installed was only about 1 gigawatts, according to the International Energy Agency. The capacity is expected to jump to 134 GW in 2030.

Toray has developed a higher-performing electrolyte membrane that uses hydrocarbons instead of fluoride. The membrane is also four times stronger.

The higher the production efficiency of a membrane, the lower the cost of hydrogen production. Toray has partnered with German company Siemens Energy, among others, to field test the membrane. Products with the new membrane are due to be released in the next two years.

Unlike Toshiba and Toray, Panasonic Holdings is looking to innovate alkaline electrolyzers. Such electrolyzers do not use expensive metals, so they too would reduce production costs.

Panasonic was able to increase hydrogen production efficiency by reducing the size of nickel and iron, both affordable metals, to nanometers to make a catalyst. In the future, it is possible that alkaline electrolyzers will surpass PEM electrolyzers in terms of production efficiency.

Discussions are underway with water electrolyzer manufacturers for trials in 2025.

However, alkaline electrolyzers are inferior to PEM types in terms of durability when used in conjunction with renewable energy.

Development of more efficient next-generation technology is also progressing, such as solid oxide electrolyzers that produce hydrogen from steam at 600 C to 800 C rather than liquid water. Water is split more easily thanks to the high temperature, making the machines 10% to 20% more efficient than other types.

Major auto parts producer Denso said early this year that it was developing solid oxide electrolyzer technology.