Spanish energy companies Repsol and Enagas have developed a new technology that can produce green hydrogen through the direct use of solar energy without the need for electrolysis.

The roadmap for the technology, called photoelectrocatalysis, sees it competing on cost with both green and blue hydrogen by 2030, according to Repsol.

“The device receives direct solar radiation and, using photoactive material, generates electrical charges that cause the separation,” says Maria Dolores Hernandez, co-leader of the project, which Repsol began researching in 2021.

“It is a very disruptive technology” Sanchez, Enagas

This resulting simplification of infrastructure and equipment will reduce the capital cost of the technology relative to electrolysis-based systems.

The technology is more efficient than electrolysis as it avoids the losses associated with the transport and transformation of electricity.

And it has the advantage of not being subject to fluctuations in electricity prices—a key component of green hydrogen production costs.

“It is a very disruptive technology. It is part of our commitment to renewable gases, particularly hydrogen and biomethane, as keys to achieving the carbon neutrality that we want to reach at a European level, and specifically as a company, by 2040,” says Monica Sanchez, hydrogen coordinator at Enagas.

The next step will be the launch of a demonstration plant in 2024 at Repsol’s Puertollano industrial complex with a production target of 100kg/d of green hydrogen. Phase two is the installation of an industrial-scale plant in 2028 at the same location with a capacity of 10t/d.

10t/d – Target production in 2028

Repsol and Enagas have so far invested €8mn ($9.4mn) in the project, which has also received support from the European Commission’s Innovation Fund. The two companies have created a joint venture into which they plan to incorporate other investment partners with the aim of accelerating the industrial roll-out of the technology.

“The idea is to attract engineering and industrial companies to work together with us in the scaling up and industrialisation of the photoelectrocatalysis technology,” says Sanchez.

“Spain, due to its strategic position, is expected to become one of the future exporters of renewable hydrogen to other markets in Europe that do not have the same solar energy potential.”

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Author: Stuart Penson