Spanish to produce green H2 under one euro only by using sun

HySun, a joint venture between Spanish companies Nanogap et Tewer Engineering, claims to be able to produce ‘white’ or ‘green’ hydrogen for one euro per kilogram or less by 2030 just by using solar energy. That would enable it to go under the price of ‘grey’ hydrogen produced from natural gas and used for 95% in Europe at a current price of 4,5 to 5,5 euros.

Its MM-CST photoreactor uses solar energy to extract the hydrogen directly from water, rather than needing an electrolyzer to do that with electricity. The SolHyd research project in Belgium created a different technology with combined ‘hydrogen-solar panels’ that extract hydrogen from the air.

Reaching 56% efficiency

HySun claims its technology can reach over 56% Solar To Hydrogen (STH) efficiency, while other techniques get only 10%. MM-CST stands for Metal Molecules with Concentration Solar technology and photo-thermo-catalytic materials and solar concentrators.

It combines the technology of Nanogap’s catalyst Metal Molecules, which are sub-nanometer in size and have unique catalytic properties, with Tewer’s solar reactors and concentrators. In the photoreactor, water is heated to steam using reflectors to bundle the sunlight and concentrate the heat. In the first step, and pure O2 is created, and in the second step, pure H2.

The Spanish call it ‘white hydrogen’ rather than ‘green hydrogen’, which gets its name from using renewable ‘green’ sources like wind and solar. The term white hydrogen refers mainly to naturally occurring H2 in underground deposits.

The photoreactor with its reflectors needs no grid connection, the Spanish say, and uses eight times less land surface than needed for a classic natural gas to hydrogen cracker installation at only half of the cost of the latter.

That enables them to compete directly with today’s cheapest form of grey hydrogen, which costs $2 per kg in the US, while in Europe, Australia, and Asia, it costs $5 to $6. The Spanish hydrogen technique can reach $1 to $3/kg with an annual production of 45 tons of H2 and $1/kg for 9 000 tons of H2/year.

HySun’s CEO, Marco Antonio Carrascosa, stated that the company plans to install up to 35 photoreactor sites of this type to produce more than 100 000 tons a year of renewable hydrogen by 2030 and reach a turnover of more than 130 million euros.

Belgian hydrogen-solar panel

Although the company claims its technology is perfectly scalable, it is still in its early development, and scalability has yet to be proved. That’s also the challenge of a Belgian project with similar aspirations to produce green hydrogen using pure solar energy but with a totally different approach.

At the TRANSfarm, a site near Leuven meant for up-scaling technologies developed at the Louvain University, the Belgian SolHyd research project has been readying since 2022 a 350 m2 production space for its hydrogen panel.

250 liters of hydrogen per panel

The panel, cast into an attractive industrial design by Comate Engineering & Design, can generate up to 250 liters of hydrogen from the moisture in the air just using solar energy. And just like solar panels, they can easily be installed on rooftops of houses and large buildings without needing large areas of land.

The top layer solar panel produces electricity, while underneath, a system of tubes extracts the hydrogen directly from the air using a membrane. The technique is called ‘direct solar hydrogen production’, and while several start-ups are experimenting with it, none landed as far as the Belgian researchers. They get it directly out of the air without using water as such.