A spin-off from the Karlsruhe Institute of Technology (KIT), Photreon, gained significant attraction at the Hannover Messe event, where it highlighted its hydrogen production technology and presented a new photoreactor panel.

The project showcased a one-square-meter prototype designed to generate hydrogen using only water and sunlight.

“We avoid the detour through electrically powered electrolysis, producing chemical energy from sunlight and water,” said photreon co-founder Paul Kant.

This system operates independently of the electrical grid and does not require the electrolyzers typically used in green hydrogen production.

By presenting this technology, the team demonstrated a method that could potentially lower the barriers to entry for decentralized hydrogen infrastructure.

Advances in photocatalysis and reactor design

Standard methods for producing green hydrogen involve two distinct stages: capturing solar energy via photovoltaic panels and then using that electricity to power an electrolysis unit.

Photreon’s approach replaces this two-step sequence with a single process known as photocatalysis. “Specially designed, light-sensitive materials absorb energy from sunlight, exciting electrons into an activated state,” said the team in a press release. 

This energy is then used to split water molecules directly into hydrogen and oxygen. This direct conversion method is intended to reduce the technical complexity and high system costs that have previously limited the widespread adoption of hydrogen fuel.

The mechanical design of the panels focuses on scalability and ease of manufacturing. KIT has filed a patent for the reactor’s internal geometry, which is specifically engineered to manage the interaction between light transport and chemical reactions while ensuring the hydrogen gas is removed efficiently.

“We designed the reactor geometry to optimize the interplay of light transport, chemical reaction, and removal of the reaction products, and we’re demonstrating that with our one-square-meter prototype,” added Kant.

Common materials and standard manufacturing processes

Because the design utilizes common materials and standard manufacturing processes, the panels are suitable for mass production. The modular nature of the technology means it can be deployed in small units on rooftops or expanded into large-scale arrays to form solar hydrogen farms in regions with high solar exposure.

“The panels can be used where supplying hydrogen has previously been too expensive or logistically difficult, for instance in medium-sized companies wanting to cover their future needs on-site (e.g. specialty chemicals, food production, or metalworking) or in large-scale solar projects in regions with abundant sunlight,” highlighted the team.

These panels allow such businesses to produce fuel on-site, reducing their dependence on external energy networks.

“In places without connections to power grids or a hydrogen network, our technology opens up new possibilities for local production,” concluded Maren Cordts, who is also a co-founder.

By enabling local production, the system provides a functional alternative for industrial sites that were previously considered geographically or economically unfeasible for green hydrogen projects.

As the energy sector moves toward decarbonization, this direct-to-fuel method offers a different trajectory for the hydrogen economy. The focus remains on making the production of clean energy more direct and less reliant on centralized infrastructure.