by Leigh Collins, Editor, Hydrogen Insight

The company, which has a unique ‘decoupled’ electrolysis system, has signed a non-binding agreement with Spanish renewables developer Sun Systems to co-develop the facility

Israeli electrolyser maker H2Pro has signed a memorandum of understanding (MoU) with Spanish renewables developer Sun Systems Group to build a 150MW off-grid solar-powered green hydrogen project in northeast Spain.

H2Pro has developed a novel “Decoupled Water Electrolysis” system that works in a unique two-step process, splitting water molecules into hydrogen and oxygen at different times from the same bi-functional electrode.

The unnamed project in Tarragona will be developed in stages, starting with a 25MW electrolyser producing 1,250 tonnes of green H₂ annually, before expanding to 150MW by 2032.

“H2Pro develops electrolyzers specifically designed to integrate with variable renewable energy sources. The company’s technology enables hydrogen production to follow the availability of renewable electricity, supporting an operating model based on dedicated off-grid photovoltaic generation.

“The Tarragona project will apply this approach at industrial scale, creating a pathway to capture low-cost solar energy when it is available and convert it directly into green hydrogen.”

Sun Systems will supply the solar power for the electrolysers from a nearby project with up to 220MW of photovoltaic capacity.

Hydrogen produced by the Tarragona facility “will initially be supplied to industrial users and injected into Enagás’ natural gas transportation network through blending”, says H2Pro.

“The project has also been designed to align with the future deployment of Spain’s dedicated hydrogen backbone and the H2Med corridor.”

In March, H2Pro announced plans to co-develop a green hydrogen project in southern Spain.

How H2Pro's novel 'decoupled' electrolyser technology works

H2Pro has developed a novel “Decoupled Water Electrolysis” system that works in a unique two-step process, splitting water molecules into hydrogen and oxygen at different times from the same bi-functional electrode.

In the first step, electricity produces hydrogen at the electrode, and a second “counter-electrode” acts like a charging battery. The electrical current is then reversed, flowing from the counter-electrode back to the bi-functional electrode, where oxygen is produced.

This eliminates the need for expensive membranes to separate the two gases, and makes the electrolysis process safer by ensuring that H2 and O2 cannot mix (which can potentially cause explosions).

As it’s a two-step process, there is also no issue with using the intermittent power provided by renewables — some conventional electrolysers struggle with intermittent power as turning them on and off can cause membrane and system degradation.

This eliminates the need for expensive membranes to separate the two gases, and makes the electrolysis process safer by ensuring that H2 and O2 cannot mix (which can potentially cause explosions).

As it’s a two-step process, there is also no issue with using the intermittent power provided by renewables — some conventional electrolysers struggle with intermittent power as turning them on and off can cause membrane and system degradation.