Danish wind turbine maker Vestas, Spanish energy company Naturgy, pipeline-operator Enagas and fertiliser-maker Fertiberia will also be part of the project in Aragon, northeastern Spain, with work expected to begin late next year.

Financial details were not disclosed of the plant, which will have capacity of 40,000 tonnes of hydrogen per year, or around 30% of Spain's current hydrogen demand.

"Spain and, concretely Aragon, offer very good conditions to develop this technology given the excellent wind and sun potential and the proximity to centres of demand," Soren Toftgard, a partner at CIP, said in a statement.

European policymakers and industry have been embracing hydrogen as a way to meet a European Union goal for net zero emissions by 2050, but critics say it can prolong the use of fossil fuels when the aim should be to get rid of them entirely and it requires large amounts of energy to produce.

Green hydrogen, produced using renewable energy, has the best environmental credentials of the various shades of the clean-burning fuel, which can also be produced using fossil fuel as the energy source to electrolyse water.

The partners in the Spanish project will set up a wind and solar plant with installed capacity of between 2 GigaWatts and 5 GigaWatts in Aragon to power a 2GW electrolyser.

The hydrogen produced will be shipped by pipeline south to Valencia where it will be used as raw material to produce fertilisers, CIP said.

(Reporting by Marta Serafinko, editing by Inti Landauro and Barbara Lewis)