The deal will be announced on Tuesday on the sidelines of the United Nations climate conference in Madrid, a day before the new European Commission lays out its "European Green Deal" policy to make Europe the first climate-neutral continent.

The consortium includes EDF, Voith, and General Electric Hydro, as well as universities across Europe.

Hydropower can serve as a giant battery, providing a store of energy to balance intermittent renewable energy sources.

As big business grapples with reducing emissions, metal processors, such as Norsk Hydro are using hydropower to make products they can market as green.

Some environmental campaigners have warned against any expansion of hydropower because of its impact on biodiversity and river systems.

But many analysts say all solutions will be needed if the EU has any hope of neutralising carbon emissions by the middle of the century with investment running to trillions of euros.

Under the deal, the "XFLEX HYDRO project" will get funds to explore how hydropower can stabilise variable renewables such as wind and solar, the European Commission said in a statement.

Some of the technologies the consortium will test include a battery-turbine hybrid to improve the integration of renewables in Europe's electric grid.

(Reporting by Jonas Ekblom; editing by Barbara Lewis and David Evans)