A vast array of 12,000 solar panels are set to become Europe’s largest floating solar park when they finish taking position atop the Alqueva reservoir this year.

Supplying a third of the electricity to the nearby towns of Moura and Portel—they look to continue taking advantage of Portugal’s exceptional year-round weather that has seen the nation become one of the leading renewable-powered nations in Europe.

Built by EDP, the country’s principal utilities provider, the panels will be mounted on pontoons in an area the size of four European soccer pitches, equipped with lithium-ion batteries to store a total excess of 1.5 gigawatts.

The advantage of floating solar is that it doesn’t take up limited land space in the small country. Unused electricity that can’t be used pumps water into the reservoir, which can be fed through the hydropower system of the dam to create additional power.

“This project is the biggest floating solar park in a hydro dam in Europe, it is a very good benchmark,” said Miguel Patena, group director for EDP who is in charge of the project.