Spanish island builds ‘gigantic water battery’ to increase energy security

Gran Canaria is perhaps best known for its sandy beaches, perpetual sunshine and volcanic past. But far isolated from mainland Europe, the island relies heavily on imported fossil fuels to power its growing economy – 76% of its electricity comes from burning oil.

In an effort to go carbon-free, the government has invested heavily in renewable energy to harness the island’s abundant wind and solar resources. In 2022, renewable energy sources made up 24% of the island energy mixup from just 12% in 2018. But as more renewable energy sources come online, the island has another problem: storage.

Last year the government invested €400 million in the very first energy storage system in the Canary Islands, to stabilize the grid when the wind isn’t blowing or the sun isn’t shining. However, no battery packs will be built in this project, but two existing dams will be converted into one gigantic water battery.

Salto de Chira, as the project is called ‘pumped hydropower’, will pump water from the Soria dam to the Chira dam – which is higher up – during periods of low energy demand. During periods of high energy demand, water will be discharged from Chira, through a tunnel, over a set of turbines and back to Soria. And the cycle continues.