Spanish utility Iberdrola has inaugurated its ‘Tâmega Gigabattery’ in northern Portugal, a renewable energy complex including pumped hydro with an energy storage capacity of 40GWh.

Iberdrola has invested €1.5 billion (US$1.54 billion) in the facility which combines two run-of-river hydroelectric plants and an 880MW PHES unit (Gouvães), with a total combined hydroelectric power of 1,158MW. That will increase the electrical power capacity on the Portuguese grid by 6%.

The Tâmega electrical power production system can store 40GWh (40 million kWh), which makes it one of the largest energy storage systems in Europe.

The Portuguese prime minister António Costa and Iberdrola chairman Ignacio Galán inaugurated the project yesterday (July 18) morning, although a press release did not clarify exactly which parts of the complex are fully operational and grid-connected yet.

When the company turned on the first of Gouvães’ four 220MW turbines online in February, as reported on Energy-Storage.news, it said that Gouvães and one of the two run-of-river units would come online in mid-2022 while the second would start in mid-2024.

At full operations, the complex will also have 300MW of wind power, which will help power the PHES plant when it is pumping water up into the upper reservoir (i.e. charging).

Iberdrola has described the project as the “the largest clean energy project in Portugal’s history”.

It comes just a few weeks after Switzerland turned on its own large PHES project. The Nant de Drance plant cost CHF2.2 billion (US$2.3 billion) to build and has an energy storage capacity of 20GWh.