Iberdrola has connected one of the two turbines at the Alto Tâmega hydroelectric power plant to the Portuguese electricity grid.

This marks a significant milestone towards the full commissioning of the 1.16GW Tâmega hydroelectric complex.

Built on the Tâmega River, in the municipalities of Ribeira de Pena and Vila Pouca de Aguiar in the Vila Real district, the hydroelectric complex comprises three power plants.

The Tâmega hydroelectric complex includes the 160MW Alto Tâmega hydroelectric power plant, the 880MW Gouvães pumped storage power plant and the 118MW Daivões power plant. The latter two have been operational since 2022.

The Alto Tâmega power plant is at the base of the Alto Tâmega dam and features a large double-curved vault structure.

The dam is 105m high, incorporates 220,000m³ of concrete and has a crown length of 335m.

The second of Alto Tâmega's turbines will be connected next month.

The plant will commence commercial operation by the end of March, bringing the complex to its full 1.16GW operational capacity.

The Tâmega complex has been built with an investment of €1.5 bn ($1.6bn).

It will provide an energy reserve of 40 million kilowatt hours, enough to power 11 million people for a day.

Tâmega project manager Rafael Chacon Llorente stated: “In a context where storage capacity is key to enabling a decarbonised electricity system, maximising renewable energy production and ensuring its integration into the system, the Tâmega hydroelectric complex has enabled a 33% increase in Portugal's hydroelectric storage capacity.

“This increase in power represented an increase of over 60% in the volume of energy stored by pumping in 2023 compared to 2021.”