Iberdrola connects one of Europe’s largest pumped storage plants


Portugal – Iberdrola has synchronized the first 220-MW turbine at the Gouvaes hydroelectric power plant, delivering clean power to the grid for the first time, in collaboration with the Portuguese government.

With a €1.5 billion investment, the Tamega complex is one of Europe’s largest energy storage facilities. On the Tamega river, a tributary of the Douro, it consists of three reservoirs (Gouvaes, Daivoes, and Alto Tamega) and three hydroelectric power plants with a combined capacity of 1,158 megawatts (MW). The Gouvaes and Daivoes plants have now been completed after eight years of construction, and all of the generating units are currently undergoing commissioning tests.

Meeting energy needs in Portugal

Tamega will be able to produce 1,766 GWh per year, which will be sufficient to meet the energy needs of nearby municipalities as well as the cities of Braga and Guimaraes. The large Tamega giga battery will have enough storage capacity to supply two million Portuguese households for an entire day when the Gouvaes and Daivoes plants are fully operational in the middle of this year, contributing to the Portuguese government’s decarbonization and energy independence goals. With the commissioning of Alto Tamega in 2024, the facility will be fully operational.

Furthermore, this infrastructure will offset 1.2 million tonnes of CO2 emissions each year and diversify electricity generation sources while reducing reliance on fossil fuels.

Boost for region’s economy

The creation of this giga battery is boosting the region’s economic activity and employment. During the construction phase, 3,500 direct jobs and 10,000 indirect jobs were created, with 20% of the indirect jobs coming from neighboring municipalities. Over 100 companies have contributed to the project, with 75 of them being Portuguese. Iberdrola’s commitment to a sustainable energy model, which began two decades ago, is exemplified by this major clean energy project. The Tamega complex has benefited from the Portuguese government’s stable regulatory and macroeconomic environment.

Adding pumped storage capacity

The Tamega giga battery will add 880 MW of pumped storage capacity to Portugal’s electricity system, a 30% increase over the country’s current storage capacity. The electricity system is strengthened by reversible turbines and pumped storage plants. During periods of low demand on the electricity grid, energy is stored by pumping water from a lower reservoir to a higher one.

When there is a high demand for electricity, the complex can quickly release stored water and generate large amounts of electricity. All of this occurs without emitting any pollutants into the atmosphere. This hydroelectric technology provides network stability and plays a key role in the energy transition that will lead to the decarbonization of the economy as a backup to other renewable energy sources such as wind or solar photovoltaic.