Iberdrola connects to the grid the first group of the Tâmega gigabattery, one of the largest pumping projects in Europe

Iberdrola has commissioned the first group of the Gouvães hydroelectric power plant - a 220 MW capacity turbine - and has begun delivering clean electricity to the grid from the Tâmega gigabattery.

The Tâmega complex comprises three reservoirs (Gouvães, Daivões and Alto Tâmega) and three hydroelectric power plants with a capacity of 1,158 megawatts (MW) on the Tâmega river, a tributary of the Douro, located in northern Portugal, near Porto. 

After eight uninterrupted years of construction work, the construction of the Gouvães and Daivões plants has been completed, where the commissioning tests of the different energy groups are currently being carried out.

Tâmega will be capable of producing 1,766 GWh per year, enough to meet the energy needs of neighbouring municipalities and the cities of Braga and Guimarães (440,000 households). In addition, this large renewable infrastructure will have sufficient storage capacity to serve two million Portuguese households for an entire day and will contribute to the decarbonisation and energy independence objectives set by the Portuguese government. In 2024, with the entry into operation of Alto Tâmega, the construction of the facility will be completed.

In addition, this infrastructure will put an end to the emission of 1.2 million tonnes of CO2 per year and diversify production sources, avoiding the import of more than 160,000 tonnes of oil per year. 

The development of this gigabattery is fostering economic activity and employment in the region, since during the entire construction phase it has been estimated that up to 3,500 direct jobs and 10,000 indirect jobs will be created - 20% of which come from neighbouring municipalities - through more than 100 suppliers, 75 of which are Portuguese.

This major project has been possible thanks to Iberdrola's firm commitment to a sustainable energy model, which began two decades ago, and to the environment of regulatory and macroeconomic stability created by the Portuguese government.

In such a complex period, dominated by the pandemic, Iberdrola's engineering and construction teams, supported by suppliers, contractors and the administration, have continued to work tirelessly to incorporate new renewable capacity into the grid.

In addition, Iberdrola launched a socio-economic action plan for the area of influence in 2014, aimed at promoting social, cultural and environmental initiatives. These are already bearing fruit in the seven municipalities benefiting from the project: Vila Pouca de Aguiar, Ribeira de Pena, Boticas, Chaves, Cabeceiras de Basto, Montalegre and Valpaços. In fact, the project's Environmental Impact Statement (EIS) also includes the reforestation of more than 1,000 hectares, the planting of 17,000 cork oaks and actions to improve the populations of protected fauna and flora in the area.

The Tâmega gigabattery will provide 880 MW of pumping capacity to the Portuguese electricity system, an increase of more than 30% over the megawatts of pumping currently available in the neighbouring country.

Pumping plants are a safeguard for the electricity system, as they allow energy to be stored by raising water from a lower reservoir to a higher one. This means that a large amount of electricity can be generated quickly by turbining the water downstream to the lower reservoir. And all this without generating any pollutant emissions into the atmosphere.

Thus, the surplus energy in periods of low consumption is used to pump water from a lower reservoir to a higher reservoir, obtaining high quality energy that can help cover the needs of the market during peak demand hours.

In this way, pumped hydroelectric technology is key to guaranteeing the stability of the electricity system in the face of the intermittency of other renewable energy sources, such as wind or solar photovoltaic, which are set to play a key role in the energy transition that will lead to the decarbonisation of the economy.

Iberdrola is a leader in energy storage with 4,500 MW of installed capacity using pumped storage technology - not yet including this facility. The company expects to reach 90 million kilowatt hours (kWh) of storage capacity in 2022, which will represent an increase of almost 30% compared to 2018: 20 million kWh more, equivalent to 400,000 electric car batteries or 1.4 million batteries for residential use.

Hydroelectric plants such as Tâmega are a safeguard for the electricity system. The largest such facility in Europe is the Cortes-La Muela complex in Valencia.