Hydroelectric power plants are the most essential and efficient renewable energy generation source. Hydropower is the world’s largest source of renewable electricity that can meet peak electricity demand and is also cost-effective in the long run.
Spain-based wind power producer and one of the largest power companies, Iberdrola is building the Alto Tamega Dam. Now the company has started the process of filling the Alto Tamega Reservoir.
The Alto Tâmega Dam is a 104.5 m high, 220,000 cubic meters of concrete, and 335 meters long, double-curved arch dam. The dam has a reservoir of 468 hectares and a volume of 132 cubic hectometres (0.1320 cubic km). This dam is located at Tâmega River in the municipalities of Ribeira de Pena and Vila Pouca de Aguiar in Vila Real District, Portugal.
When the dam will full, it will supply the water needed to generate renewable electricity at the Alto Tâmega power plant. It has two lateral channels with a combined discharge capacity of 1,825 cubic meters per second, which prevent the dam from overflowing.
The dam’s hydropower generation unit consists of two 80MW turbine units with a maximum flow rate of 200 cubic meters per second, generating 139GWh of electricity annually.
The dam’s construction has been done in 21 blocks, each divided into 2-meter-high sections. That helped completion of the concreting of the dam in less than two years and was completed at the end of 2022. When the Alto Tâmega Hydroelectric Power Plant was in the construction phase, the company employed over 1000 workers on the site.
During July month, the river diversion tunnel was closed. In the next three months, a 28-meter-long concrete plug will be constructed inside the tunnel to ensure the closure of the diversion tunnel for the entire life of the facility. In these three months, the river flow will continue through the dam’s base.
Iberdrola signed a 70-year concession with the Portuguese government in July 2014. The project is part of the wider Tâmega hydropower-generation group composed of 3 dams and three plants, including the Alto Tâmega, Daivões, and Gouvães dams. The other two dams, Gouvães generating 880 MW of electricity with pumped-storage plants, and Daivões generating 118 MW of electricity, are projects in commercial operation from 2022.
The civil work of the Alto Tâmega dam is practically complete, and the electromechanical assemblies will be completed by the end of 2023. After filling the reservoir in winter this year, the group’s first synchronization with the grid is scheduled for January 2024, and the dam will enter commercial operation in March 2024.
The Tâmega hydroelectric complex is one of the most significant energy initiatives in Portugal’s history, with a total investment of more than €1.5 billion ($1.639 billion) and an installed capacity of 1,158 MW, 880 of which are reversible.
The Alto Tâmega project is completed with the collaboration of Iberdrola with national and municipal authorities, local communities, and other state entities.