Iberdrola España Increases Valdecañas Capacity By 355 MW And Adds 210 GWh Of Storage To Strengthen Renewable Integration

Iberdrola España has advanced its energy storage strategy on the Tagus River by implementing major technological upgrades at the Valdecañas pumped-storage power station in Cáceres. These improvements have increased the system’s generation capacity by 355 MW and added 210 GWh of storage, significantly enhancing renewable energy integration and strengthening grid stability.

The facility has already completed its first pumping operations, demonstrating the effectiveness of this large-scale “gigabattery,” which links the Alcántara and Valdecañas reservoirs—two of the largest in Europe. This configuration allows the system to absorb excess energy from intermittent renewable sources such as wind and solar, storing it for periods when production drops and electricity demand increases.

As part of its new setup, Valdecañas now incorporates a hybrid battery system with a power rating of 15 MW and a storage capacity of 7.5 MWh. Together with the hydropower upgrades, this brings the Tagus system’s total storage capability to approximately 210 GWh. According to the company, this amount of storage is comparable to the annual electricity consumption of 60,000 households, the capacity of more than four million electric vehicle batteries, or over two weeks of total electricity use in Extremadura.

This expanded capacity is expected to play a key role in managing demand during periods of high energy consumption.The project also benefits from the coordinated operation of the Valdecañas, Torrejón, Alcántara, and Cedillo reservoirs, complemented by pumping operations along the Tiétar tributary.

This integrated management approach supports flood control by regulating peak flows, helping to protect surrounding communities while preserving ecosystems and ensuring the availability of strategic water reserves throughout the year. The Torrejón–Valdecañas system essentially functions as a giant hydraulic battery, using surplus renewable electricity to pump water to a higher elevation when production is abundant, and later releasing it to generate electricity when demand rises.

This mechanism enables the storage of surplus renewable energy, reduces reliance on CO₂-emitting generation during peak periods, and optimises water distribution across reservoirs based on rainfall patterns and capacity needs. The company emphasises that all upgrades were completed within an electromechanical scope, involving equipment modernisation and operational enhancements.

No new civil works were conducted, reservoir levels remained unchanged, and existing transmission lines were fully reused, ensuring minimal environmental impact and efficient project execution. The Valdecañas upgrade aligns with Iberdrola España’s broader commitment to advancing energy storage as a central element of the energy transition.

Alongside efforts to expand renewable generation and develop smart grids, the company continues to invest in both large-scale pumped-storage systems and battery-based storage technologies. In Extremadura alone, Iberdrola’s hydroelectric facilities have a combined capacity of around 2,000 MW, and across Spain the company operates more than 4,200 MW of pumped-storage hydropower.

As Spain continues its shift toward renewable sources such as wind and solar, storage solutions of this scale are increasingly essential for ensuring system balance and optimising energy use. The company notes, however, that the development of new pumped-storage infrastructure will depend on long-term water concessions and stable revenue mechanisms that can support sustained investment and operational viability.