29 November 2023

Electricity generation from pumped-storage dams sets new record

Hydropower generation from pumped-storage reached the highest annual value ever on 15 November, with 2.5 TWh, making 2023 the year with the highest production ever, and the year has not ended yet. The previous all-time high, 2.3 TWh, occurred in 2022. Among the most productive dams, Gouvães accounted for 35% of the total, while Alqueva and Venda Nova/Frades each contributed 20%.

Electricity generation from pumping is possible in dams equipped with hydroelectric pumps. These pumps lift water from a lower reservoir to an upper reservoir, allowing its "reuse" for electricity generation during periods of higher demand.

The use of hydroelectric pumps helps enhance supply reliability during dry periods and also facilitates the integration of other renewable energies such as wind and solar. It stores surplus production for use during peak consumption hours. The significant increase in pump usage over the last two years is directly related to the rise in photovoltaic generation. It allows for the absorption of surpluses during hours of abundant sunlight for later production during peak hours. In the coming years, with the increasing integration of renewables into the National Electric System, the use of pumps in hydroelectric power stations will continue to increase significantly.

Simultaneously with the increase in solar production in the Iberian Peninsula, the Gouvães hydroelectric power station, which started operating in January 2022, has expanded the installed pumping capacity in Portugal. Currently, the Portuguese National Electric System has an installed power in hydroelectric pumps of 3,585 MW, with a total hydraulic power of 8,216 MW. The all-time maximum power absorbed by the pumping power stations was 2,492 MW in January 2021. This year, the maximum reached so far was 2,474 MW, in the month of September.

These records confirm that Portugal has maintained a sustainable trajectory in the progressive integration of endogenous renewable sources, always prioritising the primary goals of security of supply and quality of service.