Electric pumping has become one of the key pillars for ensuring stability, efficiency, and sustainability in the Spanish electricity system, especially with the support of companies like Iberdrola. This technological advancement allows for the storage of renewable energy and the immediate response to demand, a fundamental aspect in the current context of energy transition. Many people are unaware of the operation and relevance of pumped storage plants, despite their impact ranging from the integration of renewable energy to combating droughts.
This article covers in detail how pumped hydropower works, Iberdrola's leading position, Spain's existing infrastructure, and future challenges. In addition, the environmental, economic, and social advantages of these types of plants are explained, as well as how they contribute decisively to the balance of our country's electrical system.
What is electric pumping and what is its importance?
Electric or hydroelectric pumping is a system that allows energy to be stored using water as an energy vector. It involves taking advantage of times when there is surplus electricity production, usually renewable, to raise water from a lower reservoir to one located at a higher altitude. When electricity demand increases, the water stored in the upper reservoir is released and drives turbines that generate electricity.
This mechanism turns pumping stations into real "giant batteries" for the electrical system. Thanks to this, It is possible to make the most of the energy from the sun and wind, which would otherwise be wasted during times of low demand.
Comparatively, pumping is much more efficient and cost effective than chemical batteries., and it does not generate polluting emissions, so its contribution to sustainability is essential.
Iberdrola: leader in electric pumping at national and international level
Iberdrola plays a leading role in the development of pumping technologies in Spain and around the world. The multinational electricity company has more than 13.100 MW of installed hydroelectric capacity, of which more than 4.400 MW correspond to pumping stations.
Iberdrola's commitment to the energy transition and sustainable management of water resources goes back a long way., which has been an essential part of its strategy since its inception. This commitment to innovation has positioned the company as a European leader in energy storage.
Iberdrola's main pumped storage plants in Spain include emblematic projects such as the Villarino power station In the Almendra dam (Castilla y León), the complex of Cortes-La Muela in Valencia (considered the largest pumping station in Europe), the power station ValparaÃso in Zamora and of Santiago Sil-Xares in GaliciaIn Portugal, the infrastructure of Gouvaes on the Tâmega River.
These facilities allow the generation of enough clean and renewable energy to supply millions of homes., while providing significant environmental and social benefits to nearby communities.
How a pumped storage hydroelectric plant works
The operation of a pumping station is based on the existence of two reservoirs located at different heights. During times of low electricity demand (usually at night or on weekends), the system's surplus energy is used to pump water from the lower reservoir to the upper reservoir, taking advantage of lower demand and lower energy prices.
Later, when demand increases and the price of electricity increases, the water stored in the upper reservoir is released and, as it falls through a penstock, generates energy by driving turbines connected to electric generators.
This cycle can be repeated as many times as necessary, optimizing the use of resources. In addition, modern power plants incorporate variable speed systems and advanced automatic control methods. that adjust the power and operation of the turbines to maximize efficiency and minimize environmental impact.
Advantages of electric pumping over other forms of storage
Pumped hydropower stands out from other storage technologies due to its high energy efficiency, reliability, and long service life. A pumped storage plant can achieve efficiencies close to 75%, much higher than those of conventional batteries. In addition, operational flexibility is maximum., as they can start or stop power generation in a matter of minutes.
These are facilities capable of storing large amounts of energy (tens of GWh)., something unattainable for most current battery systems. For example, the Cortes-La Muela complex can store up to 24 GWh, enabling continuous energy production for more than 16 hours.
Another key advantage is its contribution to the integration of intermittent renewable energy. such as solar and wind power, storing the surplus when there is excess production and releasing it when it is most needed.
Lastly, These infrastructures do not consume water in a net way, since the same flow is reused again and again between the two reservoirs.
Main pumping facilities in Spain
Spain has a significant network of pumped storage plants, with an installed capacity that places it among the European leaders. There are currently approximately 5.988 MW of pumping capacity distributed between pure and mixed pumping systems., with Iberdrola being the company with the greatest presence in this type of infrastructure.
Among the most relevant facilities we can mention:
- Cortes-La Muela (Valencia): The largest pumping plant in Europe, with a turbine capacity of 1.804 MW and pumping capacity of 1.293 MW.
- Villarino (Castilla y León): Power plant located at the Almendra dam, with 810 MW of reversible power.
- ValparaÃso (Zamora): Recent improvements have allowed the addition of 60 MW of new reversible capacity.
- Santiago Sil-Xares (Galicia): Innovative for incorporating a static starter and backup battery, with 50 MW of power and almost 3 GWh of storage.
- The Muela I and IIEquipped with seven reversible turbines, they allow generating and pumping water between an upper reservoir and the Cortes reservoir, overcoming a difference in level of 500 meters.
- Valdecañas (Cáceres): New plant commissioned with 225 MW of power and 15 MW hybrid battery.
The boost to these infrastructures allows Spain to confidently address the growth of renewable generation. and the new energy challenges posed by the National Integrated Energy and Climate Plan (PNIEC).
Innovation and technological optimization
The new needs of the electrical system require going beyond traditional hydraulic management models. Iberdrola is at the forefront of technological optimization of pumping stations, integrating advanced variable speed systems, computational models to manage higher power, and hybrid technologies with conventional batteries.
For instance, A 15 MW and 7,5 MWh battery has been installed at the Valdecañas plant., while in Santiago Sil-Xares an associated 5 MWh battery allows for a more agile connection to the grid. These innovations They allow the generated power to be adapted to variations in the level of the reservoirs and maximize operational flexibility, a key requirement for integrating large volumes of renewables.
Furthermore, the conversion of conventional hydroelectric power plants into reversible ones with variable speed turbines It represents a technologically mature option that reduces costs, minimizes development times and lowers environmental impact, since it takes advantage of existing infrastructure.
Electric pumping in the fight against climate change and droughts
Beyond storing energy, pumping stations play a key role in regulating water resources.Regulating reservoirs help store water during the rainy season and compensate for the deficit during periods of drought, preventing overflows and smoothing floods in coordination with the administrations.
The reduction of CO2 emissions is another of the great contributions of these technologies.For example, the implementation of the Valdecañas plant will prevent the emission of more than 200.000 tons of CO2 per year, thanks to the greater integration of renewable energy sources.
These infrastructures also They generate qualified employment and promote economic growth in rural areas, helping to establish a population and supporting local SMEs through contracts and subcontracts.
Future challenges: increasing storage capacity
Spain's National Integrated Energy and Climate Plan sets a target of 2030 GW of storage capacity by 22,5, of which hydropower will maintain approximately 14,5 GW. To achieve this, it will be necessary to multiply the current storage systems by seven., especially if we want to fully integrate renewables and reduce dependence on fossil fuels such as natural gas.
It is estimated that up to 12.000 MW of additional pumping capacity could be installed in Spain., primarily through the modernization of existing power plants or the connection of existing reservoirs. The costs of these developments would be very competitive, in many cases below €1.000/kW.
Future development will also depend on the Government establishing appropriate remuneration mechanisms for these technologies. in capacity auctions, recognizing the value they bring to the stability of the electrical system.
Social, environmental and economic impact
In addition to its energetic function, Iberdrola's pumped storage plants have a very positive impact on the socioeconomic environment.The direct and indirect employment resulting from the construction and maintenance of these infrastructures translates into opportunities for hundreds of families in the regions where they are located.
The effect on the local economy is multiplied, since Much of the investment benefits local businesses and suppliers.Furthermore, the improvement in water quality, the constant reuse of resources, and the low environmental impact of utilizing existing reservoirs and pipelines reinforce the sustainable nature of these facilities.
In addition, The lifespan of a pumping station is exceptionally long, which guarantees decades of service and makes them a particularly profitable investment for society as a whole.
Electric pumping has established itself as an essential technology for the stability and efficiency of the Spanish electricity system. Iberdrola's leadership, ongoing technological innovation, and the intelligent use of water resources allow Spain to confidently address the challenge of the energy transition and the massive integration of renewables. Beyond the generation of clean electricity, pumped storage plants provide significant social, economic, and environmental benefits, promoting local development and contributing to the fight against climate change and efficient water management. Without a doubt, pumped storage hydroelectric power will continue to gain importance in the coming years, not only as a "battery" for the system, but as a driver of progress and sustainability for the entire country.
