Spain needs store renewable energy. It happens that neither the sun shines with the same intensity every day nor the wind always blows with the same force. The consequence is that supply does not always correspond to demand. Either too much energy is generated or not enough.
The question seems clear. We have to accumulate the surplus so as not to lose it. This way we can use it at times of greatest consumption. He storage It is the missing piece in the puzzle of the energy transition. Not in vain, the International Energy Agency (IEA) estimates that global energy storage capacity must increase fivefold, from 272 GW available in 2023 to 1,503 GW in 2030.
The Ministry’s plan is to accumulate 22.5 GW in 2030 and 30 GW in 2050. But there is still a long way to go to reach those figures, since the country currently has around 8 GW stored. Where is the greatest opportunity for growth? In the swamps of Spain and in the battery technological advancement.
Currently, pumped hydro and large-scale battery storage are the two most advanced technologies we have for “storing” wind and photovoltaic energy. Pumping is carried out in the reservoirs, through hydroelectric plants. At times of low electricity demand, the difference in height between two reservoirs of water is used to generate electricity, a cycle that can be restarted by returning the water to the upper reservoir.
Hydraulic pumping, which today provides almost 85% of the electrical storage capacity installed in the world, is “one of the most viable and efficient solutions for storage energy on a large scale and for long periods. Pumping provides exceptional flexibility to the electrical system in managing the fluctuations inherent to wind and solar generation to ensure a reliable and continuous supply,” explains Carlos Gutiérrez, Technology Manager at Repsol Renovables.
In Spain, one of the projects most notable hydraulic pumping is that of Aguayo IIin Cantabria. Repsol’s objective is the repowering of a 360 MW hydroelectric plant (Aguayo I), in operation since 1983, where new water pipes and equipment would be installed underground that would allow the capacity of both plants to be increased to 1,360 MW.
The other option (which can also be located in the pumping plants themselves) is to advance in the installation of gigantic batteries to store the surplus produced by renewable energy sources, a technology that may experience rapid growth in the coming years thanks to the development of lithium-ion batteries.
In Spain this sector is just getting started and “there are only 5 MW installed, although a series of projects totaling 6.5 GW have already been granted permission to access the electrical grid. If the decline in costs continues and regulation promotes a market that makes these assets profitable we can see a very important entry of projects in 2026-27“says Luis Marquina, president of the Business Association of Batteries, Batteries and Storage. Something that represents an opportunity because “a renewable energy ecosystem with adequate storage can make us the country in Europe with the most competitive electricity prices“.
The case of Spain
Spain is well on its way to being a leader in the generation of renewable energy. In 2023, 50.3% of the energy used came from renewable sources according to Red Eléctrica data; a record number to date. The goal of the Ministry of Ecological Transition (Miteco) is that renewable sources account for 81% of electricity generation at the end of this decade.
“This is a very ambitious scenario, which needs to be accompanied by a substantial increase in storage capacity for everything to work,” considers Marquina. To position ourselves as leaders on the continent, we have to expand our storage capacity.
Currently, excess generation that cannot be injected into the grid is lost. These “losses” could reach 7 TWh annually in Spain in 2030as calculated by Red Eléctrica. For that year, the sum of wind and photovoltaic production will exceed consumption during 20% of the hours of the day.
“Storage is a necessary protection for the business model of renewable assets,” says Marquina. Solar generation is the one that suffers the most instability. More photovoltaic energy is accumulated in the central hours of the dayinstead of from 7:00 p.m., when we return home and turn on the appliances, while the sun sets on the horizon.
Advancing renewable energy storage solutions not only provides flexibility to the electrical system, it also guarantees the supply and provides stability to the network. For all these reasons, promoting storage will be key to unlocking the real potential of renewable energies and of Spain as a future European hub.