Energy storage

Batteries for large-scale energy storage

The modules with the batteries are placed in 6-meter long containers, similar to those used in maritime transport, which are located next to wind farms.

The lithium-ion batteries used for energy storage are very similar to those of electric vehicles and the mass production to meet the demand of electric mobility "is making their costs reduce a lot and their application viable to store large volumes of energy, which is known as stationary storage," explains Ana Ibáñez, Repsol Energy Storage Manager. This drop in costs is accelerating the implementation of this technology and in 2023 alone the installed capacity in the world almost doubled, according to the IEA.

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The reduction in the cost of lithium-ion batteries due to the promotion of the electric vehicle is helping their deployment as a large-scale storage solution

These infrastructures consist of a set of containers, such as those used in maritime transport, inside which the modules with the batteries and operating systems are installed. The containers are connected to the electricity grid through a transformer. It is, therefore, an easily scalable solution depending on the storage needs. The Spanish Wind Energy Association (AEE), which groups together this sector in Spain, states that the batteries, "taking into account their versatility and the fact that they can also be physically located at the facilities," are today the most suitable technological option for wind farms, thus opting for hybrid plants where renewable production and storage coexist.

In a short while, the containers have gone from measuring 40-feet long to 20 feet (6.10 meters), "thanks to the fact that the energy density, the amount of energy that we can put in the same container, has been greatly increased. Before, those of 40 feet had a capacity of 4 MWh and now up to 5 MWh is achieved in 20 feet," Ana Ibáñez states. For a year, Repsol has had a facility of this kind at its Jicarilla photovoltaic plant, in New Mexico (USA), which has 24 containers of 40 feet and a storage capacity of 80 MWh.

Battery storage infrastructures

6.10

meters

Average length of containers

MWh

Storage capacity of a container

+/-1,000

m²

Surface area that 15-16 containers occupy

Another advantage of these facilities is that they don't require large areas of land. "A facility of 15-16 containers, which is enough to assist a large photovoltaic plant of those existing in Spain," states Luis Marquina, of AEPIBAL, "would occupy no more than 1,000 m² and can be located next to the electrical substation, which is where it has the least impact on the environment because it is already an industrialized area." This technological alternative also has its challenges, such as those related to the circular economy and the improvement in the recycling of used batteries, or their dependence on scarce raw materials such as cobalt or lithium itself.

Baterías de almacenamiento en contenedores

China has surpassed the United States as the main global market for stationary battery storage and in 2023 it represented 55% of the new installed capacity. The EU is third and it is estimated that the European market could grow by up to 20% annually in the coming years. "The pending subject is that this technology be made in Europe, which today can't compete with the prices of Chinese manufacturers," Marquina notes.

In Spain, this sector is just starting and "there are only 5 MW installed, although a series of projects totaling 6.5 GW have already been granted grid access permission. If the decrease in costs continues and regulation promotes a market that makes these assets profitable, we could see a very significant inflow of projects in 2026-27," Marquina ensures. Something that represents an opportunity because "an ecosystem of renewable energies with the right storage could make us the European country with the most competitive electricity prices."