The Greek group Mytilineos has started the procedures to install an energy store in Salas using lithium-ion batteries. This project, designed by the Asturian engineering company Isastur, foresees an investment of 20 million euros and is the latest of a dozen initiatives already under way in the Principality to support the strong wind expansion planned. With the closure of coal-fired power plants, and pending the development of green hydrogen, it will be necessary to have facilities that are capable of storing energy at times of excess renewable generation to incorporate it into the electricity grid when there are peaks of demand or when the conditions for generation with clean sources do not exist because there is no wind or there is a shortage of water. Asturias, with a strong demand for electricity from the industry, needs to accumulate energy, put batteries to solve the intermittency of renewables.
“The development of energy storage is going to be one of the key tools to grant flexibility to the electrical system in order to support the significant growth of renewable generation, as well as contribute to the management of electrical networks,” says Belarmina Díaz, general director of Energy, Mining and Reactivation of the Principality, which adds that “great interest is being seen on the part of companies in the development of this type of project that is reflected in the deposit of guarantees that are made as a step prior to the request for access and connection to the transmission or distribution networks of electrical energy.
Different private promoters have already presented up to 18 energy storage projects valued at more than 7,550 million euros at the Principality Government’s European Projects Office –where initiatives that will be eligible for EU funds are compiled. A part of these projects are engineering proposals, such as the Asturian TSK, to transform the coal-fired power plants in Asturias into energy stores, but for the moment most do not have the support of the energy companies that own the power plants.
“Green battery of Asturias”.
Only EDP has taken a step forward to convert the Soto de Ribera coal-fired power plant – still operational – into the region’s great energy store. There, it plans to test up to four systems: lithium-ion batteries (an already mature technology that will also be adopted by the Mytilineos project in Salas), molten salt storage (electrical energy is accumulated in the form of internal energy from a fluid, to be later recovered in a steam turbine), liquid air storage (energy is accumulated by compressing and cooling air to a liquid state, which allows large amounts of air and therefore energy to be stored in a small space, and then recovered following the process reverse) and a hybridization system with redox flow batteries and reused electric vehicle batteries.
Reversible pumping stations.
EDP has publicly presented its “Batería verde de Asturias” project –which is complemented by hydrogen generation facilities and hydroscrew power plants–, but has not yet started processing it. Yes, ten energy storage projects have done so through reversible hydraulic pumping stations in western Asturias. Seven of these projects, promoted by EDP itself, Endesa, Magtel and Desarrollos de Valdetesinos, intend to take advantage of the existing reservoirs of Grandas de Salime, Doiras, Armón and La Barca. Near them, at a higher level, would be built large reservoirs linked to the swamps by transfer pipes. In off-peak hours, when energy is cheaper, water will be pumped to the upper tank; and at peak hours, when there is more electricity demand and the price of energy is higher –or when the electrical system requires it to cover the intermittencies of wind or solar energy– the water will fall by gravity and it will be turbined in reversible hydraulic power stations. The business groups Lamelas Viloria and Ingesanc are also processing another three reversible pumping plants but with mine water. Circuits will be located in the old farms of Buseiro (between the councils of Tineo and Cangas del Narcea), Coto Cortés (Degaña) and Cerredo, which will allow the storage of energy with the transfer of water between tanks.
Self-consumption and distribution.
In addition to large projects, there are also micro energy storage initiatives in the region, especially batteries linked to solar installations. “There is a deployment of small storage linked to self-consumption, which has exhausted the budget of the calls managed by the Ministry of Industry, and the distributors are also proposing storage projects that facilitate the management and operation of their networks,” says Belarmina García.