Energy storage is one of the pillars of the transition towards a sustainable energy model, by giving the necessary flexibility to the electricity system to support the growth of renewable energy generation and contributing to the efficient management of electricity networks.
The newspaper Cinco Días has listed reflections on this topic by Enertis Applus+, which has more than 15 years of experience in this sector.
The growth of renewable energy continues unabated, driven mainly by its high competitiveness. But the intermittent nature of non-manageable sources, mainly solar and wind energy due to their widespread rollout, represents a challenge. It is essential to integrate energy storage solutions that ensure the availability of generation capacity at all times, as well as maintaining the stability and flexibility of the network which are necessary in managing peaks in capacity and energy demand. Deploying it will increase Spain's energy sovereignty, which will protect the Spanish economy from the volatility of the international markets for fossil fuels, thus reinforcing the security of supply and bringing us closer to the goal of climate neutrality.
Spain is in a critical phase in making use of renewable energy. Access points and connections to the grid are being enabled for many photovoltaic projects under development whose Capacity Utilisation Factor (CUF) - the percentage of energy put into the grid with respect to the maximum amount they could put in if they were producing at the maximum level under optimal conditions every minute of the day - don't even reach 20%. The production of a photovoltaic plant is not consistent throughout the year, it depends on the level of sunshine, so incorporating systems that store energy would increase the value of the CUF and make the most of these limited points.
“Legislation has already made steps forward in this regard, allowing for the hybridisation of different technologies in the same project. Within the framework of the technical-economic feasibility analysis that we put forward for this type of project, we have carried out case studies in which, by hybridising wind, solar and batteries, we have exceeded CUF levels of 50%," explains Santos García, general director of Enertis Applus+.
At present in Spain, batteries are a technology whose viability still has a long way to go in projects applied to the energy balance for the injection of power into the electrical grid during peak hours. Currently, lithium-ion batteries dominate the market for a wide range of uses - such as electric vehicles - and are the most suitable solution for energy storage for periods of less than four hours; while redox flow technologies, suitable for storage for longer periods, are key to the integration of renewables and to providing different services to the network. Other systems that can be considered storage, such as green hydrogen, are beginning to take firm steps forwards along the path towards commercial development.
What Spain needs is a clear regulatory framework that gives certainty on the possible injection that batteries can receive for the services they provide, an open issue and a fundamental matter for investors in order to have an adequate price signal and an expectation of reasonable cost recovery and, in turn, to drive storage deployment.