• The Almacena project, a pioneering initiative in Europe, represents an investment of over 3.5 million euros

• During 2014, this technology has stored and evacuated back into the electricity system the equivalent of the consumption used by 100,000 homes for over five hours

The Almacena project, in which Red Eléctrica de España has invested over 3.5 million euros, has successfully completed its first year in operation, in which the Company has performed daily 180 full charge-discharge cycles of this electrochemical energy storage system. The tests carried out during 2014 were performed by Red Eléctrica to evaluate the usefulness of these technologies.

With a power output of 1 megawatt (MW) and a capacity of 3 megawatt hours (MWh), this electrochemical storage system was installed in 2013 at the 220/400 kV Carmona substation in the province of Seville, and has a similar capacity to 600,000 typical smartphones batteries. With the Almacena project, Red Eléctrica has taken the first steps to technically validate the opportunities for improvement in security of supply and energy efficiency, taking on the commitment for greater integration of renewable generation into the system.

The storage system, which has been developed according to the specifications of Red Eléctrica, is located within a container 16 metres long containing 9,856 lithium-ion prismatic cells that are grouped into 704 modules and these, in turn, in 32 racks. Thanks to a control system designed specifically for Red Eléctrica, the system is ready to store energy in those times when it cannot be absorbed by the system due to lack of demand; i.e. allowing energy to be stored in the valley period of the demand curve (times of lower industrial activity and consumption, usually at night) for use depending on the needs of the system, at a later time.

During its first year in operation, the lithium-ion battery stored a total of 540 MWh, equivalent to the demand of 100,000 homes for more than five hours or a two-million kilometre journey for an electric vehicle. All the electricity stored in 2014 was returned to the electricity system without difficulties.

If we take into account that the Almacena project seeks to optimise the use of renewable generation on the Spanish Peninsula, more than 43% of the electricity stored in the lithium-ion battery came from renewable sources.

This R&D+i project was commissioned in December 2013 and its aims, amongst others, is to assess this technology for the optimised management of the demand curve, its capability to maintain grid stability and guarantee system functionality within the established technical voltage ranges.

This electrochemical storage system is located in the Carmona substation (Seville), one of the most complete facilities consisting of 220 and 400 kV switchyards and with a transformer capacity of 1,200 megavolt amperes (MVA). In addition, due to the firm commitment that this Andalusian municipality has towards energy efficiency and renewable energy development, Red Eléctrica identified this location as suitable for this electrochemical storage battery.

The main objective sought by Red Eléctrica with the Almacena project is the study, analysis and investigation of the behaviour of this type of storage systems and assess its possible implementation in the future.

The increased presence of renewable generation and its variable nature, along with the need to manage large differences between electricity demand in peak and valley periods and operate the system ensuring security and quality of supply, makes energy storage systems such as the Almacena project represent an effective mechanism to ensure the integration of renewable energies and improve the efficiency and sustainability of our energy model.

In 2013 and 2014, Red Eléctrica invested 22.5 million euros in technological innovation projects, such as the Almacena project whose aim is to study the feasibility of developing and implementing solutions that increase system efficiency and facilitate the integration of renewable energy.

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