Batteries Take Over BOE: Nearly 930 MW of BESS Advance in Spain as 700 MW of Renewables Decline

Energy storage gained ground in the Official State Gazette (BOE) during October. In a market marked by renewable energy curtailment and episodes of zero or negative prices, developers accelerated the integration of batteries into photovoltaic and wind facilities to enhance their operational flexibility.

According to a review by Energía Estratégica, at least 928.81 MW of battery storage were included in files published during the month, although at various stages of the administrative process.

Of this volume, 566.55 MW obtained prior administrative authorizations (AAP), construction authorizations (AAC), or both, while another 362.26 MW appeared in public information or environmental assessment procedures.

This movement contrasted with the withdrawal of 699.92 MW of renewable energy, distributed among administrative dismissals and withdrawals by their developers. Added to this balance were 184.23 MW of wind power with unfavorable environmental impact statements in Galicia, a situation that requires differentiated treatment.

Tagus 2 leads the expansion of energy storage

The largest individual project was Tagus 2 HBESS, promoted by Khons Sun Power in Toledo. The facility obtained the prior administrative authorization (AAP) and the environmental assessment (AAC) to integrate 176.44 MW of batteries into a 224.4 MW photovoltaic plant.

The operation stood out for its scale: the BESS capacity equates to nearly 79% of the associated photovoltaic capacity, a proportion that reflects the growing weight of storage within hybrid configurations.

Ignis also advanced with two developments totaling 90.07 MW BESS. In Madrid, Almacenamiento Azor Solar received prior authorization to integrate 68.51 MW of batteries into a 64.02 MW photovoltaic plant. In Toledo, Mulhacén obtained the same permit to add 21.56 MW BESS to a 70 MW solar installation.

The applications represent different sizing strategies, from storage systems with lower power than the generating plant to configurations where the batteries exceed the nominal photovoltaic capacity.

In Castilla y León, Solaria obtained prior and construction permits for two nearly identical modules: Santiz I in Salamanca and Castor in Toledo. Each project includes a 19.99 MW BESS alongside a 49.99 MW solar PV plant, totaling 39.98 MW of new storage capacity.

Opdenergy standardizes its batteries in Aragon

The repetition of designs was one of the most visible patterns in October. Opdenergy obtained the preliminary and final environmental permits for three 26.74 MW BESS projects, each associated with existing solar facilities in Aragon.

Los Arcos and Montesol, in Teruel, and Los Belos, in Zaragoza, add up to 80.22 MW of authorized storage.

The company also appeared in the environmental procedure for the Plana de la Pena 1 and 2 developments in Zaragoza, with another 53.48 MW BESS, distributed across two 26.74 MW modules.

In total, the five systems represent 133.7 MW of batteries, although only 80.22 MW hold the energy authorizations noted in the review.

The repeated configuration allows for the identification of a standardization strategy that may facilitate the replication of engineering and equipment across facilities, although the files do not allow for quantifying investment or construction savings.

Aragon also concentrated Iberdrola’s efforts, which obtained the preliminary and final environmental permits to incorporate 27.64 MW BESS into its 42.56 MW Teruel photovoltaic plant.

Naturgy, Statkraft, and Enel expand the map of hybridization

In Andalusia, Naturgy secured the prior and construction permits for Tabernas I and II, two BESS systems of 19.8 MW each, associated with 48.8 MW solar photovoltaic plants in Almería.

The company also submitted Los Pedreros in Albacete for public consultation, a project that proposes incorporating 25.08 MW of batteries and a 0.4 MW flywheel to a 49.95 MW wind farm.

This combination introduces a technological variant within hybridization strategies by integrating electrochemical storage and an inertia system.

In Zamora, Statkraft submitted the Ribadelago Hybrid and Sanabria Hybrid projects for public consultation, featuring 69.65 MW BESS associated with 80.85 MW of solar photovoltaic capacity.

Meanwhile, Enel Green Power obtained the prior administrative permit (AAP) and the construction permit (AAC) for Tesouro Storage in A Coruña, which will incorporate 17.5 MW of batteries into a 50.4 MW wind farm.

The expansion also reached independent storage. In Castellón, Soner Picasso obtained the prior administrative permit for the 55.18 MW BESS Cuevas, with no associated renewable energy installation identified in the mapping.

The overall picture shows that the integration of batteries is no longer limited to solar parks: it extends to wind projects, hybrid configurations, and independent developments. Their profitability will depend on operational opportunities, available revenues, and investment costs, as well as the ability to shift energy to hours of higher value.

The BOE screening: nearly 700 MW rejected or abandoned

While energy storage advanced, October saw 265.2 MW rejected by the administration and 434.72 MW withdrawn through rescissions, without duplicating capacity shared across applications.

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Castilla y León accounted for the five identified rejections, which affected wind projects and photovoltaic hybridization modules.

In Soria, the administration rejected three solar developments associated with existing wind farms: Ventosa del Ducado, by Iberdrola, with 43.89 MW; Bordecorex Norte, by Biovent Energía, with 44.20 MW; and Los Campillos, also linked to Iberdrola, with 33.83 MW of photovoltaic capacity.

The three cases totaled 121.92 MW of additional solar capacity rejected, without this implying the removal of the original wind farms with which they were intended to be hybridized.

In León, Cefiro Holdco received rejection resolutions for El Páramo, with 92.4 MW, and Ampliación El Páramo, with 50.88 MW. Both facilities accumulated 143.28 MW of wind capacity.

Galicia presented another environmental front. The wind farms Alamoceiros, Chamarrapio, and Xubrintas, in Pontevedra, received unfavorable environmental impact statements. Their capacities, of 68.49 MW, 53.79 MW, and 61.95 MW, respectively, total 184.23 MW.

These latter files are not included in the count of rejections, as an unfavorable environmental declaration does not, in itself, equate to a rejection of the energy authorization.

Greenalia, Solaria, and Enel pull back more than 430 MW

Withdrawals displayed a different dynamic. In Galicia, Greenalia formalized the withdrawal of two wind projects: Mistral, at 106.4 MW, and Nordés, at 67.2 MW.

Both parks represented 173.6 MW of voluntarily withdrawn wind capacity.

In Zamora, Solaria withdrew from continuing with Valentina Solar, a 60.38 MW project, and the 90 MW Valentina wind park, which was planned to be hybridized with that photovoltaic facility.

The withdrawal of the complex thus affected 150.38 MW of solar and wind capacity, counting the photovoltaic plant listed in both files only once.

Enel Green Power was added to this list, withdrawing from FV El Clavel, a 110.74 MW photovoltaic plant in Albacete.

Although withdrawals may respond to technical, financial, or strategic reviews, the analyzed resolutions do not allow establishing a common motive for these developers' decisions.

The contrast is especially visible in Solaria and Enel, which during the same month registered administrative advances in storage and withdrawals from other renewable developments.

Toledo and the plateau are concentrating the pressure on the territory

The energy expansion was also reflected in the procedures for declaring public utility (DUP) and the prior minutes for land occupation.

Toledo gathered some of the main photovoltaic files, led by Ebisu II, promoted by Envatios, with a capacity of 164.84 MW, whose DUP project was submitted for public information.

The province also concentrated three public utility declarations granted to projects linked to EDP Renovables: Marcote, with 23.36 MW; Morata de Tajuña 3, with 42 MW; and Tobizar, with 22.8 MW. Together, they totaled 88.16 MW of photovoltaic capacity.

EDP also promoted the processing of Los Romeros and Los Callejones, two facilities of 62.7 MW each, with development between Toledo and Madrid. The package represents an additional 125.4 MW in public information for prior authorization and environmental assessment.

In Guadalajara, the BOE published actions related to the prior minutes for land occupation concerning Bichero Solar, Bruma Solar, Montería Solar, and Ojeador Solar, four projects that total 243.08 MW of photovoltaic capacity.

Procedural pressure extended to Madrid with Quilla Solar, at 51.04 MW, and Varadero Solar, at 47.71 MW, both linked to land occupation proceedings.

These procedures highlight the territorial scale of the renewable portfolio, though they must be distinguished from construction permits: a DUP or the lifting of preliminary records does not equate to the operational start of a facility.

October solidifies two speeds in the renewable portfolio

The BOE balance reveals a shift in development priorities. On one hand, 928.81 MW of BESS appeared in administrative proceedings, featuring large-scale projects and standardized modules that leverage existing renewable energy infrastructure.

On the other hand, 699.92 MW of renewable energy projects were dismissed or withdrawn, while another 184.23 MW of wind projects received unfavorable environmental declarations.

This difference does not imply that batteries are directly replacing renewable energy plants, but rather that the ability to manage when electricity is delivered is gaining greater importance for new investment models.