20 MW BESS Battery in Salamanca: the new accelerated framework for solar hybridizations

Key data

Promoters of photovoltaic plants with the capacity to hybridize storage now have a faster administrative path without environmental assessment. The Resolution of September 16, 2026, published in the BOE on October 20, authorizes the «Solaria-Santiz I» BESS module of 19,993 MW for Planta FV100, SL in Valdelosa (Salamanca), hybridized with the existing photovoltaic installation «FV Solaria-Santiz I» of 49,989 MW. The key lies in the framework that makes it possible: the RD 997/2025 urgent measures, which changes the rules of the game for this type of projects.

What does this regulation establish?

The General Directorate of Energy Policy and Mines grants Planta FV100, SL two simultaneous authorizations: the prior administrative authorization and the administrative construction authorization of the «Solaria-Santiz I» BESS module. Both are granted in a single administrative act, which illustrates the streamlining introduced by RD 997/2025.

The technical and administrative elements of the project are as follows:

RD 997/2025 introduces two structural measures that make this accelerated processing possible: the exemption from environmental impact assessment for storage hybridizations with existing renewables, and the reduction of administrative timelines throughout the authorization procedure. Before this royal decree, similar projects required going through the ordinary environmental procedure, with the time and costs that entails.

Economic and operational impact

For renewable plant promoters, the impact of this new framework is twofold: reduction in processing costs and acceleration of time to operation. The exemption from environmental assessment eliminates one of the most costly and prolonged bottlenecks in the energy project development cycle in Spain.

From an operational perspective, BESS hybridization with an existing photovoltaic plant allows:

• Taking advantage of already-built evacuation infrastructure (in this case, the connection to the Santiz 220 kV REE substation), reducing investment in new network.
• Optimizing the already-granted connection point, without needing to request new network access.
• Improving the generation curve and dispatch capacity of the plant, increasing its value in the electricity market.
• Meeting the firmness and manageability requirements that the national electrical system demands from large-scale renewable installations.

The only additional investment in network infrastructure required by this project is the expansion of sectioning centers at 30 kV, which represents a marginal cost compared to the alternative of building a new evacuation line.

Who does it affect?

• Promoters of existing photovoltaic plants who want to add BESS storage to their installation.
• Energy storage companies that develop hybridization projects with renewables in Spain.
• Investors and infrastructure funds with assets in the Spanish renewable sector that evaluate the feasibility of adding batteries.
• Legal and technical advisors who process energy authorizations before the General Directorate of Energy Policy and Mines.
• Competent administrations (regional and local) in the consultation and reporting procedure for electrical installations.
• Network managers (REE and distributors) who must coordinate the connection of new storage modules to existing infrastructure.

Practical example

A promoting company has a 50 MW photovoltaic plant in operation in Castilla y León, with a connection point to a REE substation at 220 kV. It wants to add a BESS module of approximately 20 MW to improve its dispatch and access system adjustment services.

Before RD 997/2025, this project would have required initiating an ordinary environmental assessment procedure, with an estimated timeline of between 18 and 36 additional months and significant environmental processing costs.

With the new framework, following the precedent of the «Solaria-Santiz I» project by Planta FV100, SL:

• The hybridization is exempt from environmental assessment.
• Administrative timelines are substantially reduced.
• Evacuation can be carried out through existing infrastructure, without a new line.
• The only network works necessary are the expansions of sectioning centers (in this case, at 30 kV).
• Municipal reports and IGN are the main consultation procedures, and in the case of Valdelosa they were favorable without regional opposition.

The result: a project that previously could take 4-5 years to obtain all authorizations can now be processed in a notably shorter timeframe, improving asset profitability.

What should companies do now?

1. Review the portfolio of existing renewable plants to identify photovoltaic installations that are candidates for BESS hybridization, prioritizing those with connection points to already-operational high-voltage substations.
2. Analyze the applicability of RD 997/2025 to each specific project, verifying that the hybridization meets the requirements to benefit from the environmental assessment exemption and timeline reduction.
3. Contact the General Directorate of Energy Policy and Mines to initiate the prior administrative authorization and construction authorization procedure jointly, as has been processed in the «Solaria-Santiz I» case.
4. Coordinate with REE or the corresponding distributor the necessary expansions in sectioning centers (in this project, at 30 kV) to integrate the BESS module into the existing evacuation infrastructure.
5. Prepare documentation for consultation reports before the town council of the affected municipality and the National Geographic Institute (IGN), which are the bodies whose favorable report was decisive in this case.
6. Evaluate the impact on market strategy: the addition of storage allows access to system adjustment services and improves plant manageability, which can translate into additional income.

Official source

Consult complete regulation in official source

Notice: This article is for informational purposes only and does not constitute legal advice. For specific decisions, consult a qualified professional. Source: https://www.boe.es/diario_boe/txt.php?id=BOE-A-2026-21855