Spain moves to reinforce its power system with new mandates for BESS operators and more

Spain has published Royal Decree 997/2025 in the Official State Gazette (BOE) following its announcement earlier this week. The decree introduces urgent measures to improve the resilience, stability and responsiveness of the national electricity system after the 2025 incidents, formally recognising it as a “service essential to the general economic interest”.

Its main objectives include:

• Reinforcing voltage and frequency stability across the grid.
• Prioritising flexible capacity, including storage and hybridisation, and advancing demand electrification.
• Streamlining permitting and grid-access procedures for renewables and storage.
• Defining operational and remote-control requirements for large installations and battery energy storage systems (BESS).
• Setting quantitative storage-capacity targets for 2030.

The decree assigns new mandates to Red Eléctrica de España (REE) and the Comisión Nacional de los Mercados y la Competencia (CNMC) in response to the 28 April 2025 blackout. A key new ruling is they must inspect and analyse the operations of major generators and propose measures to reduce electricity costs and avoid future outages. According to REE, the “reinforced operation mode” since May has cost about €422 million.

Within six months, the CNMC must report on compliance with voltage-control obligations, a key cause of the blackout, by all relevant market participants. It can request data from utilities and assess their restoration capabilities. In the same period, the government will review balancing-service and technical-constraint regulations to reflect new system conditions under principles of technological neutrality and cost optimisation.

REE has three months to analyse stabilisation systems for synchronous and asynchronous generation to reduce oscillations, and six months to define minimum standards for oscillography and incident monitoring to ensure traceability and time synchronisation.

Storage outcomes

On storage, the decree provides a precise technical definition of installed power (“potencia instalada“) as the “lowest power rating among serially connected limiting elements (inverter, transformer, battery, etc.)” at both module and plant level. This removes ambiguity in authorization processes and unifies application criteria.

Hybrid storage projects also gain through significant simplifications. Battery modules within the boundary of an already approved project with a favourable Environmental Impact Statement are exempt from simplified environmental review and are now declared urgent and of public interest, which should halve administrative processing times under Royal Decree 1955/2000.

The definition of repotenciación (repowering) is expanded beyond the EU directive to include full or partial equipment replacement to improve efficiency, increase output or boost installed power. The government will present a national roadmap within nine months, outlining objectives, regulatory measures and monitoring mechanisms.

To deter speculation with grid-connection rights, consumers connected above 1 kV will lose their access permits if less than 50% of granted capacity is used within five years.

Measures to promote demand electrification include potential tax and municipal incentives for electrification projects, heat pumps, industrial charging and other electric loads. Industrial demand will be encouraged through dedicated tenders and reserved grid nodes prioritising new technical and industrial users.

The decree also supports innovation through authorizations for generation or storage platforms that are in R&D. Once granted, connecting new prototypes will require only an operational permit, provided approved technical and environmental conditions remain unchanged.

Finally, binding deadlines are set for new network extensions — from five days for low-voltage work with no construction up to 80 days for high-voltage projects. Where external companies perform the work, distributors must follow clear inspection and verification milestones.

From pv magazine Spain.