As stated in the National Integrated Energy and Climate Plan (PNIEC), Tal com recull el Pla Nacional Integrat d’Energia i Clima (PNIEC), demand flexibility is a key tool for the electricity system, essential to integrate renewable energy, ensure supply security, and optimise grid use. Although regulation in Spain is not yet fully prepared to allow active demand participation in different grid services (such as primary and secondary regulation or voltage control), as is already the case in other European countries, there is a mechanism designed for demand flexibility that has been proving successful.

This is the Demand Response Service (SRAD), a mechanism regulated by Royal Decree-law 17/2022 and introduced in procedure P.O. 7.5 by Red Eléctrica de España. Since 2023, this tool has enabled demand to become an active resource to balance the electricity system in critical moments, serving as a last-resort mechanism for the grid.

An interesting aspect of this mechanism is that it provides both an availability payment and an activation payment. In the latest SRAD auction, for 2025, 1,148 MW were awarded (just over 50% of the system’s requirement, indicating that there is still significant room for new entrants), at a value of €246k/MW. There is also a payment for activations when they occur, although these are not frequent—since 2023, only four activations have taken place. As a result, in recent years, some consumers have been able to receive up to €246k/MW without substantially modifying their consumption.

Traditionally, this service was reserved for large consumers with a demand reduction capacity of at least 1 MW. However, thanks to recent reforms promoted by the CNMC, the door has now been opened to small consumers through aggregated participation. The proposed changes are currently under public consultation until September 11, 2025, although major modifications are not expected.

The main changes compared with previous auctions are:

  • Installations with a capacity equal to or below 1 MW may now be aggregated, provided they jointly reach the minimum of 1 MW required to participate.

  • Auctions will be held every six months (instead of annually), with more flexible preparation and adaptation timelines for participants.

  • Activation time has been reduced from 15 to 12.5 minutes, and the maximum activation duration reduced to 2 hours.

This regulatory change makes it possible for small and medium-sized enterprises, and even residential consumers, to join forces and act as a single entity in the electricity system. It represents a real opportunity to generate revenue and actively contribute to the energy transition. To do so, consumers must contact their electricity retailer, as these are currently the only entities able to provide this service in the grid.

In summary, SRAD represents a key tool for the resilience and stability of the electricity system. While it was traditionally reserved for large consumers, aggregation now allows smaller players to contribute and benefit as well. It is an opportunity to democratize flexibility and open the door to a more resilient and collaborative energy ecosystem, while reducing energy costs for consumers.

Mattia Barbero, PhD

Product Owner & Co-founder de Bamboo Energy