Red Eléctrica de España (REE) has identified 78 transmission grid nodes where demand access capacity auctions will be activated. Of these critical points, 46 correspond to 220 kV networks and 32 to 400 kV networks, depending on their nominal voltage level.
A regional analysis shows Andalusia as the autonomous community with the highest concentration, accounting for 19 affected nodes. It is followed by Castile and León (11), Aragon (10) and Castilla-La Mancha (9), while the Community of Madrid and Extremadura register seven nodes each. Catalonia (5) and Galicia (4) also appear on the list, while the Basque Country, Valencia and Murcia each have two nodes.
The publication, dated 15 December 2025, is issued pursuant to Articles 20 bis and 20 quater of Real Decreto 1183/2020, which regulates access to and connection with Spain’s electricity transmission and distribution networks.
Under these provisions, when multiple access requests converge at the same node, and technical capacity is insufficient to meet them simultaneously, a competitive auction process must be launched to allocate the available capacity in an objective and transparent manner. The public identification of these nodes represents a key step in the technical and regulatory organisation of the power system amid growing pressure from new electricity-intensive demand.
The measure not only pinpoints where the grid is under the greatest strain, but also sends a clear signal to industrial developers, logistics operators and promoters of electric mobility, green hydrogen and energy storage projects about where they should prepare to compete for capacity.
This announcement comes in the context of structural grid stress, particularly at the distribution level. Capacity maps published by distribution companies under Circular 1/2024 of the CNMC indicate that 83.4% of distribution nodes are already saturated, meaning there is no technical margin to accommodate additional demand without further network investment.
According to Energía Estratégica, this situation has generated concern among renewable energy and industrial electrification stakeholders. Market experts are calling for urgent measures to increase flexibility and accelerate investment in power grids, enabling the integration of new demand and innovative technologies.
In this context, energy specialist Abelrado Reinoso highlighted the need to enable available positions at substations, allow shared use between demand and generation, introduce more flexible access criteria, and prioritise projects with higher technical and financial maturity. He also pointed out that mechanisms such as flexible access, recently introduced under Circular 1/2024, could provide solutions if properly implemented:
“The key is understanding that not all capacity is needed 24/7, and that the system must be able to value that,” he explained.
The document published by REE specifies that it “shows the transmission grid nodes where the System Operator has confirmed that the conditions exist to hold a demand access auction,” detailing the notification date, voltage level and geographic location of each node.
For the energy sector, this updated map is not merely a technical disclosure. It can function as a strategic guide for decisions related to plant siting, power purchase agreements (PPAs), electricity efficiency investments and industrial project development. At the same time, it allows stakeholders to anticipate regulatory competition for access to a constrained grid, with direct implications for project timelines and overall investment viability.
