Today Red Eléctrica, in its role as system operator (SO), is publishing for the first time the access capacities for connecting demand at transmission grid nodes. These capacities have been calculated according to the technical criteria set out in the detailed specifications approved by the CNMC in its Resolution of 1 December. 

These technical calculation criteria, similar to those applied to generation, are designed to continue ensuring the safety and proper functioning of the system.

On the transmission grid alone, access and connection permits have been granted for 129 GW of wind and solar installations, 16 GW of storage facilities, and 19 GW of demand facilities. Of the latter, since 2022, when the current planning was approved, 11.8 GW of capacity has been granted for new demand, none of which is yet in service. Holders have five years from the date the permit was granted to connect. The volume of permitted demand pending connection on the transmission grid alone would represent a 25% increase over the country’s current demand. 

The published figures show that the transmission grid still has capacity for new demand at 25% of its nodes. This capacity can be allocated either through the standard priority criterion or via competitive tender.

The information published today fulfils the agreement reached by the CNMC on 13 February, following the System Operator’s reporting on both the calculation of access capacities and progress in agreeing on reference values. This information, which will be updated monthly, applies to all demand access capacity evaluations for the transmission grid. It will be revised as progress is made on reference values and as developments occur in the regulations concerning robustness requirements, as indicated by the CNMC in that agreement.

Robustness requirements

The results of the studies conducted, particularly those related to the dynamic criterion, confirm the need to ensure robustness requirements (voltage dip support) in future demand facilities that come into service, especially those connected through power electronics. 

The upcoming regulatory updates are expected to significantly increase the capacity that can be granted at many nodes where the current value is limited by the dynamic criterion, since the transmission grid could safely accommodate the additional flows required to supply new demand.

Agreements reached on reference values

For the first time, the detailed specifications define the capacity value reserved in the transmission grid for allocation to facilities connecting to distribution networks (reference values). Over recent months, the SO and distribution network operators have been working on this issue at nodes with interfaces between the two grids. These agreements must be formalised following the CNMC’s guidelines. 

The sum of values proposed by distribution network operators exceeds twice the system’s historical peak (45 GW). To date, agreements have been reached on 45% of the interfaces between the transmission grid and the distribution network, totalling 33.1 GW of capacity. 

To continue advancing in the process of agreeing on reference values, a significant number of cases have been identified that require additional regulatory criteria to ensure a consistent approach across all interfaces between the transmission grid and the distribution network. 

A continuing exercise in transparency

This publication marks a major milestone in terms of transparency, providing visibility into highly relevant information—such as substations with dedicated positions for demand, nodes where capacity will be allocated via competitive tenders, areas with shared capacity across different substations, access capacity values and available margins by criterion, as well as details on demand permits already granted for connection to the transmission grid and reference values reserved for the distribution network from the transmission grid at each node.
 

Check the access capacities (only in spanish)Conoce la capacidad de acceso | Red Eléctrica