The publication of firm demand capacity maps confirms that 83.4% of nodes are saturated and shows 0 MW available in key substations, constraining new industry, renewables and green hydrogen. The sector is calling for flexible connections and investment in networks with clear rules from CNMC and MITECO.
For the first time, Spain has made transparent the firm demand access capacity at each distribution node, as required by CNMC Circular 1/2024 and its 2025 resolutions on formats and detailed specifications.
The picture is stark: 83.4% of nodes are saturated, preventing the connection of new demand across much of the country. Requests at nodes with “0 MW” are inadmissible under RD 1183/2020, raising the risk of losing guarantees.
Most affected regions (highest node saturation)
| Autonomous Community | % of saturated nodes |
|---|---|
| Cantabria | 100% |
| Basque Country | 99% |
| La Rioja | 99% |
| Aragon | 96% |
| Navarre | 94% |
| Andalusia | 92% |
| Catalonia | 90% |
Least affected regions (lowest node saturation)
| Autonomous Community | % of saturated nodes |
|---|---|
| Galicia | 51% |
| Balearic Islands | 39% |
| Canary Islands | 35% |
| Asturias | 29% |
This scenario has been anticipated by AELEC for months, with reports showing a tenfold increase in requests over the last three years, of which only 10% could be met due to lack of capacity, leaving more than 60 GW pending.
“The medium-voltage grid collapse has become the main barrier to industrial development in Spain. The CNMC proposes an insufficient financial rate and a remuneration methodology that adds uncertainty. The distributors propose a scheme that effectively blocks flexible connection, when we all know it is the only way to free up capacity in the short term,” said Joaquín Coronado Galdos, Chairman of Build to Zero.
Flexible connection emerges as an immediate lever to release capacity in medium-voltage networks which, although saturated at peak times, operate many hours with spare capacity.
Circular 1/2024 already provides monthly visibility of saturation levels, and the CNMC Specifications (08/06/2025) define minimum and maximum power by voltage level and the calculation methodology for bars above 1 kV, a key requirement for planning investments.
At the territorial level, distributors’ maps show nodes with 0 MW or with high occupation in Andalusia, the Basque Country, Asturias or Galicia, affecting industry, data centres and electrification. Automatic inadmissibility at 0 MW nodes limits business planning until reinforcements or flexible management are in place.
In this context, Spain DC —the association that brings together the main data centre operators— warns that the lack of capacity in distribution nodes poses a threat to the deployment of new strategic digital infrastructures.
The entity calls for a more ambitious framework for network investment and agile connection mechanisms to enable the growing demand of the digital economy to be compatible with energy transition objectives.
Renewables, storage and green hydrogen: untapped potential
In parallel, saturation is compromising the integration of renewables and flexibility assets. “Spain has a unique opportunity in its renewable resources to guarantee strategic autonomy, strengthen its economic model, improve competitiveness and advance reindustrialisation. However, we are not taking advantage of this to attract investment and consolidate our industry,” said Alejandro Labanda, spokesperson for Spain Verde y Conectada.
The Alliance’s statement emphasises the lack of grid capacity and that the CNMC’s 2026-2031 regulatory proposals do not support grid development. This combination (physical bottlenecks and an unambitious regulatory framework) is, indirectly, what explains the lost opportunity for the country.
To this end, the entity drew up a position paper a few months ago proposing a realistic roadmap to make Spain a leading industrial reference in Europe, boosting our economy and strategic autonomy.
In this scenario, self-consumption and energy communities appear as still underutilised solutions. “They are a key part of the solution: they generate clean energy in the same place where it is consumed, reducing pressure on the grid and providing savings and energy security to households and businesses,” said José Carlos Díaz Lacaci, CEO of SotySolar.
A distributed model, complemented by behind-the-meter storage and demand management, could postpone reinforcement investments, accelerate electrification and improve supply quality, although it is not yet fully exploited.
For green hydrogen and electrolysers, closing the gaps in medium and high voltage and firm capacity are crucial. The CNMC regulations of 2025 standardise formats and parameters; however, without economic signals that enable network investment and flexible connection, many projects will not reach final investment decision within competitive European timelines.
What triggers the bottleneck (and how to unblock it)
Circular 1/2024 structures the process and provides visibility of saturation; RD 1183/2020 defines inadmissibility at 0 MW; CNMC’s 2025 resolutions establish method and formats. The next step is to align remuneration and financial rates with the network investment cycle, accelerating capacity and digitalisation for flexible operation.
At this point, all eyes turn to the CNMC. Last July, the body submitted to public consultation a new remuneration model for the 2026-2031 period of 6.46%, higher than the current 5.58% but well below the sector’s expectations, which placed the ideal figure at around 7.5%.
The proposal reduces allowable operating costs and is considered the lowest among peer European countries (Italy, the UK, Sweden or Ireland apply rates between 7% and 8.1%), raises the perceived risk for investment and limits the maximum investment cost for connecting new consumers and industrial projects.
According to the sector, these conditions discourage the necessary investments in electricity networks and cast doubt on the more than €53 billion planned up to 2030 to modernise and reinforce the national electricity infrastructure.
From now on, distributors will publish maps with monthly updates, node by node and by voltage level; thus, flexible connection —under limits of hours and power and with agreed curtailment— could free up MW where occupation is not simultaneous.
With 83.4% saturation, electro-intensive sectors, data centres and gigafactories remain on hold except in nodes with margin or on-site solutions (solar PV + storage). Demand response mechanisms, batteries and on-site PPAs can accelerate the arrival of projects while grid reinforcements progress.
