Electrical grid
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What is electricity grid capacity?
The capacity of the electricity grid is the 'maximum occupancy' of the electrical infrastructure. In other words, it represents the amount of energy that it can transport and distribute without compromising the technical safety of the system.
Just like in a stadium or on a motorway, there is a limit beyond which it is not possible to admit more electricity 'traffic'.
This capacity is defined by the design of the lines, transformers, substations, and protection systems that allow electricity to flow safely.
When that limit is reached, the electricity system operator must deny new access requests, even if there are projects ready to connect.
What are connection nodes?
A connection node is a point on the electricity grid to which industries, homes, or renewable energy plants connect to receive or feed in electricity.
If that node is full, it is not possible to accept more connections until it is reinforced or capacity is freed up.
For example, Endesa has 1,840 nodes in its distribution grid. These nodes act as 'gateways' to the electricity system.
However, the majority are at their capacity limit. In fact, 88% of Endesa's nodes cannot accept new connections.
The situation is widespread across the entire grid, as can be seen in the capacity maps published by Aelec (Association of Electric Energy Companies) in September 2025. These maps uniformly collect information on each node with a voltage above 1 kV: its location, the available, occupied, or pending capacity, as well as the possibilities for reinforcement.
This information represents a transparency milestone, as it helps consumers, developers, and industries identify where capacity exists before requesting a connection.
And the conclusion from these maps is clear: 83.4% of the distribution grid nodes in Spain are saturated.
Is the electricity grid in Spain saturated?
Yes. There is a widespread saturation problem across much of the country.
Since 2023, requests for grid access have multiplied. In 2024, around 67 GW of new demand was requested, but almost half was rejected.
Endesa's case illustrates this situation well: in 2024 and the first half of 2025, it received requests for 38 GW, a figure that doubles the peak demand of its entire national distribution grid, which stands at around 18 GW.
The scale of the problem is better understood when considering the industrial investments associated with these rejected requests. According to Aelec, connection requests from the industrial sector alone that could not be met were linked to €60 billion of investments that did not materialise
In this context, saturation is not just a technical problem: it is a direct brake on economic development, the electrification of industry, and the achievement of climate goals.
Is this saturation something new in Spain? Unfortunately not, because it was already experienced during the boom in connection requests for new renewable generation to the grid. The fact that it is now happening with demand requests—those from consumers—is a result of the energy transition's natural progression towards greater electrification of the economy based on clean generation sources.
How can the lack of capacity be solved?
Invest more in grids
The first answer is to invest in the expansion and digitalisation of the grids.
Endesa has announced a €4 billion plan for the 2025-2027 period, a 45% increase on the previous plan.
However, the regulatory framework does not encourage these investments. The CNMC has proposed a remuneration model for 2026-2031 that, according to the industry association, introduces high risks and sets an insufficient rate of return (below the 7.5%-8.5% applied in other regulated sectors in Spain, such as airports or telecommunications, or in other neighbouring countries).
In the sector's own words, without adequate incentives and legal certainty, the necessary investments could stall, with a direct impact on electrification and Spain's competitiveness.
Free up blocked capacity
Another path is to free up capacity reserved for projects that never materialise.
There are nodes with capacity committed to initiatives that have no deadline and have made no progress in their administrative processing. This creates a 'bottleneck' effect that prevents mature and viable projects from connecting.
The solution involves demanding financial guarantees and strict deadlines, as well as eliminating duplicate applications.
However, this is a partial and slow solution, as it requires regulatory changes and does not solve the root of the problem: the lack of new capacity.
Streamline permits and procedures
In Spain, commissioning a medium-sized infrastructure project takes over seven years, with most of that time spent on administrative paperwork and authorisation processes.
The country's electrification demands that these timelines be shortened, permits simplified, and the various administrations involved coordinated.
The data is stark: more than 80% of distribution nodes are saturated. The grid cannot absorb the rate of growth that electrification requires.
The future depends on investing in new infrastructure, freeing up blocked capacity, and streamlining project processing. But above all, it depends on having a stable and attractive regulatory framework for investment.
This means that connecting new industries, servicing new homes, enabling energy storage projects, or deploying charging points for electric vehicles depends directly on the grid's capacity.
If Spain succeeds in reinforcing its electrical infrastructure, it will be in a position to attract investment, accelerate electrification, and meet its climate commitments.
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