Availability rate of the transmission grid

The quality of the transmission grid is also evaluated based on the availability of the facilities making up the grid. Availability measures the capacity of the system to use the various elements of the transmission grid, these being the electricity line circuits, transformers, and active or reactive power control elements (reactances and capacitors).

The evolution of the availability indicator over the last five years is shown below. The grid availability index at a national level in 2025 amounted to 98.38%, higher than the 98.04% achieved in 2024. The peninsular transmission grid reached a value of 98.38% in 2025, higher than the 98.01% achieved in 2024. In the Islas Baleares and Islas Canarias systems, grid availability was 98.17% (98.54% in 2024) and 98.38% (98.63% in 2024), respectively. In all electricity systems, the grid availability index stands above the 97% reference value set out in Article 26.2 of Royal Decree 1955/2000. 

Annual evolution of the transmission grid availability index

Monthly evolution of the transmission grid availability index in 2025