Availability rate of the transmission grid

The quality of the transmission grid is also assessed on the basis of the availability of its facilities. Availability measures the capacity or possibility of use by the system of the various elements of the transmission grid, these being the electricity line circuits, transformers and active or reactive power control elements (reactors and capacitors). The availability rate is calculated as the difference between 100 and the non-availability rate of the transmission grid.

The following graphs show the evolution of the availability rate indicator over the last five years. The availability rate of the peninsular transmission grid in 2021 reached a value of 98.50 %, slightly lower than the rate of 98.57 % registered in 2020. In the Balearic Islands and the Canary Islands systems, the grid availability rate stood at 98.61 % (98.66 % in 2020) and 99.20 % (99.07 % in 2020) respectively. In general, 2021 showed an increase in the non-availability rate due to preventive and predictive maintenance carried out during the year, which contrasts with the decrease in scheduled non-availability of facilities as a result of improvement actions carried out on grid assets.

Annual evolution of the availability rate of the transmission grid