TRANSMISION

Energy not supplied (ENS) and average interruption time (AIT) of the transmission grid

Information based on provisional data from 8 April, 2022

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The service quality indicators for 2021 remain within the acceptable values set out in Royal Decree 1955/2000.

The key performance indicators of global quality according to Royal Decree 1955/2000 are Average Interruption Time (AIT) and Energy Not Supplied (ENS).

In the peninsular electricity system, 17 supply interruptions were registered in 2021, 42 % more than in 2020. This rise is reflected in the increase in the ENS compared to the previous year (188 MWh in 2021 compared to 95 MWh in 2020). Similarly, an AIT value of 0.41 minutes was recorded (0.21 minutes in 2020), despite this result, it is still well below the reference value of 15 minutes established in article 26.2 of Royal Decree 1955/2000. The main incident occurred at the 220 kV Dos Hermanas facility with an ENS of 81 MWh.

In the Balearic Islands electricity system, the continuity of supply indicators for 2021 also showed a clear improvement over the previous year. One supply interruption was recorded, resulting in an ENS of 1 MWh (4 MWh in 2020) and an AIT of 0.07 minutes (0.47 minutes in 2020). Something similar occurred in the Canary Islands’ electricity system, with an ENS of 33 MWh (corresponding to 4 supply interruptions) and an AIT of 2.33 minutes.