Service quality and unsupplied energy

The events that resulted in user power failures can be traced to accidents and failures not related to the procurement of dispatching resources.

Please refer to the “2010 Annual report” published on the Terna website in the section “Electrical system/Transmission service quality” for further details.

Finally, below are the reference indexes for the “quality of service and conduct of Terna NTG plants” pursuant to AEEG Resolution no. 250/04 and the Terna Network Code, which, in 2011, were above or in any case comparable with their respective targets.

  • AIT (Average Interrupt Time attributable to Terna) = 0.49 min/year with target = 1.00 min/year;
  • SAIFI + MAIFI (System and Momentary Average Interruption Frequency indexes per user directly connected to the Terna NTG, attributable to Terna) = 0.14; target = 0.22;
  • ENS (Energy not supplied attributable to Terna) = 306 MWh; target = 550 MWh;
  • ASA (Average System Availability of Terna network elements) = 99.32%; target = 99.05%.