Section 51 in Central Electricity Regulatory Commission (Terms and Conditions of Tariff) Regulations, 2019
51. Normative Annual Transmission System Availability Factor (NATAF).
(a)For recovery of Annual Fixed Cost, NATAF shall be as under:(1)AC system: 98.00%;(2)HVDC bi-pole links 95.00% and HVDC back-to-back stations: 95.00%:Provided that the normative annual transmission availability factor of the HVDC bi-pole links shall be 85%for first twelve months from the date of commercial operation.(b)For Incentive, NATAF shall be as under:(1)AC system: 98.50%;(2)HVDC bi-pole links and HVDC back-to-back Stations: 97.50%:Provided that no Incentive shall be payable for availability beyond 99.75%:Provided further that for AC system, actual outage hours shall be considered for computation of availability upto two trippings per year. After two trippings in a year, for every tripping, additional 12 hours outage shall be considered in addition to the actual outage hours:Provided also that in case of outage of a transmission element affecting evacuation of power from a generating station, outage hours shall be multiplied by a factor of 2.
