Interruptions of national electricity grid go up drastically

ISLAMABAD: The duration and frequency of interruptions of the national electricity grid and its splitting increased drastically in 2016-17, showing a poor performance of the National Transmission and Dispatch Company (NTDC).

This has been reported by the National Electric Power Regulatory Authority (Nepra) in its Performance Evaluation Report 2016-17 on the NTDC released on Thursday. The report is based on the annual performance report submitted by the system operator itself under performance rules of 2005.

The regulator said the interruption was witnessed around 1.08 hours per point (one hour and 4.8 minutes) which showed an increase of 135 per cent as compared to preceding year’s 0.46 hours per point (27.6 minutes). System duration of interruption is a reliability indicator that measures the average outage duration that an interconnection point observes a year.

Regarding the system frequency of interruption, Nepra observed that average number of outages per circuit for the NTDC was 0.35 during the report period, showing an increase of 84.2pc over the previous year i.e. 0.19. System frequency of interruption is a reliability parameter that measures the average number of outages per circuit in a year.

Also, an increase of 1.89 times (89.6pc) had been observed in total number of outages over the previous year i.e. from 87 to 165. Moreover, the number of 132 kV outgoing circuits had also increased by 22 numbers to 476 as compared to 454 the preceding year.

The regulator said the NTDC reported to have not served 74.98 million electricity units of energy during the year which showed sub-par transmission system security. This meant the system operator lost about Rs415 million as measured by energy transportation charges.

The NTDC reported 165 incidents of loss of supply during 2016-17 which translated into total duration of 515 hours. Average duration per incident of energy not served was reported at three hours and seven minutes.

Nepra observed that system disturbances had increased from two to 10 times in 2016-17 as compared to the preceding year, indicating an alarming situation for NTDC’s network. The company has been directed to follow the day-to-day and long-term principles, standards, procedures and guidelines for planning, operation, dispatch and connection purposes for normal and abnormal transmission system conditions to avoid loss of supply to the consumers and hence financial loss to the national exchequer.

On the positive side, the data pertaining to the number of voltage violations as submitted by the NTDC showed 16.5pc improvement in 2016-17 as compared to the preceding year. During 2016-17, the number of voltage violations for the NTDC remained 104,924, indicating a 16.5pc reduction as compared to 125,233 violations in the preceding year.

During the reported period, the NTDC system frequency varied from 49.32 hertz to 50.72 hertz and violated the prescribed limits 35 times; however, it has shown improvement in comparison to the preceding year. The acceptable variation limit under performance standards is 49.5Hz-50.5Hz.