New Zealand Gazette – 1998 – No. 193

Page 4564

✨ Reliability Performance Measures



4564 NEW ZEALAND GAZETTE No. 193

TRANSPOWER NEW ZEALAND LIMITED GROUP

Part V
Reliability Performance Measures To Be Disclosed By Trans Power
(Disclosure Under Regulation 17)

  1. Total number of unplanned interruptions*
    Resulting from 58 loss of supply incidents in 1997-98

  2. Electricity customer interruptions in system minutes**
    planned
    unplanned

  3. Underlying electricity customer interruptions in system minutes**
    Underlying interruptions are those interruptions of 1 system minute or less duration
    planned
    unplanned

  4. Average supply reliability ...............%
    Measured by the energy supplied divided by the sum of the energy supplied and not supplied

  5. Uneconomic generation due to planned and unplanned transmission system unavailability ...............%
    Uneconomic generation relates to the amount of electricity generated from any source other than the most economic source.

  6. Uneconomic generation due to HVDC system unavailability ...............%

  7. Uneconomic generation due to unplanned transmission system unavailability ...............%

  8. Planned interruption restoration performance ...............%

  9. Unplanned interruption response............%

1997-98 1996-97 1995-96 1994-95
103 164 229 184
5.1 13.6 12.2 19.5
2.1 2.1 5.8 4.4
2.9 11.5 6.4 15.1
5.1 6.9 7.1 14.1
2.1 2.1 3.1 2.9
2.9 4.8 4.0 11.2
99.9985 99.9959 99.9963 99.9942
0.02 0.55 0.81 0.68
0.01 0.47 0.73 0.60
0.01 0.12 0.22 0.15
90.5 72 80.5 92.5
98.1 100 99.1 100

The information compiled using estimated information includes Part V sections 2,3,4,5,6 and 7. The methodology used to calculate the estimated information is documented and available from Trans Power upon request.

The 1997/98 figures for uneconomic generation are considerably different than in previous years. The data for these figures has been collected in line with the specified guidelines. However, uneconomic generation is not relevant in the market environment as scheduling is carried out differently and ‘offers to generate’ are make after taking constraints into account and it is not possible to predict what the generator would have offered if the constraint was not present.

  • Where two supply voltages, or two customers, at the same station are both interrupted this is counted as two interruptions.

** The difference between the total and the sum of planned and unplanned is due to rounding.



Next Page →

PDF embedding disabled (Crown copyright)

View this page online at:


VUW Te Waharoa — PDF NZ Gazette 1998, No 193


NZLII — PDF NZ Gazette 1998, No 193




✨ LLM interpretation of page content

🏭 Transpower New Zealand Limited Reliability Performance Measures (continued from previous page)

🏭 Trade, Customs & Industry
Reliability Performance, Electricity, Interruptions, Supply Reliability, Uneconomic Generation, Transmission System, HVDC System, Performance Metrics, Electricity Industry