3516

NEW ZEALAND GAZETTE, No. 134

30 NOVEMBER 2007

The Electricity Information Disclosure Requirements¹

(For 12 months ending 30 June 2007, 2006, 2005, 2004)

Part 4

Energy Delivery Efficiency Performance Measures and Statistics

(Disclosure under Requirement 20)

1. Energy delivery efficiency performance measures

(a) Load factor (%)

Electrical energy entering the transmission system as percentage of maximum demand times hours per year

65.60 66.50 69.70 71.05

(b) Loss ratio (%)

Transmission losses as percentage of energy entering the system

3.74 3.63 3.76 3.82

(c) Capacity utilisation (%)

Maximum demand as percentage of total transformer capacity

Based on Maximum Continuous Ratings

50.37 51.61 49.72 45.17

2. Statistics

(a) System length, broken down by voltage (km)

Total ᵃ 17,334 17,245 17,045 17,041

350 kV (HVDC) 611 611 611 611

270 kV (HVDC) 611 611 611 611

0 kV (HVDC earth electrode) 31 31 31 31

220 kV (HVAC) 8,617 8,611 8,380 8,376

110 kV (HVAC) 6,299 6,219 6,073 6,073

66/50/33/11 kV (HVAC) ᵇ 1,165 1,165 1,339 1,339

(b) Circuit length of overhead electric lines, broken down by voltage (km).

Total ᵃ 17,249 17,163 15,960 16,966

350 kV (HVDC) 571 571 571 571

270 kV (HVDC) 571 571 571 571

0 kV (HVDC earth electrode) 31 31 31 31

220 kV (HVAC) 8,617 8,611 8,380 8,376

110 kV (HVAC) 6,294 6,214 6,058 6,066

66/50/33/11 kV (HVAC) ᵇ 1,165 1,165 1,339 1,339

NB: HVDC link submarine power cables measure approximately 80km. Broken down by voltage:

350 kV (HVDC) 40 40 40 40

270 kV (HVDC) 40 40 40 40

(c) Total circuit length of underground electric lines (km)

( 110 kV HVAC) 5 5 5 5

(d) Transformer capacity (Maximum Continuous Ratings) (kVA) 13.31x10⁶ 12.88x10⁶ 12.75x10⁶ 12.65x10⁶

(e) Maximum demand (kilowatts) ᶜ (kW) 6.71x10⁶ 6.65x10⁶ 6.54 x10⁶ 6.09x10⁶

(f) Total electricity entering the system (before losses) ᶜ (kWh) 39.13x10⁹ 38.72x10⁹ 38.71x10⁹ 36.02x10⁹

(g) Total amount of electricity (in kilowatt hours) supplied from the system (after losses of electricity) during the financial year on behalf of each person that is an electricity generator or an electricity retailer, or both: ᶜᵈ (kWh) 37.66x10⁹ 37.33x10⁹ 37.25x10⁹ 36.57x10⁹

(h) Total connected customers 48 47 48 48

Notes

a Excludes 61km of circuits leased from others and operated by Transpower, and 34 km owned by Transpower but operated by others.

b To 2 decimal places only, higher accuracy used in calculations.

c For all years, figures for maximum demand kW and kWh injected and supplied include loads on circuits leased by Transpower. The effect of these circuits cannot be measured as metering equipment is not installed at the inter-connection points with Transpower-owned assets, but the difference is estimated to be no more than 0.1% of totals. Loads on Transpower assets leased to others are not included as Transpower does not collect operational data for these assets.

d Including sales to direct connected customers.

¹ Electricity Information Disclosure Requirements issued 31 March 2004 as amended by the Electricity Information Disclosure Amendment Requirements 2004 effective 8 May 2004 and the Electricity Information Disclosure Amendment Requirements 2006.