81

D.—l

Table A.—Electric-power Supply of New Zealand for the Year ended 31st March, 1925.

Daily Load Curves. The question of the daily load curve and the ratio of the average load to the maximum load or the load-factor is an important one in determining the selling-price of electric power. Each station must ascertain its own load-factor and determine its selling policy accordingly. As a general guide the daily load curves of fourteen of the larger stations of the Dominion have, by the kind co-operation of the engineers to these places, again been obtained for two days of the current year—viz., Friday, 13th March (representing equinoctial conditions), and Friday, 26th June (representing midwinter conditions). Friday has been selected as the late-shopping night in most places, thus representing the most extreme conditions of loading. These fourteen stations have an installed capacity of 74,313 kw., or 91 per cent, of the total installed capacity of the Dominion, so that the resultant curves may be taken to represent quite accurately the shape of the load curve of the combined output of the whole Dominion. Water-power and fuel stations are proportionately represented, including all the large stations of each type, and the diagram includes not only the total output, but the waterpower and fuel-power outputs separately. The summation curves are plotted in Fig. 3, and the results are as follows : —

Table B.—Summer and Winter Typical Loads.

These are daily load-factors. The annual load-factors are, of course, substantially lower, being 48-2 per cent, for water-power, 36-2 per cent, for steam-power, and 42-5 per cent, for the whole output of the Dominion.

11—D. 1.

Water. Steam. Gas. Oil. ! Total. Number of stations ...... 33 7 14 2 56 Average capacity (kilowatts) .. .. 1,160 5,560 249 553 1,462 Number of consumers .. .. .. 84,134 50,993 10,234 3,338 148,699 Installed capacity (kilowatts), (main plant 38,354 38,925 3,491 1,106 81,876 only) Maximum load (kilowatts) .. .. 38,813 26,016 2,504 755 68,088 Units generated .. .. .. 163,786,074 82,342,500 5,812,643; 1,858,701 253,799,918 Annual load factor (per cent.) .. .. 48-2 36-2 26-5 1 28-1 42-5 Units sold .. .. .. .. 128,766,428 64,296,213 4,679,052 1,570,210 199,311,903 Total capital outlay* .. .. .. £6,181,893 £2,755,505 £528,277 £100,914 £9,566,589 Total capital per kilowatt installed* .. £161 £71 £151 £91 £117 Total annual working-costs .. .. £384,162 £319,120 £62,829 £14,715 £780,826 Total annual working-cost per unit sold .. 0-72d. l-19d. 3-22d. 2-25d. 0-94d. Total annual working-cost per kilowatt, £9-9 £12'2 £25-1 £19-5 £11-5 maximum Total annual capital charges .. .. £449,011 £244,115 £31,507 £7,453 £732,086 Total annual capital charges per unit sold 0-84d. 0-91d. l-62d. l-14d. 0-88d. Total annual capital charges per kilowatt, £11-6 £9-4 £12-6 : £9-9 £10-8 maximum Total annual capital charges, percentage of 7-3 8-9 6-0 j 7-4 7-6 capital outlay Total annual costs .. .. .. £833,173 £583,755 £94,336 j £22,168 £1,533,432 Total annual cost per unit sold .. .. 1 l-56d. 2T0d. 4-84d. : 3-39d. l-85d. Total annual cost per kilowatt, maximum £21*5 £21'6 £37-7 £29'4 £22-5 Total annual revenue .. .. .. £913,638 £627,158 £92,683 i £25,836 £1,659,315 Total annual revenue per unit sold . . l-70d. 2-34d. 4*76(1. 3'95d. 2*0d. Total annual revenue per kilowatt, maxi- £23-6 £24-1 £37-0 £34-2 £24-4 mum Net profit, .. .. .. .. £80,466 £43,403 .. £3,668 £127,537 Net loss .. .. .. .. .. .. £1,653 .. £1,653 Total net profit .. .. .. .. .. I .. £125,884 I ' • . * Includes distribution.

(Fourteen Power-stations.) Installed Maximum] TT Daily LoadCapacity. j Load. nl s " , factor. ' I • I March 13th, 1925 — Kilowatts. Kilowat Per Cent. Water-power .. .. .. 32,925 29,072 497,794 71-3 Fuel-power.. .. .. .. 40,988 24,315 219,380 37-6 Totals .. .. 73,913 48,001* 717,174 62-3 June 26th, 1925— Water-power .. .. .. 32,925 32,890 537,720 68-2 Fuel-power.. .. .. .. 41,388 32,120 266,305 34-6 Totals .. .. 74,313 56,325* 804,025 59-5 * Combined maximum.