D.-lB

6

It appears, therefore, that the cost of the hydro-electric plant at Arapuni should not cost more than £20 per horse-power of plant if the scheme is to be economically successful; also that the expenditure on transmission-lines should for the same reason not exceed £20 per horse-power of plant. The aggregate expenditure should therefore not exceed £40 per horse-power of plant. (39) The Lake Coleridge plant has already cost £45 per horse-power of plant installed, or approximately double the estimated cost of £23, and it appears to be necessary to provide a stand-by steam plant in Christchurch. (40) The proposed Arapuni hydraulic works are admittedly more expensive than those at Lake Coleridge, and the transmission-lines required will be at least twice as long. It will also be necessary cither to duplicate the transmission-lines or to provide a stand-by steam plant in Auckland. (41) In view of these considerations, can it be expected that the estimated cost of the Arapuni scheme —£40 per horse-power of plant installed—will be realized ? (42) Is it not more probable that the estimates will be largely exceeded, perhaps doubled, as has been the case with the Lake Coleridge scheme ? (43) Even if the estimate of £40 should be realized, it has been shown that current cannot be supplied in Auckland as cheap as the cost of generating by steam in the City Council electric station. Some Interesting Comparisons. The question now to be considered is, What effect will the Arapuni hydro-electric scheme, if carried out, have upon the business of the Auckland Gas Company (Limited). This question has been already answered, as it has been shown that the City Council Electric Station is at present generating current cheaper than it can be supplied from Arapuni, except the hydroelectric current be supplied at a loss. The capital expenditure of the Auckland City Council Electricity Department was £335,411 18s. at 31st March, 1917, and of this amount about one-third, or £109,927 55., had been expended in machinery, transformers, &c. It is not clear that there could be any saving in future expenditure under this head. Even if steam-engines and boilers wore not required, transformers would have to be provided, and it does not appear that engines and boilers can be dispensed with except the transmis-sion-line be duplicated. Any such duplication would certainly add largely to the cost per horsepower of plant installed, and would have to be charged for in the price of current delivered to the Auckland power-station. The following is an analysis of the costs per unit generated and sold by the City Council Electricity Department for the year ending March, 1917 : — Price per Unit Price per Unit generated. sold. Generation of electricity — d. d. d. d. Coal .. .. .. .. •• 0-3389 0-4031 Oil-waste, stores, and water .. .. 0-0132 0-0157 Wages, gene rating-station .. . . 0-1050 0-1249 0-4571 0-5437 Repairs and maintenance — Buildings .. 0-0380 0-0452 Engines and boilers . . . . . . 0-0429 0-0511 Instruments and tools .. .. . . 0-0153 0-0182 Dynamos, exciters, transformers .. . . 0-0042 0-0050 Accumulators .. .. .. .. 0-00177 0-0021 0-10217 0-1.216 Distribution of electricity — Wages, repairs, and maintenance of mains and meters .. .. .. .. 0-0749 0-0891 Public lamps .. .. .. .. 0-0185 0-0220 Management — Salaries and office charges . . .. 0-0721 0-0857 Special charges .. .. .. .. 0-0576 0-0684 Bad debts .. .. .. .. 0-0058 0-00688 Interest on loans .. .. .. 0-42384 0-5040 Depreciation .. .. .. ~ 0-2618 0-31137 Sinking funds .. .. .. .. 0-06196 0-07368 Average cost .. .. .. 1-2958 (? 1-5357) 1-82643