71

"D.—l

taken into account. The curves show an increase in demand of about 4,000 kw. in the daytime and 8,500 kw. in the afternoon between 4 and 5 p.m. The relative shapes of the summer and winter curves are also important, the winter curves showing a peak between 4 and 5 p.m., and the summer curve between 8 and 9 a.m. It is rather surprising to note that even under present New Zealand conditions the all - day demand is so high, and with the large development of hydro-electric power and the consequent increasing industrial and cooking load the evening demand will become a still smaller proportion of the daily peak load. The two curves show the following results : —

It will be noted that the fuel plants with their higher average charge per unit show a distinct evening lighting peak load, and consequently a much lower daily load-factor (503 per cent.), than the water-power plants (72-7 per cent.), for which the peak load occurs in the daytime. Coming now to the general technical and financial results of the operation of the whole of the electric-supply systems of the Dominion analysed according to the source of supply, they give the following results : —

Inspections. During the year the following electric-supply systems were inspected, viz. : Patea, Waverley, Feilding, Bull's, Hawera, Stratford, Waitara, New Plymouth, Kaponga, Inglewood, Eketahuna, Pahiatua, Hastings, Napier, Reofton, Picton, Tai Tapu, Brightwater, Hokitika, Westport Company (Denniston), Westport-Stockton Company (Ngakawau), Bluff, Mataura, Winton, Gore, Oamaru, Timaru, and Ashburton. These were done as opportunity offered, and represent less than half the number of systems. Hitherto the duties of Inspecting Electrical Engineer have been performed by one officer, but with the increase in the amount of inspection work it has not been possible to get round all the systems during the year as has previously been done. With the inception of the Electric-power Boards, together with new supply-stations, the demands on the Inspecting Electrical Engineer are rapidly increasing, and proposals are being made for the delegation of some of the routine inspections to District Engineers, but still subject to control from this office. In order to reimburse the Department for the expenses in connection with inspection work a schedule of fees has been drawn up and is now in force.

Date. Units Output. Maximum Load. Daily Load-factor. 30th September, 1920 30th June, 1921 .. 413,000 512,543 Kilowatts. 25,305 33,684 Per Cent. 68-0 63-5 For the latter date the total load curve o: : rom the ten fuel-plants and each plotted sepai E the five large wi •ately, showing th iter-power plants j following results las been separated Units Output. Maximum Load. Daily Load-factor. Water-power Fuel-power 302,585 209,958 Kilowatts. 17.357 17,400 Per Cent. 72-7 50-3

Water. Steam. Gas. Oil. Total. Number of stations Num bcr of consumers Installed capacity (kilowatts) Maximum load (Idlowatts) Units generated Units sold Total capital outlay Capital outlay per kilowatt installed* Total annual working-costs Annual working-costs per unit sold Annual working-costs per kw. p.h. max. .. total annual capital charges Annual capital charge per unit sold Annual capital charge per kw. p.h. max. .. Total annual costs Total annual costs per unit sold Total annual costs per kw. p.h. max. Total annual revenue Total annual revenue per unit sold Total annual revenue per k.w. p.h. max. .. Net profit 26 37,647 28,883 21,661 91,334,719 74,686,598 £2,379,530 £82-4 £181,425 0-58d. £8-35 £157,801 0-505d. £7-3 £339,226 l-08d. £15-65 £383,449 l-23d £17-7 £44,223 10 23,509 22,120 17,587 50,848,365 44,478,349 £881,481 £72-8 £205,401 2-46d. £22-5 £50,891 0-61d. £5-58 £256,292 3-07d. £28-08 £283,899 3-39d. £31-0 £27,607 19 8,752 3,648 2,379 5,616,528 3,869,188 £336,145 £92-1 £72,403 4-48d. £30-4 £20,190 l-25d. £8-48 £92,593 5-73d. £38-88 £87,151 5-4(1. £36-5 £6,949f 2 3,243 810 530 1,676,767 1,412,324 £72,125 £90-0 £20,019 3-4d. £37-9 £4,196 0-71 £7-9 £24,215 4-ld. £45-8 £27,440 4-65d. £51-6 £3,225 57 73,151 55,461 42,157 149,476,379 124,446,369 £3,669,518 £81-0 £479,248 115d. £14-5 £233,078 0-56d. £7-05 £712,326 l-71d. £21-55 £781,939 l-87d. £23-65 £68,106 itlon. f L< Includos distrlbi )ss.