69

D.—l

The total of the maximum loads was 42,157 kw,, as compared with a total installed main capacity (apart from special auxiliary plants) of 49,630 kw., showing a margin of 7,473 kw., or 15 per cent, of spare plant, and this in spite of the fact that many of the stations have been seriously overloaded— pointing again very strongly to the advantage of interconnecting all available power sources, thus increasing the working-capacity of the system as a whole by reducing the margin of spare plant required and enabling every station connected to the system to come to the assistance of any other that is in trouble. Definite plans are in hand for the interconnecting of the Thames and Te Aroha plants with Horahora, and Akaroa with Lake Coleridge. Several other proposals for interconnection have been made, including Lake Coleridge and Waipori Falls, and the interconnection of the whole of the six Taranaki power-stations and of the three Bay of Plenty stations. Pending the completion of the large Government hydro-electric stations this policy of interconnection of the existing smaller plants will be of the utmost assistance in enabling the present small plants to carry on to the best effect until the larger sources of power are in operation. With regard to the seventy-four authorities operating the fifty-seven stations and seventeen distribution systems taking bulk supply from a larger power authority, these are distributed as follows :—

The total number of consumers at the end of the yea.r was 73,151, as compared with 58,449 at the beginning of the year, an increase of 25-2 per cent. The total length of reticulation-line in the Dominion is about 2,260 route-miles, and of trans mission-lines about 360 route-miles, totalling 2,620 route-miles. The average number of consumers per mile of reticulation is thus 32-3. The population, according to the 1921 census, of the districts already supplied amounts to 684,175 out of a total population of the Dominion of 1,218,270 ; but the population already supplied consists almost entirely of residents in the cities and boroughs, and the important function of supply ing the farming and country consumers is only now being taken up by the Electric-power Boards. The units generated during the year in the fifty-seven power plants amounted to 149,476,379, of which 124,446,459 were sold or accounted for to 73,151 consumers, and 25,029,920 were lost or unaccounted-for, showing an overall efficiency of distribution amounting to 16-7 per cent. The units sold per consumer, after deducting 33,278,932 units for tramway supply, were 1,246, and the units sold per head of population supplied were 133. The maximum demand (42,157 kw.) was 0-576 kw. per consumer, or 0-061 kw. per head of population supplied. The aggregate of eight tramway peak loads was 13,240 kw. and is included in the total of 42,157 kw. The present demand in Canterbury is 0-063 kw. (0-084 h.p.) per head, and in Dunedin 0-082 kw. (0-109 h.p.) per head. These figures are important owing to their bearing on the estimate of the future demand irom the large Government schemes under construction which is taken as o'ls kw. (i.e., 0 - 2 h.p.) per head of population— practically double the present supply per head in Canterbury and Dunedin. Although the industry, as a whole, yielded a net profit of £68,106 for the year after paying interest and sinking fund of £233,078, it will be noted from Table G herewith that out of the seventy four systems thirty worked at a loss. This is due mainly to the increasing costs of supply, and the difficulty in raising the charges to keep pace with these increases. Several applications were received during the year for increases in the maximum charges permitted by license, and in most cases were justified by the circumstances. In other cases, such as Auckland and Wellington, the increased cost of coal has necessitated increasing the charges, though still below the limits allowed by the license. It is hoped that costs have already passed their maximum, and will shortly show a falling tendency, enabling those stations which have been operating at a loss to recover their financial position, and with increasing output and improved economies to offer a reduction in charges to the consumers. With regard to the standardization of the systems of supply there has been practically no change during the year, but several of the older installations are preparing to change over to the standard three-phase 50-cycle system, which now includes 29,980 kw., or 54-3 per cent., of the generating plant installed in the Dominion (55,461 kw.). The annual load-factor of the whole output of the fifty-seven stations for the year, amounting to 149,476,379 units, with a maximum demand of 42,157 kw., has been 40-4 per cent. This is the average

i i Capacity in Kilowatts. ! I Proportion per Cent. Ownership. Number. Government Departments.. City Councils Borough Councils County Councils Town Boards Pri vate Electric-supply companies.. Industrial companies 3 4 11 5 8 2 6 2 3 12,500 17.610 8,194 Bulk 436 113 1,408 2,700 12,500 22-60 31-70 14-70 0-79 0-19 2-55 4-87 22-60 Tramways Totals 74 55,461 100-00 I