A HUGE INCREASE

Evening Post, Volume CXXVI, Issue 77, 28 September 1938, Page 15

A HUGE INCREASE

DEMAND FOR POWER

PLANNING YEARS AHEAD

Included in the annual report of the Tramways and Electricity Departments \ issued by the General Manager, Mr. \ M. Cable, is a graph illustrating the * extraordinary growth of the demand for electrical power during the past sixteen years—threefold since 1924-25, twofold since 1929-30, to a peak during the winter of 1937 of over 29,000 kilowatts, which is substantially higher than the generating capacity of the Evans Bay standby station or, for that matter, of Mangahao. In 1922 the demand just topped 8000 kilpwatts and there it hung till 1924, when the curve turned more sharply upward, notwithstanding difficulties of supply in the summer of 1927-28, when Mangahao was overloaded and Waikaremoana and Arapuni stations.were not yet interlinked in the North Island hydro-electric system, to 1931, when a peak of 18,500 kilowatts of city demand was reached. There was a fall to 17,600 kilowatts in 1933-34, then a climb to over 21,000, a halt for a year, and thereafter a rise to 23,000 in 1936-37, and a second climb during 1937-38 of 6000 kilowatts, to 29,000. Since the report was drawn up another winter peak has been recorded, of 32,000 kilowatts. HUNDRED MILLION UNITS. A second line on the graph shows the output of power, for lighting, heating, tramway, and power purposes in millions of units. In 1922 about twentyone million units were used in the city, in 1928-29 forty millions, and in 1934-35 sixty millions. Eighty million units were consumed in 1936-37, and in 1937-38 over ninety-five million units. Of these (in round figures) fourteen million units were sold for private lighting, thirteen and a half million for power, forty-five million units for heating, over a million and a half for street lighting, and nearly eleven million units for tramway purposes. Eleven million units were used for station operation, and in the inevitable losses of conversion and distribution. The exact figure of units purchased from the Government or ' generated at Evans Bay was 95,584,333 units. The total will be far over a hundred million units for the current , year. ; There were at March 31 28,022 . domestic consumers,. 7499 commercial ' users of light and heat, and 2615 power , consumers, a total increase of about [ 1400 on the previous year. r The average revenue per unit sold , for private lighting was 2.85 d, and for [ heating .56d. Power units brought in [ 1.14 d, and tramway power averaged , .75d per unit. The average revenue per [ unit for all purposes was just over a . penny, 1.06 d. i PLANNING YEARS AHEAD. ! So phenomenal has been the increase in demand that difficulties in maintaining supply might well have been expected; that no difficulties or serious ' interruptions occurred is evidence of ' the foresight exercised in planning the 1 extension of the city service, in feeder \ lines, transformer stations, reticulation, 5 and the complex system of control, 1 for as a water main and pumping sta- : tion can handle so much water, and no more, so feeder lines and street reticuJ lation, transformers, and control can : deliver to consumers only the amount " of electrical power for which they are " designed, and that design must be based 5 upon an estimate of demands to be ; met five and ten years ahead. That ; responsible work of estimating future 5 requirements is going on from day to [ day, for the certainty is that the peak of 32,000 kilowatts of the last winter will be passed again.