POWER DEMAND MARGIN

Press, Volume LXXV, Issue 22659, 14 March 1939, Page 10

POWER DEMAND MARGIN

MISGIVINGS OF M.E.D. MANAGER LIAISON AUTHORITY SUGGESTED “TO STRENGTHEN CONFIDENCE” The establishment of a representative supply authority committee, to work between the Government and the distribution authorities, is strongly recommended to the Christchurch City Council by Mr E. Hitchcock, general manager of the Municipal Electricity Department, in his annual report. Dealing with the problem of future power supply, Mr Hitchcock writes: — “It is a regrettable and unpalatable task even to appear to criticise the planning and provision of another organisation. Government monopoly of generation and transmission is an established and accepted principle. The dependence of purchasing supply authorities upon it is almost complete. Such a principle and method can,' however, be sound only if adequate future supply is assured. “For the relationship between generation and distribution authorities to be no more than a buyer and seller relationship appears not to be enough. There is required sufficient mutual understanding, shared information, and foreknowledge, to strengthen confidence. A recognised liaison body, such as a representative supply authority committee, if only with consultative status, would be a great advance. The vintage will fare badly if the branches have little knowledge of the vine. The present position is just that. The Dominion generating authority owes it to Dominion consumers that available plant capacity shall be maintained at some reasonable margin over known demands. To allow this necessary margin to fail would regrettably mar what has been of inestimable value to this country—Government hydro-elec-tric supply.” During th* year under review, the department had, in common with other supply authorities throughout the Dominion, experienced an exceptional increase of load. It was a matter of some difficulty to determine how much of this was growth of load and how much recovery from the depression period. The Government’s ColeridgeWaitaki system, from which the Christchurch City Council receives its supply, had a present installed plant capacity of 64,500 kilowatts. The maximum loads for the last three years on this system had been as follows: — Kilowatts. Winter, 1936 .. .. 44,520 Winter, 1937 .. .. 51,860 Winter, 1938 .. .. 60,520 “These figures draw attention very strongly to the question of future supply,” concludes the report. “Arrangements are being made to carry supply from the Coleridge-Waitaki system to the West Coast, to Otira, to Otago and Southland. With present plant capacity and what is in immediate prospect, this department, as one of the supply authorities now dependent upon the Coleridge-Waitaki system, cannot contemplate these measures without anxiety.” „ The growth of the Municipal Electricity Department is illustrated by the following tabulation:—

Pumping o£ Water The threat of a power shortage is also referred to by the City Engineer (Mr A. R. Galbraith)' in his report on thevcity’s water consumption. It reads; —“The steady increase in water consumption evident over the last few years was again experienced in 193738. This substantial rise was not due to a long spell of dry weather, but was due to the increased number of water connexions which went up by approximately 400 in the last year. Owing to the desirability of not pumping during electrical power peaks, attention has been focused upon the necessity of installing a larger reservoir and some form of standby pumping plant to be in action when electrical power is not available. Christchurch is most favourably treated by Nature In having a pure, abundant, and widespread water supply readily and

easily available when and where required. The sub-station system has been "developed to utilise these natural benefits to their utmost, and the prime necessity for efficient sub-station operation is a continuous electrical supply. ■ “If this is not available from hydroelectrical sources, then it must be provided in othej: ways, and this is a matter which should be very carefully examined from every aspect as soon as possible in order to enable the city water supply system to be put on a satisfactory footing. This necessity of a safeguard against prolonged interruptions in the power supply has been brought before the council and its committees from time to time during the last 10 years, and with the realisation of more prosperous times it is hoped that action will become possible.”

1920 1930 1938 Units sold 80 J (millions) 10 47i ' Max. load 23.425 (K.W.) 2,996 ,13,340 Revenue £68,542 £226,829 £268,787 Capital outlay £302,185 £707,703 £924,376 No. of sub103 stations 27 61 Route miles of low tension 273 line 155 243 Route miles of 11,000 volt 81 i distribution 17 41J No. of consumers 9,554 30,693 35,187 Total staff 134 194 222 Average Revenue a Unit — Domestic ,. 2.965d 1.18d .701 d Commercial .. 4.380d 2.45d 1.605d Industrial .. .827d .88d ,721d Candlepower of street lamps 234,850 430,950 591,950 Total No. of lamps 1,885 3,294 3,933