DEMAND FOR POWER

Evening Post, Volume CXXIII, Issue 117, 19 May 1937, Page 12

DEMAND FOR POWER

ARAPUNI EXTENSIONS

42,000 KILOWATT ADDITIONS

STANDBY PLANTS RUN

The c.apacity of a country, any country, to' consume electrical power a]> pears to be almost unlimited, and New Zealand has as healthy an appetite for power as any of them, iThe appetite still increases, so that at the present time Arapuni, Waikaremoaria, and Mangahao hydro-electric' stations, are running at practically full ■ capacity, with the full winter demand still, to be developed. . '■"•..'..'.. In Wellington City the demand . for power is already almost up to. the highest level of the winter of 1936, but tha peaks will climb considerably highef next month and in July and August. In the Auckland Province, supplied from Arapuni, the demand has already exceeded the maximum .consumption of 'last winter by at least 10,000 kilowatts and for- some days past the Auckland Power Board's steam plant has been called upon to "cut the peak"' for tha two hours or so, from 4.30 to 6.40 p.m., when the demand is heaviest.,; Actually no great.amount of power has been taken from the steam station, "sa that there is an ample margin pending the completion of extension work : ia hand at Arapuni. \ ';•'. : - NEARING FULL DEVELOPMENT.' Construction work at Arapuni. was commenced in 1925 and the first, unit, 15,000 k.w., was brought into operation in '1929. Two more "units were running by March, 1930, and a fourth in 1932, giving a total capacity of 60,000 k.w. capacity. The extensionl will almost double the capacity, for each of the two new units will, be of 21.000 L k.w. and, within a few years, as the .demand still climbs upward, as it assuredly will do, two more 21,000 k.w. units will b« (installed, and the Arapuni development will be complete, for the eight. units (will take the full normal flow of tha fWaikato River, and the spectacular fall tfrom the upper level to the flat of tha bid buried forest will, when the generators are under full load, disappear. i When, in 1925, an ultimate development of 140,000 k.w. for. Arapuni was sjpoken of the'plan was looked upon V*y many people as an engineering pipe ctream, for the year when the whole of the North' Island, let alone, tha northern section, would consuma 1< SO.OOO kilowatts of power was in tha frir future distance. The engineers, k. lowing what had happened in every ot her hydro-electric system, had their ovm ideas and went ahead, and already they are looking beyond the present extension work and are planning fof oth'ter extensions of the power supply system of the North Island. In the Smith Island there -is still, with; the Wa.jtaki scheme, a. substantial margin of c sapacity, over demand.;, . ,; ; POWER-HOUSE EXTENSION. Tl»s work, at Arapuni -includes tha extension of the power-house by an addition 231 feet long, with a depth of 46 f<!et and a height from ■ floor to paraiiet of 56 feetAwith: verv,heavy foundation work, going down as much as 40. 'ieet below floor level. When m 1930 ; m earth ; movement necessitated the closing down of the station while remedibl work was- carried, out penstocks :(the great sloping waterways which .tarry the water from, the uppef level to the turbines in the powerhouse) tvere driven for two additional units" (fcbose which are being installed now) anki the full intake construction in the urfeer river level, was completed. The extension to the power-house wjll complete (the building to the full capacity required to house the. last two 2100 k.w.i units,- so ; that the present work is at major development which will makeVthe final additions a comparatively ; straight-ahead engineering work. ■ ' ■■ : THE WA. IKAREMOANA SYSTEM. The full .development at Arapuni will meet the' requirements ■of the northern paitt of the Island for some years but meanwhile the southern provinces aski for more,and more, and development be long delayed Mangahao cannot be further extended and though bjr the original plans Waikaremoana web to be developed to a three-stage station with a total output. of over 100,000 k.w., extremely difficult conditions V have till now'limited the output to 32,000 k.w.'torn two units in the middle levelstation. A-com-mencement was .made upon construetibiLto control the *™°t.™**trcm the We to mak<? possible -the building of the high-level Astation, but the-work, which entailed'ti he boring of a tunnel waterway through country which was known to be dim cult, was stopped.last year after an insi»ection by the Minister of Public Works. ■_ The present station has two units, each of 16,000 k.w. sand a third^unit, oi the same capacity, is on order, but with the present :ftow of water from the lake it will itot be possible to operate the three v nits at full capacity throughout the yeat, though probably during the months pf greater demand there will be ample vvater, _ If the No. 1 statitfa cannot be.proceeded with, in th<! near future, at any rate, there remains the low level, No. 3 development, >- from which a further 32,000 k.w.may be .obtained, and this is a work wbtch will probably have its place on Public Works plans and estimates of the n text two or threa y6The Evans Bay s team ..station. 4s operated each afternoo.u to cut the high peak from the city den land and during the colder winter..metotha will take over a considerably-greater part of tha Wellington load.. With Hhe new plant which is now 'being installed the station will give a wide ma rgin lor a considerable time to come, but a working agreement between the E fepartment and the corporation has mfiny points pi difficulty, and for almot* a full year negotiations have proceed between the two bodies. However! if ing up of. a rmutuallV-satisfactory agreement as to the payn Sent for bulk supply presents difficulties, the capacity of the Evans Bay Elteam station to afford a substantial m.fesure or assistance to. the hydro.. sy:ttem assure* output sufficient to meet gtill-mcreas-ing demands. -__ ■