HARNESSING NATURAL POWER.

New Zealand Herald, Volume XLIV, Issue 13480, 3 July 1907, Page 4

HARNESSING NATURAL POWER.

I SETTING THE WATER TO .WORK. AUCKLAND'S SOURCE OF ENERGY. In* all good time the farmer who tills the soil from dawn till dark in these backward days, and cams his living by the sweat of his brow, will ait on a fence rail and. 1 smoke cigars while electricity hustles round ' and does the chores, or rips up the soil 20 furrows at a .stroke, without forgetting the i headland ; and at one o'clock on Saturday afternoon that farmer will step to his ele-gantly-appointed aeroplane and whizz off up to Samoa, or some other " islands of the blest," for a week end change of "jr.! And then the poor scribe will no longer ait at ilia desk ami endeavour to compress! •his chest into the least possible scale of inches, for he will simply have to think, •i.nd his thoughts will be registered by the all obliging electricity, the while ho shoots ; tho birds of the air with an electric gun. I Then, also, in its spare time, electricity! might even do the thinking. Tim moral I of this, flight of imagination is that this corner of the Dominion really doesn't know where it. is, or on which side its bread is; buttered, when the subject of development: of electrical energy is on the board. I There runs to waste erery day in Auckland enough x jo\ver to drive all the fac-1 tories and engines and railways and machine shops from Te Reinga to the Mokau. Any schoolboy knows, or ought to know, j .hat a body of waters with rapid fall means] ; possibility of electric energy, and it is easily apparent that Auckland has many possibilities in this line, and also in many others which are just about as much developed. Firstly, as the cookery books ■ would say, take some water, and having taken the water, run it on to a Pelton i wheel, add a dynamo or two, a few miles i of wire and; other things, and the thing i is done. Of course, the water requires to be in good volume, of steady flow, and ; with a pressure of anything up to 500 ft vertical, the more water and the .more ■- . pressure the more merrily will hum the Peltons and the dynamos. That's accessory after the fact, and the fact, first and i ?ast and all time, is tho water. ?;''■'"•'.. If Auckland never had anything else, it | would still have a source of wealth in its wonderful rivers; it has more big streams I * crowded . into a certain area of country I; than any other part of this colony, and i some of its tidal rivers are marvellous waterways for comparatively so small an | • area.- For the purposes / of this article, j ■ however, it is only necessary to deal with | one .stream, without mentioning such rivers j as the Northern Wairoa, or the Waikato. i Daily the streams of Auckland carry hunj dreds of thousands of power units to sea, : and that tremendous energy is being lost. j Tho province is daily losing great revenue j from the fact that the vast areas of native j '"■-. land are lying idle and unprofitable, and j just so—though it might not strike the | average man so Auckland is los--1 ing wealth by allowing the enormous j energy in its streams to pour out to sea, ! untrammelled and unharnessed. j- OKERE AND KAITUNA. v Those who have made the Lakes tour | from Rotorua will remember the thrilling : sensation of voyaging"" down the Ohau j Channel from Rotorua. Lake into Eotoiti, \ when tho tremendous sweep of the great current apparently carried the boat along | like a straw, and they will possibly have | just as vivid memory' of their fervent j• " thankfulness that the boat didn't essay a } mad career out of Rotoiti down the Okero j and Kaituna. ; This stream, the outlet of tho lakes, is known as the Kaituna River ! after it has passed Okere Falls, and from !'. Rotoiti to a point some eight miles down i****%j this great torrent'is one of the most inI"' " N teresting streams .in Auckland province. }• . From the bridge just below the outlet one j ; ■ sees a broad .bine flood sweeping with | glassy curve onto the first aipid, and then ; 0 churning to surf, and the contrast of. the | deep blue and the snow white, with the: j framing of the tender green of the luxuri-! j. ant foliage oh the. banks, and the wide' j expanse of the beautiful lake as a backt : ground, forms one of the loveliest pictures ;!". in the whole-of Auckland. That water is ;[' getting away as fast as it knows how, [| it is in the tallest kind of a hurry, booked ji right through, and no side stations on the f ' whole line, and it roars through the gorge ij which narrows in just below the bridge, I , ' flashes over the falls without stopping to j look, and gets away down country. Why II doesn't that stream flow placidly and calm[i , ly, with little gurgles and chuckles in the bends and smooth, clear reaches in the i straight? The answer is in one word, fall. [ And faD, where water is concerned, means possibility for electric energy, and it is that possibility that singles out the Okere or Kaituna as one of the most important streams in Auckland just now, for the energy running to waste there is figured out at upwards of 50,000 brake horsepower. ." What these figures mean will be understood when it is stated that if 44,000 or 45,000 of that horse-power were substracted there would still be enough to supply •Auckland City with all the electricity it j could use for a good long while. The curve down onto the first rapid is 915 ft 1 above sea level, and a major portion of :| that elevation is used up within eight miles, and it is its rapid fall which has attracted the attention of electrical engineers throughout the Dominion. Within three- || quarters of a mile of that first rapid there is a fall of 100 ft, with a minimum flow of ! | 500 cubic feet per second, and the energy that could be generated from this section, j alone is over- 5000 brake horse-power, J while ' within eight miles there is fall |j ■ enough to givo upwards of 50,000 horse- ! power, truly an enormous asset. Within five miles, in fact, survey has demonstrati ed the existence of over 30,000 available j horse-power. | OVERLAND TRANSMISSION LINE. I An overland transmission line from the j Kaituna to Auckland would be 130 miles in l ! length. Of course, there is heavy loss of |J power in transmission over great distances, tj but every day electrical engineering is |j striving for the irreducible minimum of 1 loss, and sooner or later it will be possible i to convoy power such distances with scarcesi ly noticeable loss. Still, big as the loss in I transmission would necessarily be, it must | lie remembered that the available power is I enormous, and that power is conveyed far greater .distances in America and other countries than 130 miles. A concrete ex- ! ample distances in America 5000 other countries than 130 miles. A concrete example is the transmission of 5000 horsepower, for just on 100 miles, to the Kolar t .mines, in India, with the loss of 1000 h.p. •]} en route, so that with up to 50,000 b.h.p. ! : available, there is no insuperable obstacle l to the profitable transmission of electricity j from Okere Falls to Auckland City. There j is no necessity, at this stage, to enter at | length into illustrations of what is done 1 elsewhere, except to say that in nearly all I very long transmission lines provision is j" made for tributary stations; that is, it has ■I been found in practice, where great power I is needed, that small generating stations I en route over and over again recouped I their cost by making up ' the loss. j The point of this is that the Kaituiiii j : scheme is most admirably furnished with o i tributary scheme in the Horohoro, which I would make a half-way auxiliary. Capable js engineers have estimated that a power sta j'j tiort at Horohoro could generate sufficient H energy to deliver 5000 brake horse-power If I Auckland City at a total outlay of £250,000 i J which would include distribution along tin I main arteries. Then there could be brought |) to Horohoro station from the Kaituna an || other 5000 brake horse-power, and, o II course, further supplies of power would hi \\ tapped as needed, and at proportionately fj less cost. It stands to reason that then II must be annual cost for wages, wear am ! tear, etc., but that also holds good witl U • steam or any other power. The fact re H mains' that a wonderful source of electrica II energy lies within practicable distance o Ij'; the city, and that, while for requirements [j now 6000 horse-power would perhaps nice if the case for the city, there is a great re || serve of over 40,000 horse-power, whicl |j , . could be added with comparatively a smal |j further outlay., i

GENERATING STATIONS. f. At Okere Falls now there is a powerhouse generating electricity for Rotorua township, where about 120 horse-power is delivered by a transmission line of 13 or 14 miles in length. This generating station was in the manner of an experiment, and the margin allowed for development was too small. How really small this scheme was is illustrated by the fact that the powerhouse is only a-quarter of a mile from the lake outlet, and a fall of 14ft only has been taken, and that with a Hunting some 83yds in length. Half-a-mile below the power station over 5000 horse-power is available, | and lower down again, with a iluming, or race, of seven or eight miles—a mere bagatelle on any goldfield— to 50.000 horse-[ power could be generated. The Public j Works Department instituted surveys in 1904, and again in 1905, of numerous possible sources of supply, and the surveys demonstrated what a valuable asset the Kaituna Riverffleally is to Auckland, and the Minister in charge of the Department stated not long ago that the Kaituna was the power source most likely to be developed in Auckland province. There are prac- . tically three stages in connection with the | Kaituna scheme, a 5000 horse-power stage ! half-a-mile below the present power station, a 30.000 horse-power stage between [four and five miles below the power-house, : and a*50,000 horse-power stage eight miles , away. With two large generating stations, the 50,000 horse-power would be ]easily available, and with a small generating | station at Horohoro as auxiliary, Auckland |could have all the electric power it would • want for many years to come, i j FIELD FUR THE POWER. J I There is no necessity at this stage to eniter into the comparative costs of electric, i j steam, or gas engine powers, as these com- ; parisons are worked out to exactness by ! text-books, but the first consideration in viewing a scheme for electrical power is the I probable cost to the consumer, and. without entering into lengthy calculations, it may bo taken, from engineering estimates ! and reports, etc., that the Kaituna scheme would supply Auckland City with elec- . tiicity at a cheaper rate than is charged in i Wellington, Christclnireh, or Dunedin. In . I Auckland, with a good installation, the !j price to users of power for factories, etc., j would work out at about £8 per horse- . power, for a 24-hour supply, per annum, . j Factories, however, do not run 24 hours J per day, and the same cost -#euld have to be met for eight hours as for 24, but us the lighting of streets aud dwellings and shops ' comes in at night, the factory should receive its power for about £5 for an eighthour supply per annum of one horse-power. Roughly, the Kaituna should serve Auck- - land with lighting at 4d per unit (equal to about 32 eight candle-power lamps for one ' hour) to private consumers, or at 3d per ' unit to local authorities for distribution, ' and with power for small installations through meter at about 2d per unit (equal, for power, to about one horse-power per ' hour of actual use). The many fine uses ' to which electricity can be put, its convenience, and in some respects its advantage ' over steam or gas, at once promise electri--1 cal energy a. splendid commercial field in Auckland City and district. It has been ' | the experience, though the contrary was 1 long anticipated, that installations of elecj tricity have not diminished the use of gas. ''[but, curiously enough, the gas consumption ; has actually* increased. Auckland now is ; a great manufacturing centre, and it is 1 growing at such a rate that every year ' marks decided progress, so that the power ' its factories and workshops, its lighting, 1 and its heating absorbs, opens up a fine field for electricity. It is not a. want of the future by any means ; there is big demand for electricity now for private use, ' apart from its possible use for street light-j i ing, and the question of a comprehensive electric power scheme for Auckland is very much within the region t,i practical poll-J ' tics. For, of course, the supply from the : installation at the destructor will be only a ' very small item, compared with the possi- - bili'ty the city of Auckland and the many - smaller centres offer as a field for a reason- > ably cheap supply of electric power, and • therein lies the necessity for setting the ' water to work, and harnessing the wonder- '■ ful energy now going out to sea.