From DAM and DYNAMO

Cue (NZERS), Issue 27, 15 July 1945, Page 1

From DAM and DYNAMO

j mystery barely probed a century ■Di ago—today the miracle of the modern age. Such, in a nutshell, is the record of electricity, which in New Zealand, as in every other corner of the globe, has come to be such a cornerstone of everyday home and industrial life.

- Mankind has only comparatively recently discovered' how useful electricity can be, for Nature down the ages has .kept the secret well. And yet its development since its mysteries were first unravelled has been rapid. It was in 1831 that Michael Faraday discovered the principle of the modern dynamo; today, electricity gives the world light, heat, and power in unlimited quantities. We have seen electricity go to war with deadly efficiency and effect, and not until the pleasant days of peace return will we know the full story of the part it has played in ensuring the survival ■ of international law and order.

. But its possibilities halve only begun to be tapped. In the days to come it will bring about ’ new miracles as scientific research opens up fresh fields for its employment. Electricity, is go. ing to* help build the post-war world. What is New Zealand doing about it -New Zealand, with its plentiful sup. ply of water-power for the development of electricity and its wide scope for the use of the electrical energy that can be generated ? The major power projects put into operation in both North and South Islands before the war are well enough known, but

the serviceman or woman overseas" is probably not completely conversant with the position as it stands at the present time, particularly as it affects development either actually in hand or planned for the future. To obtain a comprehensive picture of the way in which the power resources of the Dominion are being harnessed it is necessary to examine all three categories. ’ '

Reefton was the first town in New Zealand to generate electricity ' for public use. The operation of its tiny plant began in 1887, fust five years after the first public supply systems in England and America had been set In motion. \ ' .A

In the following year Wellington became the first city in the Southern Hemisphere to adopt an electric public lighting system, when a private company was authorised to light the streets with 500 carbon filament lamps, the power for which was drawn from two water > turbines fed from the city mains. Private consumers in Welling,, ton were supplied with electric lighting in 1893. ■ Hydro-electric plants were installed at Patea, Hawera; Stratford, and Rotorua about. 1900; Bluff * , and Christchurch acquired steam-dri plants, in 1903; other

hydro plants sprang into being, including that at Waipori, put into operation by the Dunedin City Council in 1907; and in 1908 Auckland installed a plant similar to that in Christchurch. ‘ New Zealand was by now becoming electricity-minded, and, as was only natural, ' a demand for power supply

came from the rural districts. Canterbury ,took the , lead ; in' this respect in 1917, followed by Auckland about 1920 and Wellington about 1924. Most provincial towns' were reticulated in the . few years after 1913, and the reticulation of the rural districts was begun in earnest in the period from 1920 onwards. , To illustrate the growth of the Dominion’s power load it is necessary

to go back to 1903, in which ye ar water-power to the extent of 9,913 horse-power was available. Ten years later the figure had risen to 34,956 horse-power, and by 1923 to 54,244 horse-power. The succeeding decade produced a big leap, with 328,708 horse-power available by 1933. By 1941 there had been a further increase of forty-eight per cent, to 484,912 horse-power. A year later the figure was 519,978, and by March, 1943, it had reached 553,763 horse-power. This has been further stepped up during the past year.

Demands for' Government development of the power resources of the Dominion had their outcome in the passing of the Aid to Water-Power Works Act in 1910, and the Lake Coleridge scheme for the supply of electricity to Christchurch city and the Canterbury provincial district was selected for development. Operations on these works occupied four years, from 1911 to 1915, although the capacity of the plant was substantially increased in 1926 and again in 1930.

With the Lake Coleridge scheme successfully launched, there was now drawn up a complete system of interconnected power installations in both the North and South Islands. Most New Zealanders are familiar with the generating stations at Arapuni, Horahora, Mangahao, Waikaremoana, Lake Coleridge, Waitaki, and elsewhere, and it is interesting to follow their progress since the Government’s plans began to take shape.

In the South Island, with the Lake Coleridge scheme completed and in operation, the Waitaki River was selected as the next (source of power, the .scheme established there, commencing operations at the end of 1934. The scheme at present embraces four units, with provision .for the addition of a fifth. To ensure an adequate supply of water to the Waitaki station in the winter months the raising of the

level of Lake Tckapo has been undertaken, as well as measures to control the outflow from the- lake. A new generating station at the lake is being incorporated in the control works, but work on both the lake control and the unit has been interrupted.

The surplus water available in the winter months in the Rangitata irrigation race has been tapped with the installation of a single unit at Highbank. A rather smaller generating station on the Cobb River, the construction of which has been undertaken by a private enterprise, was acquired and completed by the Government, the power from this plant becoming available to the Nelson district in May of last year. Service to the Marlborough district is beingcatered for by the erection of a transmission line connecting with the Cobb River Station, which is being enlarged.

A grid 'system was established in 1939 by which the generating plant at Kaimata, on the Arnold River (formerly owned by the Grey Electric Power Board) and the station at Lake Monowai (taken over in 1936 from the Southland Electric Power Beard) were linked with the Coleridge -Wai taki scheme, already interconnected. The Dunedin City Council’s hydro-station at Waipori is also linked with the system, enabling power to -be supplied to or drawn from this station if required, and the Cobb River station, too, will be connected up.

So much for the South Island.. The four stations in the North Island — ricrahora, Arapuni, Mangahao, and Waikaremoana been linked up in a grid system to which are connected all the larger generating stations operated by supply authorities. The pioneering installation in the North Island, that at Horahora, was 1 acquired »by the State from the Waihi s Gold-mining Company in 1919 and its 1 capacity extended in 1925. Arapuni, ' which was eventually to meet the

requirements of the whole Auckland district, was begun in 1925, and the first unit was brought into operation in .Tune, 1929, the station being linked up with Horahora. The development of the station has continued steadily until today six units are in operation, with two more provided for under the major scheme.

In 1-922, work was begun on the major generating station at Mangahao. Power was turned on from this unit three years later, following which the first stage of the development of the middle (or Tuai) station at Waikaremoana was put in hand. At the end of 1929 this station was in operation, a third unit being added ten years later, at which time, also, the construction began of the lower station

at Piripaua. Power is now being drawn from this installation. aikai * _ moana's role in the North Island network will be jumped up still further when the upper development at Kaitawa is in operation.

But attention has by no means been centred entirely upon the extension ctf existing, facilities. With foity main stations and! forty-seven standby plants already under its wing, the Public Works Department at present has in hand the construction of another large station at Karapiro, on the Waikato River, which, when completed, will greatly relieve the pressure on the existing generating plants throughout the North Island. The first of the three units, it is hoped, will be supplying power by June of next year, and to this end the powerhouse. transformer house, and dam are being pushed ahead as rapidly as possible. An interesting feature of this project is. that its development will involve the submerging of the site of the present station at Horahora. .

Nor does it end there. • Karapiro forms part of a long-range plan for the expansion of the North Island electric power system approved by the Government two, years ago. and under this plan several large power stations on the Waikato River are envisaged. Practically the whole of the fall in the Waikato River from Lake Taupo to Cambridge will be harnessed by the development of a chain of ten large stations, including Arapuni. Four new stations are to be constructed within the next seven or eight years, and for the entire ten-year plan the sum of 000,000 has been allocated.

With Karapiro well on the read to completion, preliminary work has begun on a new station at'Maraetai. The site chosen is about twenty miles up-river from Arapuni, and with five

main generating units, having a capa city of ISO,OOO kilowatts, it will be the largest so far planned in New Zealand. A ’ 220,000-ivolt transmission line will convey the power north to Otahuhu. and another south to Bunnyth At each of these terminal points a large sub-station is to be built to feed the power into the existing 110,000-volt network. Whakamaru has been selected as the site for the next station, with another planned at Ohakuri.

Unlike the North Island, the South Island has not had to face an acute shortage of electric power. Nevertheless, an eye is being kept on the possibilities of reproductive work to fit into New Zealand’s national plan of activity, and more than one Ministerial hint has been given of the directions in which future .development may extend. While no definite plans have yet taken shape, there have been preliminary investigations into 'the possibility of launching another immense project- a power station on the Clutha River which, with an estimated capacity of 180,000 kilowatts, will, like Maraetai, dwarf Arapuni (SO,OOO kilowatts) at present the largest station in New Zealand. The suggested site of the dam for this station is about twenty miles downstream from Alexandra. . As yet, however, this project has not reached the blueprint stage, and in the meantime all efforts are being concentrated on the development of the North Island supply.

The .fact never the remains that there is an abundance of water-power in the South Island as yet untouched, and one estimate even goes so far as to place its potential horse-power at six times- that available in the North Island. Significantly, in the Government's ten-year plan an amount of L 10,000,000 has been earmarked for extensions to the South Island system.