NZ Journal of Science and Technology
Vol 1. January 1918.
During the Middle Ages the largest source of power in Western Europe was the watermill. The Domesday Book recorded the existence of small water mills at almost 4000 different places in England. Water wheels were the prime source for driving textile machinery in the initial stages of the Industrial Revolution, being continually improved until large and highly efficient machines were made.
For water falling from a height, the only means of utilization was to set up a series of wheels in a cascade. Then from 1740, column of water engines were developed in South Germany and France. These were analogous in performance to the steam engines of the time.
In 1824, Burdin gave an account of an invention he called the high speed turbine. This was a water engine so designed that the loss of energy due to the turbulent impact of water on its blades was reduced to a minimum. Also, the water left the machine without appreciable velocity.
Practicable water turbines were not built until the middle of the nineteenth century, however, and only became really important with the development of electric power. Sir Charles Parsons' steam turbine also derives from Burdin's ideas.
In New Zealand, water power is a very important energy source, providing a major part of our electrical energy. The national water-based electricity supply we have today can be traced back to 1903.
In that year "an overseas expert" from California, L M Hancock, toured the country in the company of P S Hay, the Superintending Engineer of the Public Works Department, and reported on the potential for hydro-electricity development.
With a degree of hyperbole that we might think out of place coming from an engineer, L.M.Hancock was lyrical about the possibilities he saw. He referred to waterpower as white diamonds which would contribute to material wealth in the way black diamonds (coal) had done for England and America.
With this cheap power available, wonders can be accomplished for the colony. It has been found in a good many cases that industries spring up in a locality where there is an abundance of cheap power, and judging from conditions in the colony this will be true of any development you may put in.
Every city, town and hamlet can be furnished not only with power and light, but with heat also. The supplying of power from large systems, where they pass through the small towns, at rates that could not be thought of hitherto, will help in a wonderful way to build them up. Industries that thrive best in small places will be encouraged, the population will be better distributed, and many of the evils of a crowded city avoided. This immense supply will enable each home in the colony to enjoy luxuries that in other countries are enjoyed only by the rich.
The home, where electric cooking, heating and lighting are installed, will be a model of convenience and comfort. The servant question will be nearer a solution, and the drudgery largely done away with. In the factory and shop, electricity will do the work that is now so wearing, and in every department of life applications of it will be used that will bring about material advancement to a wonderful degree.
A H J R 1904
In his general survey, Hancock listed 43 locations and commented on the ability of each to produce power. He also made a detailed cost estimate for development of Lake Coleridge - a location that impressed him very favourably. He referred to the benefits that could come from electric pumping of water for irrigation and discussed the electrification of railways with the proposal that the suburban lines in the main centres and the Christchurch-Lyttelton tunnel should be the first sections of track to converted.
Manapouri - P S Hay
A more detailed report on the country's hydro-electric potential was prepared in 1904 by P S Hay and was presented to Parliament appended to the Public Works Statement. Hay's report as well as being very thorough, was to some degree prophetic. He pointed out that to develop the waters of Te Anau and Lake Manapouri to their full extent, the water from both lakes would have to be diverted into the Sounds. He said,
"It is not likely for scenic reasons that a high dam would be built at Manapouri. The present beauty of the lake is worth preserving to the fullest extent"
and .. "These two schemes will likely remain as reserves until all the smaller schemes are exhausted. It may happen that a great part of the power would be used at the power station in the Sounds, in electro-chemical and electro-metallurgical work. The possession of such enormous possible hydraulic-power schemes at the seashore, with deep-water access, is, as far as I know unique.
This may lead to their utilization, at no very distant date, for industries now non-existent."
A New World in Canterbury
Birks, the author of the quotation at the head of this page, was the Electrical Engineer with the Public Works Department in Christchurch. His description of the developments in Canterbury following the availability of electricity from the Lake Coleridge Power Station and his optimistic view of the future provide an example of the uncomplicated view technologists and others took at that time of new technological development.
The opening of the Lake Coleridge Station was undoubtedly a significant event in the history of Canterbury. It provided cheaper energy for a number of important enterprises. Among the largest consumers of power from the new station were tramways, the freezing works, and the dairies and butter factories. The Christchurch tramway had already been electrified, being fed by power generated in four steam turbines. The switchover to power from Coleridge led to a saving of 2,000 pounds per year in electricity costs.
The Tai Tapu Company not only bought power in bulk for its butter factory but also reticulated its suppliers and consumers within its district. In 1918 they had 76 consumers, including 25 milking machines. In Birks' words "one of the comforts of the city has been carried out to the hardworking dairy-farmer."
Three freezing works - at Islington, Belfast, and Kaiapoi - were supplied initially. The main load was the large motors for the refrigeration machinery. Since this was a seasonal load occurring between December and July it was proposed that in the off-season they should work up "their by-products by electrochemical methods" or use the power in "other electrochemical processes for the manufacture of essential chemicals and manure ingredients", thus broadening the range of activities of the freezing companies.
At this time there appears to have been a fascination with the possibility of electrochemical processes. This was of course finally realised in the 1970s with the startup of the aluminium smelting industry.
Not all the uses of electricity envisaged by Birks in 1918 have yet been realized. He wrote:
"In road transport even greater changes are to come. The petrol-car has certainly reached a high state of development, and is very satisfactory. But it is still an explosion machine and explosive machine: the production of power is violently intermittent and irregular. This reacts on the life of the engine, chassis, body, and tires, and on the comfort of the whole vehicle.
The electric motor operated from a battery is the smoothest, steadiest and most silent form of power possible. The cost of power at present prices is less than one-half of the cost of petrol, and the cost of repairs and maintenance proportionally low. It takes five minutes to learn all there is to learn in driving an electric car, and there is nothing to go wrong.
From the national point of view it consumes only natural power from the mountains instead of petrol, for which we have to pledge our credit to a foreign nation to the amount of 2s.6d. (25 cents) for every gallon consumed.
The petrol-lorry running say fifteen miles to the gallon costs 2d per mile for fuel only. The electric-battery car or lorry is garaged, examined, and charged up every night by the Christchurch City Council at 30 pounds to 60 pounds per year, according to capacity, ranging from 1 ton to 3 tons of load - i.e., from 2s to 4s per day, giving a daily range of sixty miles.
Even if only forty-eight miles per day of this range can be utilized effectively the cost of electricity per mile ton is only 1d. for a 1-ton lorry or car, and up to 1d for a 3-ton a lorry - a very substantial saving compared with petrol. There are about a dozen such vehicles now in use in Christchurch for various purposes, and provision is being made in anticipation of this number increasing to five or six hundred in the near future. The figure shows the City Council, electric-battery lorry for refuse and coal, which is not only propelled but also tipped by electric power.
The problem of economy in the domestic delivery of milk, bread and other commodities is engaging the attention of our local economists. The ultimate solution of this problem will certainly be expressed in terms of hydroelectric power.
Birks - NZ Journal of Science & Technology
Vol 1. January 1918.
Interest in electricity as a transport fuel has been rekindled in recent years with the dramatic rise in the cost of oil and the prospect of further rises; the commercial availability of a battery with the capacity to give an electric vehicle a performance comparable with a conventional car is still awaited.
Birks drew attention to the German use of electricity for steel smelting and noted that hydro-electricity could give New Zealand an opportunity in this respect.
Woman's Labour - Prophecy
Birks concluded his 1918 article with a prophecy which has been fulfilled, saying :
"In the domestic sphere the economies of time, labour, material, and temper, resulting from the general use of hydro-electric power for washing, sweeping, sewing, heating, cooking, pumping and lighting will amount to a revolution in the conditions of woman's labour which is hardly yet conceived."
This revolution has of course extended to more than the conditions of woman's labour, having included women's whole role in society.
Lake Coleridge power station was the first of the State hydro-electricity schemes that came to play an important part in New Zealand's indigenous energy supply.
From the beginning the emphasis was on schemes giving cheap power through economies of scale. In an Interim Report on a North Island Hydro-electric Development Scheme in February 1917, Evan Parry stressed the advantages of scale. "The fundamental principle involved is that of centralizing the power generating plant and concentrating it into a few large units where the energy can be generated to the individual power user,"
He went on to point out how the ability to transmit electricity made the use of a large centralized power plant possible. His report proposed three North Island power sources, Mangahao, Waikaremoana, and Arapuni - all of which were subsequently built.
By 1919 the Lake Coleridge station was starting to make a profit and work was commencing on the investigation and construction of Arapuni and Mangahao. A network of transmission lines to reticulate all main centres and cover most of the North Island was planned.
At this stage there were in both islands 55,000 electricity consumers fed, in the main, from 64 small local plants having a total capacity of 35 megawatts. It was the existence of these consumers that allowed the State to build its large-scale plants in the knowledge that once the cheap power from them was available it would have a market.
The 1919 report by the Chief Electrical Engineer noted that, ultimately, farms would benefit most from electric power and proposed that future developments should be designed to meet farm demands.
With the establishment of a separate Hydro-electric Branch of the Public Works Department with Birks as the Chief Electrical Engineer the annual Statement on Hydro-Electric Power by the Minister of Public Works, J G Coates, contained a eulogy on the benefits of Lake Coleridge to the public of Canterbury and calculated that, by saving the costs of 45,000,tons of coal per year, an annual net benefit of some 200,000 pounds was available to the consumers.
"And apart from the saving, the comfort that has been given in ten thousand homes, the increasing efficiency in dozens of workshops and factories, and the security and reliability of the hydro-electric power supply during the trying period of the railway restrictions and the coal shortage, are advantages of even greater importance to the consumers than the cash saving."
Such was the unhesitating acceptance of the new technology.
Electric Milking Machines
Progress continued in subsequent years. The number of electric milking machines in the country (548) became noteworthy in 1922, as the changeover from other power sources took effect. Internal combustion engines mainly drove the 12,500 powered milking plants in operation at this time though some used water wheels and others a water-operated vacuum pump.
Another noteworthy event was the use of electric motors for the grinding of phosphate rock which was processed to provide a replacement for basic slag as fertilizer. This had become scarce during the war. The phosphate came from the Nauru deposits in which the Government had acquired an interest. Rock phosphate treatment works were established in Auckland, Christchurch, Dunedin and Invercargill by 1922.
The same year saw the establishment of an electric furnace using power supplied from Lake Coleridge. After considerable difficulties, pig iron was successfully converted into steel.
As a basis for planning of the power system it was considered that 0.2 horsepower per head was an ample but not excessive target. (In 1980 installed capacity of 4,000 MW corresponded to about 2 horsepower per head or ten times this.)
Electrochemical Industries - A Fascinating Prospect:
In 1922 the prospect of electrochemical industries continued to have fascination. It was considered
"the main justification for the development of the largest and most economical hydro sources of New Zealand will be the establishment of large electro-chemical industries...there are several sites in New Zealand, particularly on the western fiords of the South Island.... favourably situated for such industries and it is important that these should be surveyed and the results advertised abroad from whence the capital for these industries will come."
In the following year, commenting on future development of hydro-electric power, the Ministry of Public Works, J.G. Coates, stated,
"The development will amply meet the demands and give a margin for attracting special industries depending on a supply of cheap power. The question of large surplus power to attract special export industries by offering cheap electric power is an important one and receiving the fullest consideration.
The Dominion is at present too dependent for its export trade on agricultural produce, the prices of which are liable to serious fluctuations.... It is therefore important that every effort be made to develop an export trade in manufactured goods or chemical or metallurgic products, and in this direction cheap power can assist very largely."
These words might well have been a quote from a member of a number of administrations in the sixty years from 1920.
It is clear that, by the mid-1920s electricity, was an important energy source providing power for a number of key technologies - refrigeration, milking machines, fertilizer manufacture etc.
For most of these examples the importance of hydro-electricity would have been its availability and reliability rather than its cheapness, since, in general, energy costs are only a small fraction of total costs. Aluminum smelting and to some extent steel making and forest product processing are exceptions to this rule but these are more recent developments.
All Electric Homes
Electricity's cheapness was undoubtedly, however, a major reason for the growth of all-electric households in this country, with electricity being used for space heating, water heating, cooking and lighting. Eventually the domestic use of electricity was to grow to such an extent that household consumption became a higher proportion of total consumption than anywhere else in the world.
The growth of the hydro-electricity supply continued with the construction of Karapiro and three stations at Waikaremoana in the North Island, and Waitaki, Highbank, Arnold, Monawai and Waipori in the South. The Cobb station served the isolated Nelson-Marlborough region. In 1950, despite this expansion of the supply the total annual consumption for all New Zealand was still well below 3000 GWh, the quantity of electricity which would have been consumed by the aluminium smelter at Aramoana if it had been built.
New Power Sources to Meet a High Growth Rate Geothermal Power and Nuclear Power
During the 1940's the momentum of growth of electricity supply kept on at a rate of about 10% per year, with the North Island growth being slightly greater than that in the South. By 1948, it seemed certain that the available hydro sources in the North Island would soon become fully developed; attention was diverted to other possible sources and the Department of Scientific and Industrial Research undertook to investigate the possibility of using geothermal steam. This was seen as an attractive option provided economic and technical viability could be proved.
The full range of options was thoroughly canvassed by the State Hydro-electric Department's Chief Engineer, M G Latta, in an important paper published in 1950. Latta looked at eleven ways of providing the additional power requirements in the North including:
Cook Strait transfer of South Island hydro power.
At the time, the supply of coal appeared to be limited and Latta thought that, provided they were technically feasible, geothermal power stations and the transfer of electricity across Cook Strait would be the most economical way of meeting the North Island's needs.
Subsequently, of course, wind power has been successfully utilized in a farm near Palmerston North and the Maui and other fields have supplied natural gas for power station fuel, replacing coal which has proved hard to win economically. This use of gas has obviated the immediate need for nuclear energy.
top Geothermal Power Cook Strait Link