Water Power and Electricity.

Progress, Volume VI, Issue 2, 1 December 1910, Page 473

Water Power and Electricity.

t Electric Water Power of the Dominion. Electro-chemical Industries. (From the report of Mr. Birks.) The introduction of cheap electric power will open up possibilities in the direction of electro-chemical industries which can only be realised by considering what has been done in other countries under similar circumstances. For instance, in Norway and Sweden nearly 1,000,000 electric horse-power has been installed,'the greater part of which is used for the manufacture of nitrate fertilizers, calcium-carbide, and for iron-smelting. As this industry is not more than a few years old, and as the circumstances for its development are generally as favourable .in New Zealand as elsewhere, it is impossible to foretell what its future may be here; but every water-power development must be made with the possibility of its full power-capacity being required in the early future for such industries. Small electro-chemical factories will be quite worth establishing at once in connection with each power scheme, with the object of utilizing the power at periods of light load, and thus raising the load-factor up to 80 or 90 per cent. . This power could, of course, be used without increasing the operating costs at all, and might therefore be debited at a very low figure indeed, quite apart from the cost of operation say, £2 per horse-power per annum at the power-station, and £4 per horse-power per annum at the seacoast. These prices could, in the meanwhile, only be quoted for a comparatively small plant of, say, 3,000 to 5,000 horse-power capacity, on condition the current were cut off for four to eight hours per day, when the more remunerative load is at its maximum. Apart from the establishment of comparatively small electro-chemical factories with the object of raising the load-factor of a general power-station, it is only a matter of a few years before electrochemical works supplied . from special hydro-electric power-stations will be remunerative on a large scale., in New Zealand. The main industries of this nature which have been developed hitherto are the manufacture of nitrate fertilizers (including nitrolim or calcium-cyanamide), - calcium-carbide (for the production of acetylene gas), carborundum (to take the place of emery), and also for aluminium and iron smelting. In his famous address before the British ■v Association for the Advancement of Science in 1898, Sir 'William Crookes calculated how long the existing supplies of nitrates in the soil would last in the wheatproducing countries; and the results were very striking, emphasizing the necessity for systematic fertilization on an extensive scale, if we are to continue , our present dietary. The most important element to be supplied is combined nitrogen in the form of nitrates and, apart from the quantities contained in decaying vegetable

matter, coal-gas by-products, and mineral nitrate-beds, the main source of nitrogen in the future will be from the atmosphere, and the only means of fixation to render it serviceable for agricultural purposes is by means of electric power. Already enormous installations have been erected, particularly in Norway, for this purpose. The Anilin Soda Company, for instance, will shortly have 400,000 horse-power in operation in Scandinavia for this purpose, and will be manufacturing 100,000 tons of nitrates per annum. In addition to the demand without our own Dominion, which is not yet very large, it will be possible to open up very large markets for these fertilisers in Australia. The manufacture of calcium-carbide will also form an important outlet for electric power. The imports of this material into New Zealand, and value, for the past three years have been as follows: — Year. Quantity Value. Tons. £ 1907 898 14,826 1908 . . . . .. 932 14,966 1909 .' 1,667 22,603 And the demand will no doubt grow more rapidly in the future. The market in Australia will probably be four or five times that in New Zealand. Being classed as a dangerous material by the shipping companies, the freight from Europe is very heavy, and this will give a natural protection which, with the cheap waterpower available, should make the industry very remunerative in the Dominion. Such industries have resulted in other lands in building up whole cities, as at Niagara (U.S.A.), Rheinfelden (Switzerland), Nottoden and Odda (Norway). Probably the Odda works, established by an English company—the Albion United Carbide factoryat Sondre Fiord, in Norway, is one of the best examples of the growth of such a city. The spot has no attractions whatever as a manufacturing centrein fact, it is inaccessible, distant from the markets, hemmed in by mountains, the surface is sterile, and a couple of years ago the valley was practically uninhabited. It has now enormous carbide-factories and nitrate-factories, around which a large town, almost a city, has already grown up, owing entirely to the existence of some 80,000 . horse-power in the immediate neighbourhood. Of this, 23,000 horsepower has been utilized and is now used, producing 32,000 tons of carbide and 12,500 tons of nitrate fertilizer per annum. Probably of still greater importance to New Zealand is the possibility of electric smelting of iron and steel, as we are fortunate in having iron-deposits and the necessary limestone flux within easy distance of extensive water-power. The electric ironsmelting furnace at Tumios, Ohristiania, is now producing iron at £3 per ton to compare with the best Swedish charcoal iron, which costs £5 per ton, and their plant is being largely increased. At Trolhatten and Donnarfvet, steel is being smelted at a cost : of under £5 per ton, to compare in grade with steel previously costing £lO per

ton, and the British Consul at Stockholm reports that "the economic problem of dealing with iron-ore by the electric furnace to supersede the blast furnace is definitely solved." In Savoy 10,000 tons of high-class special steels are now produced by means of electric furnace per annum, worth £360,000, and the business is rapidly growing. : These developments indicate possibilities far beyond anything dealt with in this report, but which must be kept carefully in view in the immediate development of our water powers. In considering the whole question, it should be noted that each average horsepower per annum of steam-power consumes about 10 tons of coal. , This, if sold for shipping or other purposes outside the Dominion, would bring in a revenue of from £3 to £4 per annum, which is at present lost, and, while the same power is available from our water-powers, is wasted as far as any permanent increase in the wealth of the Dominion is concerned. Professor Stillwell, President of the American Institute of Electrical Engi- • neers, in discussing hydro-electric plants, states that "true conservation demands the most prompt possible utilisation of our water-powers consistent with a due regard for the rights of the people as a whole in this property, which belongs to them, and should be safeguarded in their interests." In the same discussion Mr. Deane points out that "every undeveloped water-power represents a constant source of unnecessary fuel-consumption. The mild language used in stating the importance of the speedy development of our waterpower as a means of conserving our national resources is entirely inadequate. Nitrogen is the most important element in maintaining the fertility of the soil, and we largely depend on the nitrogen in our coal for our present supply from the gasworks. The nitrogen of the coal burned in steam-boilers is entirely wasted; and, in addition, the spare water-power may be. used for the manufacture of nitrogenous fertilisers." The Hutt Scheme. ; (Beport of Mr. Birks.) . ■■ The headworks for a final development of 17,000 horse-power, including dam, conduit, tail-race, buildings, and minor en-gineering-works, are estimated by ;' the late Mr. Hay at £286,000. In view of the demand immediately in sight— maximum of 9150 kilowatts: (12,200 horse-power.), with an average load of 3416 kilowatts (4600 horse-power) power available in the Hutt scheme would be ample for. many years to come. The average flow, necessary to supply this load, allowing for all losses, is only i 536 cubic feet per second. To deal with this demand I would recommend the installation of four gener-, ating-sets, each of 2500 kilowatts capacity; giving a total power-house capacity; of 13,300 horse-power. The details of i the power-house plant would be very similar to those proposed for the Lake Coleridge

scheme, with the exception that the head of water on the.Pelton wheels would be only 285 ft., as compared with 470 ft. at Lake Coleridge; and the voltage of transmission, owing to the shorter distance, need not be higher than 35,000 volts, as compared with 45,000 or higher proposed for Lake Coleridge. As in the case of Lake Coleridge power-station, there would be ample spare plant until the third year of operation when the question of adding a fifth unit would require consideration if it is found necessary to have a spare unit in reserve under all conditions of load. It is quite possible that if one machine were out of action the overload capacity of the other three would supply all the reserve power necessary. - The transmission-line would be in duplicate, following different routes as far as possible, in order to insure continuity of supply. The two main circuits would terminate in substations, one at Petone and the other at Thorndon. The circuit to the former, sixteen miles in length, would have a normal capacity of 5000 kilowatts, and to the latter of 6000 kilowatts. In addition, a high-tension connecting line of 5000 kilowatts capacity would be run between the two stations, so that the service to both stations could be carried on without interruption if it were necessary to cut out either transmissionline for repairs. Each line would have ample overload capacity. The weight of copper in the 5000-kilowatt line would be 40 tons, and the full-load loss in transmission and transformation under 12 per cent. The weight of copper in the 6,000kilowatt line would be 56 tons, and the full-load losses, including transformation, under 10 per cent. At the substations the pressure would be reduced to 2200 volts, three-phase, for distribution. Owing to the closely concentrated nature of the load, this would be quite high enough for the primary distribution, the majority of the power being disposed of within a mile of the substations, and the whole of it within five miles. From the Petone substation high-tension distributors would be run to the various factories in the neighbourhood, to trans-former-huts for distribution for electric lighting and power purposes, and to the present pump-stations and the proposed tramway-station. Prom the Thorndon substation mains would be run to the municipal tramway and electric-light station, harbour power-station, pumpingstations, the various factories and mills taking power in bulk, and to transformerhuts for any areas not already included in the city-supply distributing system. The total length of such distributing-mains would be much less than in the Christchurch neighbourhood, but a considerable portion in the city would have t( run underground, involving considerably higher outlay. I estimate the length oi the distributing-mains from the Peton< substation at ten miles of overhead work and from the Thorndon substation ai twenty-seven miies oi overhead circuit: and four miles of underground circuits As the secondary or low-tension distribu tion is already well provided for in tin Wellington district, I have not included i in the estimates. The total capital cost of this system complete, for 10,000 kilowatts or 13,30 i

horse-power, would thus be £443,960 —that is, £44.4 per kilowatt, or £33.4 per horsepower, made up as follows: Per Kilowatt, ?er Horse Total for 10,000 JS 0 f ° l e Kilowatts 13 »; se power . . - _ , Headworks ... 286,000 286 21'5 Power-house plant ... 94,500 9"5 7"2 Transmission line ... 17,160 1"7 I'3 Substations ... 18,800 1"9 I'4 Distribution ... 27,500 2'7 2'o Compared with the cost of similar works elsewhere, these figures show normal capital costs, allowing for the extra cost of freight and labour in New Zealand, except under the item of Headworks, £286,000. This is high on account of the large dam involved; but without an opportunity of going into details of Mr. Hay's estimates I am unable to check it. It works out for the proposed development at £28.6 per kilowatt, or £21.5 per horse-power—about four times as high as for the Lake Coleridge scheme, and three times the general average for such plants. But it must be remembered that it provides for an ultimate extension of the power plant to 17,000 horse-power, when it would work out at only £16.8 per horsepower. Mr. Hay estimated a possible reduction of £36,000 in this item if the plant were designed for a continuous output of 8,500 horse-power, and probably a considerable amount of this saving could be effected in providing for the estimated requirements of 13,300 horse-power maximum, with an average of only 4,600 horsepower. This can only be determined by a detailed survey. It would also be possible to reduce the outlay for the first two years of operation by omitting one of the main generating units, thus reducing the capital cost by £17,000, and one of the transmission lines with its transformers, reducing the outlay by an additional £17,000. Lake Coleridge: Christchurch. (Mr. Holmes ' - Report.) The Lake Coleridge power scheme is, next to the Te Eeinga scheme, in Hawke Bay, probably the easiest to deal with, and but for the necessity of diverting water from the Acheron and Harper Eivers into the lake, would be simplicity itself. The works required consist of a tunnel from the lake through a ridge some 70 chains in length to the head of the usual steel pressure-pipe leading to the powerstation. At the lake end of the tunnel are required the usual head-works and regu-lating-sluices, and at the other end of the tunnel would be required the usual spillway or surge-pipe, according to whether the tunnel is subjected to water-pressure or not. The power-station would be situated on the left bank of the Rakaia River, and would be of simple construction. In order to generate sufficient current to deliver a maximum demand load of 10,000 to 15,000 horse-power in Christchurch, it will be necessary to divert a portion of the flow of the Acheron and Harper Rivers into the lake, otherwise only a little over 2,000 horse-power can be obtained. The works required to effect

this will be low weirs of simple and inexpensive construction across each of the rivers, and short lengths of race. It will not he advisable to divert the whole of the flow of these rivers into the lake, as by so doing the shingle and silt would also be diverted, which can be avoided by allowing high floods and the shingle to pass over the weirs. The level of the draw-off from the lake would be situated at a suitable depth £ below the present surface of the water in i' order that the lake may be used as a storage reservoir to deal with fluctuating demands for water and with the fluctuating rainfall, in such a way that a maximum demand of about 30,000 horse-power may be provided without having recourse to the construction of a dam across the outlet. The information in hand has enabled the cost to be very closely estimated, and in doing so the dimensions of the outlet have been calculated to provide for the delivery of a maximum demand of between 25,000 and 30,000 horse-power in Christchurch, so that at little extra capital cost the scheme may be extended from time to time as may be found necessary. The following is an estimate of the cost on the above basis: Headworks and tunnel .. .. £G5,000 , Diversion, Acheron River . . 7,000 Diversion, Harper River . . . . 39,000 Pressure-pipeline .. .. . . 36,000 Power-station and equipment . . 120,000 Buildings 10,000 Transmission-line .. . . . . 84,000 Substation 25,000 Contingencies .. .. . . 35,000 Total £421,000 The distance from the power-station to Christchurch along the route of the trans-mission-line is approximately seventy miles, which is more than double the length of the "Waipori-Dunedin transmis-sion-line, at present the longest in the Dominion. The greater length of the transmission-line and the necessity for bringing in water from the Acheron and Harper Eivers place this scheme in a rather less favourable position financially than that of the Hutt, although the latter is severely handicapped by the high dam required. The following are the estimated annual costs which must be incurred in connection with the working of the scheme: — £ Interest at 4 per cent. . . 16,840 Sinking fund, 1 per cent .. 4,210 Maintenance .. . . 6,000 Running-costs .. .. .. 7,450 Depreciation .. .. .. 10,000 Total .. ... .. .. £44,500 This scheme is not in such a favourable position as regards the financial results as the Hutt, owing to the absence of so large an immediate demand, as the Christchurch tramways do not require anything like the quantity of current which the Auckland or Wellington tramways require, and at the present time the electric lighting of - p •Christchurch is in quite an embryonic stage. There is, however, one favourable position, in that the City on oil of Christchurch has not yet constructed a large generating-station for electric lighting, so that the current would be disposed of to better advantage owing to the absence of permanent charges on existing plant having to be met.