THE VALUE OF ELECTRICITY

Pukekohe & Waiuku Times, Volume 9, Issue 519, 1 April 1920, Page 3

THE VALUE OF ELECTRICITY

I CHEAPEST AND BEST POWER t LAKE COLERIDGE WORKS COMPREHENSIVE SURVEYI^ (By Mr. L. Birks, BSc;, M. Inst,, icfe.). By courtesy of the Public Works Departn if ntjlt he /Times" is In receipt of a valuable and highly infornfttiJl beskltf describing the Lake Coleridge hydro-electric power jAmi, thfefies to which the power is put, and the cost of thejmme to aWsumers. We will not trouble our readers with jfcfil/technieal fitter that can >e understood by experts only, bul we give hereun&r a summary >f the benefits conferred on the pefple of the immense area served >y this jJfceer of large stations in' New Zealand. The alfflor of the bolklet is Mr. L. Birks, RSo., M Inst.. C.E.. M.I.E.E, «| f 1* -«TOIRISTCHURCH CITY.

V P° or Mail's Power. The immetfiat<Vcffeet of the introduction of hydro-electric power wjlTto sJErikinjkreduction in the council's retail and wholesale JnargesjfoJ The average charge for light was reduced *' om s i£Br d ' and f°V> ower from 2 M'd to Id; and the wholesale power/Fajß: down to %<nfor ordinary day-work and l-6d for nightworjsf T» demand within the city has gone up from about 700 kw. to ■%jßr lc\C, and is still increasing rapidly. At the end of the last nnancAl year there were 6124 consumers connected to the city mains, aiJI the connected load amounted to 12,685 kw—that is, four times the maximum demand at any one time. Thatis to say, the city is able to sell the 3000 kw. which it buys from the Department at least four times over to different con-1 ■imers during the day. - illustration of the fact that electricity is the "poor man's light," 33 per cent, of tthe above consumers pay less than 4s per month, and 40 per cent. less tthan 5s per month. The working cost per unit sold has fallen from 2Hd to Id, and the total costs, including capital charges, from to 1 3-4 d, and the average selling price from 3 3-4 d to below 2d per unit, and the demand has increased by leaps and bounds. Dairies and Suiter Factories. The whole of the dairies and butter factories within reach of the mains are now supplied, in snite of the necessity of keeping steam in most cases for scalding, washfng, and pasteurizing. For separating and churning the steadiness and uniformity of speed are of great advantage as compared with tthe steam engine. For mUkjng Machines the ease of starting and stopping, and the unattended operation of the motors, as well as the cheapness of the power as compared with petrol or kerosene fuel, determine the-'mflttera without question, and are making quite a revolution ■>i dairying wherever the mains are accessible. The Tai Tapu Dairy Company has not only taken a supply [for operating its butter factory-nt Tai Tapu, but has installed a complete reticulation throughout the area occupied by its milk 'suppliers. The resulting stimulus to the industry is already t marked. When a farmer wants to select a site to settle down, the convenience, economy and comfort of an electric supply are decided factors. , Quarries and Brickyards. Two large quarries, two large brickyards, and one pottery ate now driven by Lake Coleridge power. In these cases the large Bstantaneous overload capacity of the electric motor is of the Trtraost value. It is found in nearly every case that the former engines are very much overpowered for their average work, owing to tin- necessity of their carving an occasional momentary overload without pulling up, which the electric motor does without difficulty. ' 4. • Retail Domestic Supply. -•■ The retail supply is'as far as possible in the suburban and country areas handed over, as in the city, to the local authorities, and arrangements have already been entered into with those set out in the attached table. The retail rates in these districts are in most cases based on the Public Works Department's retail scale. Three of them—viz.,' Waimairi County and Riccarton and Spreydon Boroughs—purchased their energy in bulk through the City Council. The others are supplied from the Department's mains, with an arrangement under which the Department and the local authority share the gross revenue, the local authority undertaking tthe complete installation, control, maintenance, and management of the reticulation in return for their share of the revenue, and the Department simply supplying the necessary power in bulk. In these cases the Department installs and maintains the necessary substation to reduce the pressure from 10,500 volts to 230 volts for retail distribution. These are usually small—lo kw to 50 kw capacity—and for this purpose a cheap type of outdoor pole substation has been developed. For temporary service or for emergency supply pending the installation of a permanent substation a portable van has been equipped with a 50 kw transformer and high and low tension switch gear, and has proved of the utmost value.

Economy of Coal in Canterbury. A very important aspect of tthis subject is the economy of coal used in Canterbury as the result of the operation of the Lake Coleridge plant. The coal consumption in the most efficient and well-designed steam plant in Canterbury—the tramway power station—for the last complete year of coal firing was about 8800 tons to generate 5,179,457 units, with a normal maximum of power year, working on a load factor of about-50 per cent. The ordinary small commercial steam plant consumes from three to five times as much coal as this, though the load factor is low - usually only 10 per cent, to 20 per cent. The owner does not, us a rule, realize how much coal per actual horse-power hour it is using. We find in practice that the actual average power used in small factories is usually one-half to one-quarter of what the owner estimates, the estimates being usually based on maximum ratheu than on average power. The average small power plant on a 15 to 20 per cent, load factor usually uses G to 8 tons of coal per horse-power per annum. And thus the Lake Coleridge plant, replacing such plants and working up to 50 or GO per cent, load factor, saves 15 to 25 tons of coal per annum per horse-power of its useful output.

Road Transport. 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 and explosion and explosive machine the production of power is violently intermittent and irregulaii. 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 the battery is the smoothest, steadiest, and most silent form of poweti 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 proportionately low. It takes live 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 motor spirits, for which we have to pledge our credit to a foreign nation to the amount of 2s (id for every gallon consumed. The problem of economy in the domestic delivery of milk, bread, and other commodities is engaging the attention of oui local economists. The ultimate solution of this problem will cer tainly be expressed In tennis of hydro-electric power. i }' Domestic Savings. JVlthougrf Uie ,#liviiig of labour in nmjtti', transport, and fir ing of coal by the use of electi«rfight is very great, it i.in domestic#iff that ipr effecting econoni; and increasing frifcl ifcil the labour cos; per ton ry'Sßnie9tlc'"range Ssimply appalling The cost 6f firing includes, of tours* the cost oWrfftt'clie.s, kintiK' ing, most# of the dusting and clrfning in the o. clinaiy lions . filling thft coal bucket and the coal bin. It involves about <;iv half of the domestic labour in the prdinary household, and pitiably costs £5 to £lO per ton of coal fired. Nor is it expensive to install in the first instance if tli house is built as an electric house; in fact, a complete electri outfit I'oi' lighting, heating, cooking, and washing will cost l,\; • " probably one-half of a similarly complete coal and kerosene out fit, and the labour cost of upkeep is very much less. Industrial Possibilities. The Lake Coleridge scheme will be a financial success thai is to say, it will pay not merely working expenses but ample capital charges and depreciation reserves. But the main object of the scheme is not merely a commercial or financia!*one. It will supply cheaper light and power than any other source, but it wil d< very much more than this, and it has a much wider national significance than any commercial, consideration could give it.

It will open up now industrial possibilities to Canterbury. It will a si rung stimulus to tho effort to become more selfsupporting and more independent of overseas shipping. It will brin:;' possibilities of seicntilie and labour-saving operations within reach of the mining generation which have not been available in tlie past. Social Amenities for the Primary Producer. l!ut from the more important sociological aspect its future is still gToalor. As the lines extend away into the back country it will make the home of {ha primary producer more attractive and iinii<' comfortable. ThenJfr will stimulate production. It will bring hetl-T heal I h phvsicai#monl al, and moral—to thousands of little (lies, wln>.-.e >t: jm ncei iMirked mothers now have all too little time In p'iy ilit'in .£ Bre ihan the barest amount of attention. _i, If ph" filler id.ge system did nothing more than supply -ifrne Jjfcdc ironJfnd one washing machine in every home in Canf,jfirb \yy it wi.iiW' jartijfc a complete installation, perhaps not quite as h ge as one 11n|^Jjpf'fteen put in. but equally complete in evcy way, -jftfiil would pay. f' The Future In Co'.intry Districts. The Jjffure is unlimited. Kvery estimate that is made of the dem doubled and trebled. A new application is developed, and all forecasts are left behind. The electrification of the i ail wa\ s is only one nf numerous outlets. The railways themselves have a Hciil whin every village has its electric service. The telephones have their limit when the.e is an instrument in every house. Hut when electric service is laid on to every house throughout the land the development of electric supply will be only commencing. In the cities the businesses will be shared with the gas companies, but the in-eat future of electric supply lies in the country districts -in the decentralization of our industries and the return of our people from the congestion of tho cities to the healthier life and surroundings of the country.