THE WAIPORI SCHEME.

Otago Daily Times, Issue 14156, 7 March 1908, Page 4

THE WAIPORI SCHEME.

THE QUESTION OF RATES.

Bv E. W. Ackland, A.M.Am.I.E.E.

A very interesting report on the Waipori undertaking waa read by the town clerk at the meeting of the City Council held on February 2t>. Although more or, less a repetition of previous accounts many times published, the. report is of value at the prceont stage when everything connected with. Waipori looms so large in the public eye. The torn dork,, however, naturally falls into many errors when dealing with an electrical question, which can only be expected from one who has not had practical experience of the conditions under which electrical power stations are operated. Apart from- this, however, Mr Ridhards refers to matters of construction, in whioh he is (no doubt unintentionally) distinctly incorrect. For instance, lie described the Burning which now stands as being capable of.dealing with only 2000 horse-power, As a matter of. fact the fluming was designed for 4000 horse-power, and is fully capable of carrying water for that power. Ho ak>o omits to mention that the transmission lines to Halfway Bush, and from there to the converter station (both erected), are likewise designed, for the larger power. All that will be necessary when the demand justifies increasing the plant arc' an ; extra pipe lino and the necessary new units at Waipori and Halfway Bush.. The cost of erecting the new plant will not "be anything like so costly as was the erection of the present one, for the reason that there are now facilities in the way of better roads, tools, plant, etc., which did not formerly exist.

SHORTAGE OF WATER. It is, of course, unfortunato, that the water supply has been so disappointing. I 'do not think, however, that tho council can claim to have been deceived as regards the normal flow from the Waipori River. It is universally admitted that such dry seasons as we have, had for the past two years have not been experienced for 40 years. One can only base calculations as to power from a river on its previous and the past history of Waipori. for the timo mentioned showed an ample flow. Tho shortage of these two years has, however, proved a blessing in disguise, for it is now possible to say what power can be obtained from the /natural flow of the river at its worst, and to furnish provision for such storage as will make good any shortages. The writer recently paid ,a visit to Waipori, and was shown the proposed dam site and storage area. If councillors and those interested would only visit the spot they would appreciate the wonderful way in which Nature has already provided tho reservoir. Very little, expense is required to dam the river, and the risk of flooding the plains below is remote in the extreme —in fact, it cannot be said to exist at all. Mr Stark stated that the. reservoir would store sufficient water to keep a complote ■plant of 2000 horse-power in operation for 100 days, even if the Waipori River ceased to run at all for that period. Such a storage, should be sufficient to calm; all fears as to whether it is possible to make tho flow of water as plentiful as was originally anticipated. INTERRUPTIONS IN THE SERVICE. Owing to garbled reports which have crept into the press from' time to time as to tho cause of 1 tho stoppages which occurred at the initiation of the Waipori service, much uneasiness has been caused to prospective power consumers. Such stoppages were only what might be expected until the plant was got into smooth running order and tho staff properly trained, and aro incidental to any new service. , Those establishments, however, which were sufficiently enterprising to avail themselves of the power are high in their praiso of the splendid service and smooth running of electric motors as compared with other sources of power. POWER RATES!

In dealing with the power rates the town clerk makes the mistake of looking at the Waipori scheme from a. conventional point of view, 1 which does not apply to tho Dunedin system. It must be remembered that we obtain our power from,water, and, therefore, in dealing with tho question, of rates it is incorrect to baso any calculations on the charges ordinarily levied by electrical stations elsewhere, which derive their power from coal and steam. There is no similar undertaking in England or Australasia, (except Launoeston, whioh is- too small to count) with which to compare our system. Thero remains ouly America, and conditions are so different thero that comparisons are useless. Waipori stands alono in Australasia, and must be considered from an impartial and broad standpoint. The rates for power in any station must be fixed by the nature of tho load curve. During certain hours of the day—say from 3 to 7 p.m.—there is a great, demand for current, and high rates should be charged accordingly. From midnight until, say, 3 p.m. next day there is very little demand for current for lighting purposes; consequently, in order to make the undertaking profitable- it is necessary to fix such low rates as will tempt consumers of power to adopt electricity in preference to steam or gas. If the rates are fixed 60 high that consumers will not buy in bulk during slack hours, then it, follows that an expensive plant must be idle or be inadequately employed, although engineers and assistants will reguire to bo at their posts jiist tho same. If possible, it i 6 well in electrical' stations to make peak load consumers pay

the working expenses, whilst power consumers during slack hours provide ilio profits. Now, tho chaiges leviable for power (hiring the slack hours naturally depend to a great- extent upon the eost of generation. A'.y revenue h better iJian none, since, as before stated, the statf has to lw provided, and plant, capable of dealing with peak loads has to be installed. Tim amount, of wear and tear on a modern plant, is very small—it is the question of fuel which fixes the rates. With the old tramway steam plant, the cost of generation was about Id per unit. Coqj and wafer alone cost about .8 penny per unit. It follows, therefore, that with a steam plant the minimum price for current must bo based on the cost of fuel, otherwise the plant, would run at a loss. If coal and city water cost .8 penny per unit, then for every unit sent out at least .8 penny should be charged or the plant might mora profitably be allowed to stand idle. Current cannot, under tlio circumstances bo generated without coat, _ since every unit supplied represents a. certain definite amount of coal and water. It should bo mentioned hero lliafc .8 penny is a very Jtigli fuel cost. It was caused through tho violently fluctuating tramway loadi, experienced at tho power station, which, are far more expensive to cope with than the steady louding of, sav, a flourmill, which may not cost, onehalf.

Now, take tho ease of Waipori, and note the difference. (Jranted an adequate 6iipply of water, the How through the ihiming or by the natural course of the river continues whether the, power contained l therein is availed or not. At Waipori there are automatic governors which cause jets of water to strike the buckets of the Pclton wheels or to deflect into the exhaust pipe according to whether tho load is light or heavy. If the load should go off altogether, then practically the whole water is wasted, only sufficient striking tho buckets to keep the wheels in motion and yet tho operating expenses remain tho same. The price of .power from Waipori is therefore not governed by,the cost of.fuel, this after initial expenditure being provided frco. by Nature. Neither can it be governed by tho wages of the operating staff, who must ho present' in any case. It shouid be GOVKRNKI) FIJHKLY BY THE 008T OF COM-r-ETING POWERS, SUCH AS STKAIt Oil OAS, since every unit sold for power during "slack" hours, at- wliatovor rate obtained, represent income whicli would otherwise bo lost. The* question then arises as to the cost of these \ competing powers. 'Sir [ar as gas is concerned tho rates for electrical Aower might be.raised above tho present standard and yet compare favourably, and, since the corporation-owns tho gasworks, rates for each might bo arranged so that neither would be favoured. It is unfortunately not «'as, however, but steam which has to be feared, Tho town clerk states that he con-, eiders the minimum rat© for power should bo Id per: unit, fiad the council adopted such a rale for the contracts already let. it is a certainty _ that they would never have been entered, into by tho consumers. With the exception of the Miiburn Lime and Cement Company, whose contract was signed' in defiance of tho past electrical engineer's recommendations and the present engineer's protest, all the bargains made by the city for electrical power have-been on, a fair and just basis. With the exception mentioned, a rate of about onc-thirdi of a penny i 6 charged to consumers of over 25 h.p., provided they confine their supply to the period of low' demand, and. a jat© five times as high if they draw their power during "peak"--loading; The latter handicap should be 'sufficient : to encourage consumers to be as economical as possible during theie "peak"' hours, and if it does not have this effect it should be raised, since current between 3 p:m. and 7 p.m. is in strong mand and therefore valuable.

' One must hot, of course, overlook tin question of the cost of distribution, but the same ■ mains ; which supply current to consumers at .high rates during peak loading hours are usually;, available for other consumers who only draw their power duriug' slack hours. ' In- any case, the interest on the cost of- special powor distribution mains, when divided by the number of units sold, represents a .very minute figure-.

I have mentioned already that the cost of steam power governs the price at which electricity should bo sold from Waipori. In proof of the statement that the 1 power rates at present 1 offered, by the corporation are not unduly low, it maybe stated^ that tho writer was employed recently in a Consulting capacity by two power users, and in each cose-had to advise adherence to steam power, since no economy couM be offecfed by, the'installation of motors if operated by electricity at the rates quoted.

DEPRECIATION. '. It is not my purpose to enter into the matter of depreciation except to point out that the question of rates'for power purposes for supply during slack hours should not be affected by depreciation. ( It must be dearly understood that I am dealing with power rates only, not lighting rates. The depreciation of the value of the fluming, turbines, generators, transformers, switchboards, and poles is practically unaffected in a water-power scheme, whether the plant is lightly or heavily, loaded; Tho same cannot be said of eteam-opcratod electrical plant. Inter alia, I might remark that Mr Richards is mistaken in roferringi to the plant at Waipori as being of a "delicate nature. On the contrary,- it is exceedingly rugged And almost "foolproof-far'mbro so than a steam or gas driven plant.

PROPOSED PRODUCER GAS PLANT. It has been pointed out that fluming and transmission lines have been built to deal with a. plant of 4000 horsepowor. Surely the council will not seriously consider throwing this expenditure ,on to tho ; same sorapheap ■as the Lee Stream works. Apart altogether ■■ from this, it appears to have been forgotten that a 800 horse-power etcam plant already stands at the converter station,' Cumberland street, quite capable of'dealing with the tramway load under normal conditions. Producer gas' is about the last source of power to bo adopted where-violently flue-, toting loading is to be looked for. It is high in firat' cost and unsatisfactory in operation unless a steady load can ho assured. With steady loading there is probably no cheaper power to bo fofarid, except "water. Steady loading, however, never oxists in an electric power station. The City of Johannesburg tried producer gas on a largo scale for its electrical plant, with disastrous results, by .which we .may profit. , . WILL WAIPORI PAY?

Tho statement is mad© with weaflsome reiteration that Waipori will never pay. Upon what grounds does this assertion lie? Because tho scheme has shown a loss of £5000 in the first'year? Surely it was never expected that the whole output of the plant would bo taken up in a year. Compared with othor places, Dunedin has shown a stronger early demand than is_ usually experienced from a city of its size, and, my opinion, has dono remarkably well for its first year. It has to be remembered that an electrical . undertaking is far removed from an ordinary business enterprise!. A firm or company starting a new business liegins with a small' staff and gradually increases it as the turnover justifies. With Waipori the ' operating expenses will be practically the same' the fourth year as they were the'first, second, and third. The interest duo to increased capital expenditure will of course increase, but the total generated cost including all charges should show a declining rate per unit. This statement is more particularly applicable to a water power plant than to a steam or gas-driven one. As before shown,., increased output with a fteam .plant means more coal and

city water (or more eoko or anthracite con) for a gas product? plant), whereas with Waipori the flow of wato'r remains, the same whatever the output, up to tho limit of tho power available. ' ' . ' "

SUMMARY. : , ,1 trust that wJiat I have 6tatod is sufficient to prove:— Ist. That (ho -disadvantages of Waipori iMivo hecn exaggerated, and are easily and economically remediable. 2nd. That tho present power rates are not too low. 3rd. That, any increased power should be derived by. water storage at Waipori, anw f , rom " n '"dependent- source. 4th. that the very last plant councillors should adopt for increasing their supply (ev.y.i supposing they mistakenly decide agains extending tho Waipori scheme) is a producer gas plajit, , . ':■,■■