CITY POWER PLANT

Evening Post, Volume XCIX, Issue 115, 15 May 1920, Page 9

CITY POWER PLANT

TO 188 KDITOE. Sir, —A number of arguments have appeared in the Evening Post in connection with the advisability of removing the present power plants to some point outside the city. " Engineer " and "Power" have advocated scrapping all the pre- ' sent plant, and installing at, say, Kai- ■ warra a station equipped with more up-to-date machinery.

I would like to add the few following comments against such a proposal, and to give your readers the benefit of my experience on such matters. " Engineer's " arguments are parochial, and he calls my policy "go slow," because I am farseeing enough to suggest a policy which will provide electricity for the whole of the North Island, and not only our. own little burg, which owing to its situation is not likely to become a great manufacturing centre.

Mr. Parry, in his 1918. report, deplores the fact that our population drifts to the towns, and states that the general use of electricity will stimulate a movement in the opposite direction, and closer set tlement will result. This closer settlement will mean wealth to New Zealand, 1 a-nd, incidentally, to Wellington. To say that there is insufficient hydro-power is absurd. Mr. Parry informs us that a sub-station load of 130,000 h.p. can be easily had, and will meet our requirements, and a return of £5 9s per h.p. will meet expenses. .These figures are based on pre-war charges, although as the report is dated 1918, ho doubt present prices are somewhat higher. Had "Engineer" experienced the coal troubles of the last five years in connection with generation o! electricity, he "would hesitate before rushing into the expense of a large steam plant. His proposal is, however, to Ret over these by building a new station on 1 some site (he mentions' Kaiwarra, though goodness knows Why), and installing more efficient plant. The idea being that the saving in fuel, owing to the use of high-pressure steam, will more than compensate for the extra out-, lay. I would remind him, however, that the capital charges of the present stations would still have to be added to those of the new plant, and I figure that the (Saving would not be sufficient. I have just read of a very large steam station being built in Europe, and the steam pressure is 1701b per square inch. It is evident that high pressure does not appeal to the engineers responsible for this undertaking, and the reason given is that although high-pressure steam shows a saving in coal, this economy is only apparent, owing to the very high maintenance and cost of running. The point is a vital one to us, as we are far from the places where these high efficiency plants are made, and unless N a large amount of spare parts' are kept on hand w©shall be in trouble; a war or a strike might even cripple the plant. "Engineer" refers to load factors'and quotes 50 per cent. ,as being quite a minimum figure. If all his calculations are as misleading, the value of his statements must be discounted. I have before me an English Electrical Journal giving the load factors of 270 English electricity supply concerns; the highest of these is 33 per cent., and the average for the lot is 21 per cent. It is easy to assume that the Wellington load factor will not be very much, better than this, and if it reaches 25 per cent, we may congratulate ourselves. •" By arrangements of tariff we may induce factories to use power during the hours when the demand is least, that is, between midnight and 8 a.m. Each year, however, factory employees, become more disinclined to work while others sleep, and the day is not far distant when special inducement will" have to: be given for night shifts, the benefit therefore of cheap power will be swamped in wages. It has been suggested that, the iocul freezing works •would take power from the city if current could be had at a low rate, but no municipal plant could supply at less than a penny per unit at the present prices of coal, material, and labour. These concerns therefore aro better served by .generating their own supply, since steam is required for other purposes than power and is essential to their business.

"Engineer" scouts the idea of our following Tasmania, and refers to it as a "red herring" because the scheme is too large for him to comprehend. As long as Wellington is served electrically he is prepared to let the rest of New Zealand look after itself.

Mr. Parry in his report deplores the fact that he was forced.to discourage a large industry, from starting operations in New Zealand owing to the fact that cheap hydro-electric power was not available. I understand that this company went to Tasmania^ l Who, knows how many more have done the same? Christchureh and Dunedin have hydro.pawer. Th« latter has a stand-by plant of only 1200 h.p., and the fuel bill last year amounted to only some £200. Christchurch had been unfortunate- owing to trouble with snow, but in. spite' of' that the standby plant has not been used more than two weeks altogether during the year. An engineer who is manager of a large electric concern and who only recently returned from a trip through America, and England, informs me that .hydropower is being developed wherever possible; and in most cases stand-by plants are. found to bo almost unnecessary; there being little risk of breakdown for a properly installed plant. , Line troubles are the weak point, but these are of short duration, and mostly from climatic conditions.

If the Government -will push on our hydro schemes, and carry out Mr. Parry's intentions, there should be no question but -what cheap and ample current will be available for everyone, a.nd on the face of this it would be a great mistake for out city fathers to involve the city in a large expenditure on steam plant which would .be neither use nor o.Ttament at the end of a few years. With additions .to. Harris-street as a stand-by' plant, Mangahao -vyill be sufficient for the next 15 years, and we ; will avoid the large capital charges of a .new station. —I am, etc., | EFFICIENCY.

TO TBS EDITOR. Sir,—ln "Engineer/ the critic of the j city light and power policy, we have i obviously a prejudiced mind to deal with, j one who is not prepared to admit that the "other fellow" has a few good points in his argument; he is an artist at evading the point raised, and breaks 'off at a tangent into questions that bear no.real I weight on the points at issue. All the argument is about a stand-by plant. Is it necessary? where shall it j be situated, and above all, its capacity? Shall it be sufficient to take the fullcity load "as inferred by 'Engineer,' "or is to be designed to cope with the peak load, and finally, can the City Council afford to throw' away £500,000 in erecting an unnecessary work? I would ask those interested in this I controversy to understand that, favourably situated as we are in our freedom from snowstorms, the question of interruption on a dual transmission line from Mangahao is a very doubtful point, and I think, negligible. Our violent wind may be cited as a, favourable cause of failure, but I would point out that the whole' of the ■ wires, serving Wellington City to-day are overhead wires. You all know the complete absence of interruption, extending over years. The conclusion, therefore, ia that if we could obtain sufficient hydro-power for all purposes, no standby would be required. In support of

this assertion, why is it never »uggested to provide a stand-by to a steam plant? It is Bubjoct to more chance of failure than any hydro scheme, excepting only the long transmission lines. Unfortunately, however, the question of "peak" load demands the installation of a plant capable of supplying a large amount of current for a short time, and in the Harris-street plant, which I believe has an ultimate capacity of 9000 kilowatt, we have sufficient to meet the demand that Wellington is ever likely to impose. . The financial retnrns give us the capital charges on the Harris-street plant a-s £16.716, and owing to extensions may reach £20,000 per annum, so that the position is obviously absurd to suggest scrapping the existing siteand incurring capital charges from £40,000 to £50,000 per annum where £20,000 provides all we need. _ . • "Engineer" states I make a rash assertion in stating we cannot combine hydijo and steam power. I made no rash statement: what 1 did say was that the scheme must either be one or the other, which was brought about by "Engineer" | advocating a station able to meet the j city load in event of hydro failure, such suggestion Being a commercial impossibility. "Engineer's" comments re feeders show a lack of grip of the problem. The true facts are as follow :—Two incoming circuits would suit Mangahao, but a great multiplicity of circuits governing the switchboard system would be necessary on removing to any new site. Before closing I would point out an absolute fact that is wrongly criticised by "Engineer"—that is, the load factor and reference to the return of British Municipal Electric Light and Power Departments. It i 3 found that the average factor is under 25 per cent., and not 50 as mentioned by "Engineer." Thus the Mangahao scheme could provide an output to meet 48,000 horse-power.—l am, etc., . ELECTRIC. 12th May.'