DAYLIGHT SAVING

Evening Post, Volume CXXXI, Issue 13, 16 January 1941, Page 11

DAYLIGHT SAVING

NATIONAL ECONOMY

TO CUT POWER DEMAND

A SERIOUS PROBLEM

Some days ago the feasibility of an extension of daylight saving as the most ready means of effecting a necessary national economy in the consumption of electric power was suggested in an article in "The Post*" The suggestion was not supported by figures of possible economy and an endeavour has since been made to obtain such statistical support. It is not a simple matter, for a detailed calculation of possible saving of electrical power requires a. particular and expert knowledge of a mass of statistics of loading which changes from month to month. But* what is evident from the further consideration is that an extension of daylight saving will effect a really useful reduction, When daylight saving was introduced into New Zealand in: 1927, it was debated as a matter of politics and of misunderstanding, often as of understanding. From its original full hour— the saving practically everywhere else in the world—New Zealand daylight saving came down to 30 minutes after one year, and the politics of it went out with understanding. Now the position is such that an extension of, daylight saving has become a question o| serious national economy. The position is that the demand for power is outpacing generating capacity, and that there are two alternatives ahead: the painless reduction of demand during as great a period of the year as possible by an extension of daylight - saving, or a rationing of power and the cutting off of electrical equipment which can, under necessity, be done without, but only at great, inconvenience. . There is a third possibility—that the demand may be met by bringing into commission every available steam standby station, at a consequent extremely heavy cost for imported fuel. The power position is more difficult in the North than in the South Island, though there are certain districts in the south where local difficulties have already dictated curtailment of the use of power. It is in the North Island that the load has grown most rapidly, till the three big Public Works stations. Arapuni, Waikaremoana. and Mangahao, cannot, even in the summer, meet that demand, hence the continued running of the Evans Bay steam station, burning coal and oil at a cost of thousands of pounds a month. Plans long ago laid by the hydroelectric branch of the Public Works Department would have met the position this year under peace conditions, but the war has disrupted delivery of plant needed this year. That plant, to give about 90.000 kilowatts additional for the North Island alone, will eventually arrive, but not in time to meet the great demand next winter. SAVING FROM DAYLIGHT SAVING. Daylight saving could not bring about economy in power used in industry, trams, and electric trains, or for cooking, heating, and water heating, but it would reduce power used for private, commercial, and street lighting, for power used in night advertising, and possibly indirectly as well. A writer in the Christchurch "Press," Mr. Arthur Lush, 8.E., A.M.1.C.E., has stated possible saving in a simple way. He pointed out that at present the daylight saving period is from the last Sunday in September (September 28) to the last Sunday in April (April 27), and thus is 30 minutes for 211 days, or 105 hours a year. Assuming that household lights are burned 1000 hours a year, an extension to the full hour would mean a saving of 10 per cent, in the year's bill for current and, of course, in lamps, all imported, whether complete or in parts for assembly. LONGER SUMMER TIME? . Mr. Lush did not discuss the percentage saving that would result if the daylight saving period began earlier than September 28 and continued after April 27 while there is still a workable margin of morning and evening daylight. Plainly the percentage saving will be considerably greater if this can be done, and by sun rising and setting times it can be done. On April 27 the sun rises at 6.32 a.m. and sets at 5.05 p.m., New Zealand mean time. On September 23 the sun rises at 5.32 a.m. and sets at 5.33 p.m If daylight saving began a full month earlier in future years the sun rising and setting times would be as good as in April, when daylight saving now ends, for on August 24 (fourth Sunday in August) the rising and setting times are 6.30 a.m. and 5.18 p.m.— better, in fact, than at April 27. Such an earlier start, however, will not help this year; the lengthening of the halfhour to the full hour would effect an economy of at least 10 per cent, in both remaining months of summer time this year. SUMMER TIME OVERSEAS. That daylight saving is sound economy in peace or war is proved surely by the wide acceptance of its benefits. Britain adopted daylight saving during the war of 1914-18 as a measure of national economy, and the full hour remained in force from April 16 to October 7 each year. Britain has extended the saving period right through the year in this war to save the last possible minutes of the day so that overlap of working time into the black-out hours may be the minimum—essentially again a matter of national economy I and convenience. France, Belgium, the Netherlands, Germany have the hour. Italy proposed an hour and a half, but there is no record of the adoption of that daily saving. The North and South Americas have the hour in whole national areas or in states only. New Zealand alone, apparently, has 30 minutes. Gold Coast, Africa, has 201 minutes for four months only, an apparently trifling saving, but the most that could be made of the small variations of sun rising and setting times near the Equator. New Zealand, on the other hand, makes minimum use of daylight hours. [ LIGHTING LOAD HERE. Wellington City cannot be a guide for the rest of New Zealand, for loading characteristics vary much from locality to locality, but the city figures are some foundation for a general case. Last year Wellington consumed 3,000,000 units in private lighting, 17,000,000 in commercial lighting, and 2,000,000 in street lighting, about 20 per cent, of the total units supplied. A saving of one-tenth of that demand means, say, 2 per cent, of the total. It does not mean much, but when the figures run over the one hundred million two per cent.becomes a very large figure indeed. In other towns where the power and tram demand is low or" practically non-existent the lighting proportion is far greater and the possible saving greater. It is because demand has outpaced hydro-electric supply that the Evans Bay steam station- is kept running at the requirement of the Public Works

Department. The output from Evans Bay varies a great deal from month to month, but in even the lightest months the fuel bill runs into thousands and in months of heavy running into tens of thousands, for oil brought from overseas and coal in short supply. That the Evans Bay station is operated almost continuously under such circumstances is full proof that the power problem is serious. An extension of daylight saving, whether by increasing the 30 minutes to 60 minutes, or by lengthening the Summer Time period, or by both, would effect a substantial economy to the consumer, to the supplying authority, and in imported oil and New Zealand coal. The alternative, if the problem grows, may be rationing—curtailment of the use of power for water heating, street, highway, decorative, and advertising lighting, and severe discouragement at least of the use of power for heating.