THE POWER POSITION

Bay of Plenty Beacon, Volume 11, Issue 49, 4 July 1947, Page 5

THE POWER POSITION

FACES DIM FUTURE

GRAVE DEFICIENCIES PREDICTED Following’ the near-cessation of power cuts the public are wondering what the future has in store for them. Grave deficiencies in future years of New Zealand’s hydro-electric power development schemes are foreseen by Mr N. G. McLeod, chief engineer to the Thames Valley Electric Power Board in a report he presented at a recent conference of Auckland Provincial electricity engineers at Rotorua. Mr McLeod has based his report on certain assumptions, which are limited to the completion of the Lake Waikaremoana scheme and the ten proposed stations on the Waikato River. As one of the very hard hit districts Whakatane will be vitally affected should the events predicted come to pass. For this reason a detailed report is given "below. The assumptions are as follows: A. 10 Year Scheme.— This assumes that Kaitawa and full Karapiro will be in operation for 1948, that Maraetai will be in operation in 1950, and that the seven remaining proposed stations on the Waikato come into operation at one year intervals after that.

B. 11 Years Scheme. —This assumes that Maraetai will not come into operation till 1951, but the remaining stations at one year intervals after that. C. 17 Year Scheme. —This assumes that Maraetai comes into operation in 1950, and the remaining Waikato stations at two years intervals after that.

For each of the above schemes, average annual increase of 8 per cent., 10 per cent., 12 per cent., and 15 per cent, have been taken, the increases being on the assumption that the existing North Island stations of all kinds, including the first 30,000 k.w. stations at Karapiro, are sufficient at all .times to handle a peak load of 340,000 k.w. at normal 'load factor. This 340,000 k.w. has been taken as the base or starting .load, and it applies to 1947. Consideration has been given to 'two possible conditions:— (a) That hydraulic conditions are such that the full rated capacity of the hydro-stations proposed to be added is available throughout the years following their completion. (b) That only half the rated capacity of the added stations is available severe dry periods. Rate of Increase

'What this will be depends upon many factors, some of which may interlink with one another. Some of the principal ones are:— Availability of suitable generating -plants; availability of users’ equipment; availability of necessary labour; economic conditions, whether boom, normal or slump;weather conditions, affecting initially primary production and finally all classes ; availability of materials, fittings, plant and labour, for the building and equipping of homes, factories and offices; military operations; and population.

The effect of a depression can be seen from the board’s own experience. In 1934 our connected load increased by only 7.8 per cent, over the previous year. Improving economic conditions resulted in an increase of 18.1 per cent, in 1939, and for the three years to 1939 averaged 16.3 per cent, increase.

The effect of the war was a drop from 18.1 per cent, in 1939, to 1.4 per cent, in 1944, the average for the three years 1943-45 being only 2.67 per cent. This drop was due to shortage of power, shortage of materials and shortage of labour. These shortages still persist. It is understood that ilie department is basing its generating capacity on an average increase of 10 per cent, per annum. This may be fairly safe basis in normal circumstances, when all demands could be met as they arose, but following such a long period of restriction as has existed since the beginning of 1940, it is likely to be found too low for several years following the removal of restrictions. It could be held to 10 per cent, or lower by a continuation of restrictions. It is for these reasons that average increases from 8 to 15 per cent, have been calculated and plotted, in order that the effect of such variations may be more readily appreciated.

In the statement of the loads to be expected under the varying conditions, no provision is made for'reserve plant, to deal with breakdowns in individual units, or in the

isolation of stations. This would be a requirement additional to those scheduled. Net Capacities Required Scheme A. —With full generating capacity available there would be ample plant to handle the 8 to 10 per cent, increases for the period of 10 years; the 12 per cent, increase for a period of nine years; and the 15 per cent, increase for a period of seven years, though the second year would show a small deficiency. With dry weather conditions somewhat similar to those recently experienced, when there was sufficient water in the Waikato River to run only the one unit at Karapiro, the position would not be so good. Next year there would be sufficient to handle about a 13 per cent, increase in load. The second year there would be a deficiency throughout, that at an average increase of 8 per cent, in load being deficient by approximately 11,000 k.w., at 10 per cent, about 25,000 k.w.; at 12 per cent, about 41,000 k.w.; and at 15 per cent, about 54,000 k.w. In the third year, when it is assumed Maraetai would come into operation and the position is improved, up to 12 per cent, average increase could be carried, but no more. The 8 per cent, increase could be carried for eight years and the 10 per cent, for five years. The other percentages show increasing deficiencies.

In the seventh year the deficiencies indicated are for an average increase of 10 per cent., 37,000 k.w.; 12 per cent., 126,000 k.w.; 15 per cent., 278,000 k.w.

In the 10th year the position is very much worse. The deficiency for an average increase of 8 per cent, would be about 48,000 k.w.; 10 per cent., 196,000 k.w.; 12 per cent., 369,000 k.w.; 15 per cent., 690,000 k.w. Scheme B. —ll year term, with Mgraetai not coming in until the fourth year: With full generation, the 8 per cent, average increase could be handled throughout, alos the 10 per cent, except for the third year. The 12 per cent, increase could be handled for the first and second and for the fourth to the eighth years. The 15 per cent, could be handled for the first, fourth and fifth years only. With dry weather conditions the 8 per cent, could be carried in the first, fourth and fifth years, and very nearly carried on in the sixth and seventh years.. The 10 per cent, and 12 per cent, could be carried in the first year, but not thereafter. The deficiencies in the fifth year would be as follows: At 10 per cent, average rate, 2,000 k.w.; 12 per cent., 73,000 k.w.; 15 per cent. 158,000 k.w. In the 11th year the following would be the deficiencies for the different average rates of increase in load: 8 per cent., 106,000 k.w.; 10 per cent., 284,000 k.w.; 12 per cent, 496,000 k.w.; 15 per cent, 896,000 k.w.

Scheme C.—l 7 year term, with Maraetai coming in in the third year, and the seven succeeding Waikato stations at two-year intervals, and with full generating caapcity available, the 8 per cent, increase could be handled for 13 years, the 10 per cent, for nine years, the 12 per cent, for seven years, and the 15 per cent, for the first, third, fourth and fifth years only. At the end of 10 years the' deficiencies would be: At 10 per cent., rate, 70,000 k.w.; 12 per cent., 243,000 k.w.; 15 per cent., 564,000 k.w. At the end of 17 years the deficiencies would be: At 8 per cent, rate, 25,000 k.w.; 10 per cent., 687,000 k.w.; 12 per cent., 1,300,000 k.w.; 15 per cent., 2,627,000 k.w. These figures may appear astronomical, but the dry weather position is still worse. Dry Weather Conditions All loads could be carried in the first year, but none of the scheduled percentages in the second. The 8 per cent, increase could be carried in the third and fourth and fifth years, but not thereafter. The 10 per cent, and 12 per cent, could be carried for the third year, but not after that. The 15 per cent, increase could not be handled after the first year.

The deficiencies in kilowatts in the eighth and 16th years respectively would be as follows:

Standby, or Load-Building Plants It does appear that a rate of increase of not less than 12 per cent, should be for a period of 5 years following completion of Maraetai Station, and based on dryweather condiitons.

The provision of standby-plant, should be such as to fill up deficiencies pending completion of the hydro-schemes. These non-hydro plants may be standby or load-build-ing plants. Eventually they would become fulltime plants. Looking still further into the future, since the available hydraulic power has its limit, these non-hydro plants will possibly overshadow, more and more, the capacity available from the waterpowers in New Zealand.

Accepting the 12 per cent, rate of increase, and the possibility of a dry spell, the question of when standbys should be installed, and their capacities depend upon the rate at which the proposed new stations on the Waikato are completed.

will not be ready till 1951, that Whakamaru will not be ready till 1953, and that Waipapa, Atiamuri and Ohakuri come into service in 1954, 1955 and 1956 respectively, the standby plant required (apart from that necessary to handle breakdowns in plant, or plant isolations) can readily be determined.

It is unfortunate that there is not sufficient plant installed to handle the pent-up load from now on, but information should be available as to the expected times of completion of the various generating plants, and the proposals to meet the expected possible demands under dry weather conditions.

If these things were known, the position could be more accurately forecast. It should not be assumed that a generating plant standing idle is an economic waste, any more than it should be assumed that insurance on a house is an economic waste if the house is not destroyed. The load built up because of the known available capacity to handle it, and the greater production and employment it ensures,- are of far greater economic value to the Dominion than the fixed charges on a plant standing by to deal with special emergencies.

Rate of Increase 8 Years 16 Years Per cent. k.w. k.w. 8 78,000 571,000 10 178,000 1,033,000 12 291,000 1,647,000 15 489,000 2,973,000