ELECTRIC POWER

Nelson Evening Mail, Volume 76, 25 October 1941, Page 6

ELECTRIC POWER

SCOPE OF PRESENT DEVELOPMENT i MANY WORKS NOW IN HAND ! ‘The scope of the present dcvclop- | ment of electric power in New Zealand." stated Mr F. T. M. Kissel, chief engineer of the Public Works Department, in a recent address, "may best be summarised by stating that of the total area of 102.693 square miles in New ZeJland 33 per cent, of the North Island and 19 per cent, of the South Island are within the reach of the various transmission and distribution lines Ir other words, 26 per cent, of the area of New Zealand has elec--1 tricity available in it, and as the j greater part of the population lives j within that 26 per cent., 94 per cent. ;of the actual population can avail ! itself of its benefits. “Over the whole system. Governi ment and supply authority, the hydro i stations generated 96.2 per cent, of the | total units generated during the year ! ended March, 1940. The proportion jof the year ended 1941 has been I slightly less, 93.72 per cent., as the in- | crements of load had to be taken up ■ by extra running of the steam plants, ! ciue to overloaded condition of existing j hydro plants. CONSTRUCTION WORK "Under construction in the North i Island is the plant at Karapiro, on j j the Waikato river, near Cambridge. | j Work is now proceeding on plant at i this point which will, when completed, I ; have a capacity of 90.000 kw. Develop- j I ment consists of a dam on the river I which will form a lake extending back [ j as far as the tailwater level at AraI puni. It will, when completed, flood ! j out the existing hydro-electric station ! at Horahora and thus reduce the add- | ! ed capacity from 90.000 k.w by 10.000 : | kw., the capacity of this Horahora sta- j i lion. In addition, the Government { i has under construction and nearing i . completion a hydro-electric plant at j j Waikaremoana which uses the water j ! as it loaves the present power station , |by passing it through a canal and | . tunnel to a power station where 42,000 j ! kw. will be generated. In addition, j arrangements are being made for the j | installation of a further two 21.000 kw. ! I units at Arapuni. The latter two j ! plants would no-.v be veil forward but | are held up because of late deliveries J i cf plant. “In the South Island a new hydroelectric station is being built at High- ( hank on thD Rakaia station. This will i have a capacity of 25,000 kw. and will j derive its water from the irrigation ! race which is being built to bring water from the Rangitata river on to I the Canterbury Plains. “Work is also in hand for a future development at Lake Tekapo. The main purpose of this i.s to enable more use to be made of the storage available in this lake. A tunnel is being driven through the morainic dam which formed the lake, and by m?ar.-. of this tunnel and a low' dam on the present outlet of the lake it would be possible to utilise a range of about 20ft of lake level to increase the flow ,at the present Waitaki power station !in the winter time by storing in the l lake surplus water available during i the summer. This tunnel will also l mgke available a fall of about 100 ft ! which exists in the first n.ile and a | half of the river below the lake out ! let, and will enable about 25,000 kw. to | be developed in this station. SUPPLY DIFFICULTIES | “The Government has had considerable difficulty during the past 12 j months in making available power sufficient to meet the increasing de- ; mand. This has been caused by the ; delay in obtaining plant for the new | development which we have in hand. In the conditions existing the two main st'am plants in Auckland and Wellington have been able to render very great assistance by generating a considerable amount of power. Though the operation of these steam plants has served a most useful purpose in making ©ewer available, they are now having to be used to an extent which is well beyond an economic point. “In the South Island the completion cf two additional units, each of 15,000 k.w., in the Waitaki station has improved the position considerably. Dur-1 ing the past winter there was no shortage. and unless climatic conditions are exceptional w'e should have little difficulty next winter. With these two additional units the Waitaki station will be run on a high load factor during the spring and rummer months so as to reduce the demand on the Lake Coleridge and Waipori stations, and ensure that the storage available at these two stations is filled and available for power generation in the winter peak load period when the flow in the Waitaki River is at minimum i and much below what is required for the machines there.”