POWER SUPPLY

Waikato Times, Volume 127, Issue 21220, 17 September 1940, Page 6

POWER SUPPLY

AVOIDING SHORTAGE NORTH ISLAND ACTIVITY SCHEMES IN WAIKATO BASIN COAL STORAGE AT AUCKLAND Although considerable development of hydro-electric power generation is being undertaken in the North Island, particularly in the Waikato basin, it is likely to be some time before the constructional work has been advanced to a stage where the electric power supply to meet the everincreasing demand in the North Island is assured. It is during the winter months that the demand taxes the available supply. This winter some difficulty was encountered in maintaining the output to a degree sufficient to meet the peak loads. In an effort to avoid similar problems in the immediate future, if possible, and to eliminate them entirely by the following year, the Public Works Department is planning to meet the demand. The available output of hydro-electricity depends largely upon the weather and the resultant volume of water available in the river, but it Is not unlikely that the coining autumn will present a somewhat bigger problem than last year. Taupo Control Scheme In order to remedy the seasonal shortage of water in the Waikato River, a plan was conceived sojne time ago for the construction of a “lip” on Lake Taupo. The scheme was to erect control gates at the outlet of the lake, so that when the thaw from the mountain snow was greatest the excess volume of water could be stored in the lake and released through the control gates gradually during the summer, in order to maintain the level of the Waikato River at a more or less constant mark throughout the year. In this way the summer shortage of volume for generation at Arapuni would be overcome. The project was put in hand and excellent progress is being made by the Public Works Department. The excavation for the dam is completed and the time has arrived for the pouring of the concrete for the construction of the bridge and control dam, which will include six gates. Enlarging Arapuni Although progress on the Lake Taupo control scheme is excellent, the project will not be in operation in time to conserve any of the thaw flood this spring. It should be completed during next winter, however, and will be working, it is hoped, in time to safeguard the summer level of the Waikato River during the 1941-42 summer. Further improvement of the .power position will come when the s'cheme for the installation of two additional turbines at Arapuni is complete. This involves the importation of machinery from Great Britain, and difficulties and delays are quite probable during a time of war. If shipping and other plans go according to present expectations the installation of the two new units may be complete by about this time next year. The plant for the work was due at Arapuni in August and it was expected that the installation would be complete next June, but it is understood the turbines have not yet been despatched from the United Kingdom. New Power Project Two new turbines at Arapuni will give the power station extra capacity for handling a peak load. The production of sufficient units to meet requirements will still depend, however, on the volume of water available in the river. Until this is assured it will still be necessary to bum coal at the King’s Wharf generating station in Auckland in order to provide the required number of units. Construction has commenced on the erection of a large hydro-elec-tric power station at the Crow's Nest, near Cambridge, though no relief to the power position in the North Island can be expected from this scheme for three or four years. The first assistance to Arapuni will come from the Lake Waikaremoana project, which is of considerable size. Next winter this station should be able to take over a share of the North Island load. Little benefit, therefore, can be expected this summer from any of these hydro-electric generating schemes. Plans for the immediate safeguarding of the supply of electric power during next winter must bt cbneentrated on the auxiliary sla!j“ Kin g's Wharf, Auckland. With this in view steps have been taken to build up the reserve stocks of coal for use at this station. 2000 Tons Coal Reserve There is little guarantee that sufficient coal will be available from the Waikato mines for the Auckland plant, and it was recommended to the Auckland Electrical Power Board by the District Electrical Engineer, Hamilton, that an additional 2000 tons of Liverpool and James coal should be imported and stored. The board agreed to accept this plan The storing of Waikato coal is difficult as it over-heats, and sufficient day to day output of coal during the summer for the King's Wharf plant is not assured. For some time suitable coal for storing has been sought, keeping in mind that the King’s Wharf furnaces were constructed specially to suit Waikato coal. 1000 Tons a Week The engineer’s letter to the Auck-. land board stated that the requirements of King's Wharf were estimated at 1000 tons a week until February next. This estimate was based on the steadily falling level at Taupo and the diminution of oil fuel consumption at Evans Bay, Wellington. He said he was endeavouring to arrange for an exchange of 400 tons of Waikato coal in place of a similar amount of other coal with the dairy factories. If this were done it would enable the present 800 tons allotment of Waikato coal to be reduced to 600 tons which, with the additional 400 tons made available, would provide the desired 1000 tons a week. It is understood that no arrangements with the dairy companies have yet been made.