SOURCES OF GEOTHERMAL STEAM FOR POWER

Taupo Times, Volume V, Issue 208, 27 January 1956, Page 1

SOURCES OF GEOTHERMAL STEAM FOR POWER

Research at Orakei-Korako For several years the centre of interest in connection with the poss.i-b.il-ity of generating electric power by the use of geothermal steam has been at Wairakei. With the project there now reaching the stage when actual construetion of a power plant is imminent, attention naturally tnrns to other areas where geothermal steam may be exploitable. Some time ago Waiotapu and Orakei-korako were listed as being likely sources of power steam. Tests are already being made at Waiotapu. This area was probably selected for first attention because of the ease of access but now more and more attention is being focussed on Orakeikorako. There is a possibility that dotailed scientific investigations will show that there is an area near the scenic spots at Orakei-korako which will have a power potential equally as big as the area now being exploited at Wairakei. It is also becoming evident that this mighty source of power is concentrated in an area only a quarter of the size of the Wairakei area. Because so little fundamental knowledge of underground heat has been obtained scientists have little to judge a potential power-producing area by. For lack of some better yardstick they judge potentialities by the natural heat output of any selected area. in the form of geysers, hot springs and steaming ground. They realise that the power potential may not be directly related to the natural heat output but accept it, in the absence of a better guiae, as a rough measure. Two young scientists of the Department of Scientific and Industrial Research recently spent some time in the Orakei-korako district sampling the natural heat output of the area. Various devices have been developed to measure ihe natural heat output of such phenomena as geysers and hot pools and samples taken over a wide area can be used to make a rough assessment of the total heat output. This is then put into the hands of a second scientific team who, with the aid of a probe, take underground temperatures. These are plotted on a map and the map then indicates which are the most likely spots to put down experimental

bores. Messrs R. F. Benseman and J. Mautner, the Dominion Physieal Baboratory team who made the initial investigations, marked out an area around Orakei-korako of 84 acres which showed signs of thermal activity and which could be the future site of steam-producing geothermal bores. Huge Heat Output

Some idea of the natural heat output of the area can be gauged from the fact that one hot spring, the Hochstetter, is now producing enough boiling water each day to supply a city the size of Wellington with its daily domestic hot water needs. A round milllon gallons of boiling water flows to waste into the Waikato River from the Hochstetter Spring every 24 hours. About two years ago this spring was not very active but it then suddenly experienced a surge of activity and in a very short space of time turned itself into a geyser. In due course the geyser disfippeared but left behind it a very hot pool with a rer markable output of boiling water. (Continued on poge 4)