Use of the Shallow Hydrothermal Resource at Tauhara Geothermal Field, Taupo

Abstract

A survey in 1986/87 established that in excess of 500 bores exist in Taupo, providing energy for commercial and domestic heating. Approximately 90% of those bores are currently used; nearly half of which utilise downhole heat exchangers. It has been estimated that the total energy consumption from thermal ground water is around 2.76 x 108MJ.y~1 , 4.5% of the natural heat flow of around 200MW. Eighty-five percent of that consumption comes from a few large commercial users. The heat resource is therefore not stressed by current use and it is perceived that the primary management problem in the near future will be interference between users. Pumping tests are being undertaken to determine aquifer characteristics and initial indications are that interference is unlikely in the southern, Waipahihi area of Taupo, where transmissivities are high (=700m .d ). However, at the northern end of Taupo the aquifer appears to be less permeable and problems may occur in this area with resource use. Some drawdown effects have already occurred in this area.