INTERNATIONAL SUMMER SCHOOL on Direct Application of Geothermal Energy Under the auspice of the Division of Earth Sciences DIRECT USE APPLICATIONS OF GEOTHERMAL ENERGY IN NEW ZEALAND Trevor M. Hunt1 & John W. Lund2 1 Institute of Geological & Nuclear Sciences, Private Bag 2000, Taupo, New Zealand (
[email protected]) 2 Geo-Heat Center, Oregon Institute of Technology, 3201 Campus Drive, Klamath Falls, Oregon 97601, USA. (
[email protected]) ABSTRACT temperature geothermal resources in a triangular shaped area called the Taupo Direct use of geothermal energy in Volcanic Zone (Fig. 1). In some other New Zealand is relatively small (approx. parts of the North Island low enthalpy 7000 TJ/yr) because of cheap electricity, springs occur associated with deep circu- but is increasing. At present, the greatest lation of meteoric waters; these springs use is as industrial process heat in a generally emerge at active tectonic faults. timber mill at Kawerau where fluid from a In the South Island a narrow zone of low high-temperature geothermal re-servoir is enthalpy springs occur; these are also as- used directly to heat combustion air and sociated with major tectonic faults (Fig. 1). shatter sprays in chemical recovery boi- Because of the abundance of high-en- lers, heat black liquor, and to pre-heat thalpy geothermal resources, and the boiler water. Clean steam, obtained using wide-spread availability of cheap hydro- a heat exchanger, is used to dry paper, generated electricity (US3c/kWhr, heat boiler water, and generate electricity wholesale) and natural gas, little effort has for the mill. Other significant uses are in been made to explore and develop low- space heating, timber drying, fish farming enthalpy geothermal resources except for and orchid growing.