Hotter and Deeper: New Zealand’s Research Programme to Harness Its Deep Geothermal Resources

Abstract

New Zealand’s conventional geothermal resources generate ~600 MWe (~10% total electricity generation), and are currently utilised to a depth of less than 3 km, where temperatures are up to 330oC. Utilisation of known geothermal resources could increase generation to 2,000 MWe, based on a conservative estimate of currently drillable and likely consentable systems in the Taupo Volcanic Zone (TVZ). Deep geothermal resources at depths of up to 5-7 km (where temperatures exceed 400oC), could exceed a potential of 10,000 MWe. This is close to the total New Zealand 2008 installed generating capacity.
A research programme has been established to better quantify New Zealand’s deep geothermal resource potential. The research is lead by GNS Science, and includes specialist expertise from University of Auckland, Victoria University of Wellington, Industrial Research Ltd, and involves a network of international collaborations. The deep geothermal research, is funded by the New Zealand Government and supplemented with industry support, and is for 4 years. Two research themes are covered: (a) improved understanding of the deep structure and dynamics of the Taupo-Reporoa Basin. This is New Zealand’s most intense area of deep-seated geothermal manifestations, and (b) greater understanding of the physical and chemical nature of the deep fluids and flow production pathways.