Geothermal developments in New-Zealand

Significant developments started in the late 1950’s with large scale fluid production to generate electricity (at Wairakei in 1958) and to obtain process heat (at Kawerau, also in 1958). All thermal fluids were produced from liquid dominated, high-T systems. There are c. 20 such systems concentrated in the c. 200 km long Taupo Volcanic zone segment and one in Northland. Six of these systems (including the one in Northland) are presently exploited for electricity generation with an installed total capacity of c. 560 MWe (end of 2008) contributing about 10 % (4070 GWhr/yr) to the national electricity production. Another nine systems are protected or semi-protected because of their unique setting and manifestations.

Direct use of geothermal fluids for timber processing also started in 1958 (with an initial abstraction of c. 200 MWth). Direct utilization increased slowly with most fluids coming from a few, high-T reservoirs. Energy production has reached c. 13,500 TJ/yr (at the end of 2008). Most of it (69%) is still being used for timber processing and 20 % for bathing. Utilization of other geothermal resources (low-T systems, for example) is very small (c. 350 TJ/yr for bathing). The main challenges of future developments will be improvement of extraction and utilization efficiency by all users abstracting fluids from high-T systems and to continue with the expansion of electricity production (target of c. 750 MWe plant capacity by the end of 2010).