Survey of Energy Resources 2007
Geothermal Country Notes
New Zealand is exceptionally rich in geothermal fields, as well as in a large number of other geothermal features. Temperatures range from 70°C to greater than 220°C in the 129 identified areas. Substantial capacity exists for both the generation of geothermally produced power and also for geothermal heat used directly. However, in common with many countries today, New Zealand is experiencing the effects of privatisation of its electricity industry, together with inter-fuel competition for generation, environmental concerns and the effects of climate change. These factors have all helped to slow the pace of geothermal development in recent years.
The first geothermal power plant came into operation at Wairakei, north of Lake Taupo (North Island) in November 1958. It has generated electricity for nearly 50 years and today its capacity stands at 162 MWe. Wairakei was the second geothermal power station to be built in the world and the first to tap a hot pressurised water resource. An additional 14 MWe binary capacity became operational in September 2005.
By end-2005 some 263 MWe of additional geothermal capacity had come on line, in the central North Island's Taupo Volcanic Zone (TVZ). Included in this total is the 39 MWe binary-cycle extension at the Mokai plant, which was the first geothermal development to be owned by a Maori Trust.
One further plant (10 MWe) began operating in 1998 in the locality of Northland - in the far north of North Island.
At end-2005 installed capacity for direct heat uses stood at about 350 MWt. The main user of direct heat is at Kawerau, where a 210 MWt plant generates clean process steam for various procedures within a pulp and paper mill operation. Geothermal steam at other locations is also used for agricultural drying (10% of direct-heat capacity in 2004), bathing and swimming (9%), space heating (7%) and fish and animal farming (6%).
Geothermal heat pumps are virtually unknown in New Zealand, with only isolated installations in South Island.