Geothermal energy has the potential to make a significant contribution to New Zealand’s energy requirements, either through electricity generation or, with even higher levels of efficiency, as a direct source of heat. However, because geothermal steam cannot be transported for more than a few tens of kilometres, the opportunities for direct use are limited and large-scale electricity generation is the most attractive option.
New Zealand has substantial geothermal resources that are accessible and untapped. The most comprehensive recent assessment of New Zealand’s high temperature geothermal resources is that by Lawless (2002), the total resource is estimated as equivalent to a median value of 3600 MWe of electrical generation, using only existing technology. A total of 584 MWe is currently installed. Existing development thus represents only about 15 % of the total high temperature resource.
Assessment of New Zealands High Temperature Geothermal Resources
Based on a stored heat calculation: Source: Lawless 2002
- Excludes Lake Rotorua
- Excludes Lake Rotoiti
- Includes Waikite
- Mean temperature through acessible reservoir thickness and area, not maximum, and for developed fields, before exploitation
- Three values are 10, 50 and 90th percentile
|Means and Totals:||9.5||250||2500||3600||5000|
There are various limitations on field development. In some cases, Regional Councils place a high degree of protection on certain resources. As the calculations of field capacity assume a limited amount of stored heat, allowance has to be made by past extractive use of the resource. On this basis, the following table indicates over 1200 MW of additional capacity could eventually be developed over and above current developments, though not all of this will be economic. Over half of this potential capacity buildup would be brownfield stepouts from existing developments on proven fields.
Assessment of Restricted Geothermal Potential (Updated 2014)
|Capacity Minus Environmental Limitations (MW)||Existing Generation or Use (MW)||Equivalent Period of Past Use (years)||Calculated Available Additional Capacity
(based on modelling
(based on modelling
A potentially important component of future development options has been the continued Government ownership of 102 unused geothermal wells in the Central North Island. These assets and their associated IP have been administered by Treasury. Government has signalled its intention to develop these assets by naming Mighty River Power as its developer. In an initial step Kawerau geothermal assets were transferred to Mighty River Power in July 2005, with a back-to-back deal for transfer to
Deep geothermal drilling and extraction technology has the potential to exploit additional sources of geothermal energy derived from the near-magmatic conditions in deep geothermal systems or systems without surface features. Developments based on these unexplored resources could result in new developments without undesirable effects such as subsidence.
Increased geothermal electricity generation in New Zealand can assist the short-term supply situation and also contribute significantly to long term generation growth. The barriers to ongoing development of geothermal energy in New Zealand are not technical, nor absolute cost, but regulatory and its cost relative to alternatives.
- Lawless, J V 2002: New Zealand’s geothermal resource revisited. New Zealand Geothermal Association Annual Seminar, Taupo.
- Lawless, J V 2004: New Zealand’s geothermal opportunities. New Zealand Geothermal Association Annual Seminar, Taupo.
The Renewable Energy Industry Status Report – Wind, Hydro & Geothermal
EECA (2MB PDF)
Power Generation Options for New Zealand
Sinclair Knight Merz Limited
2000-2005 New Zealand Country Update
Proceedings World Geothermal Congress 2005
1995-2000 Update report on the existing and planned use of geothermal energy for electricity generation and direct use in New Zealand
Ian Thain, Michael Dunstall
Proceedings World Geothermal Congress 2000