[ Last Updated 17 January 2006 ]
Short Description
This note provides information on New Zealand's existing and potential geothermal resource for electricity generation. This information is intended to supplement the Ministry's project to identify waterbodies of national importance in relation...
Author
Matthew Hall, Policy Analyst, Resources and Networks Branch
1 April 2004
Contents
1. This note provides information on New Zealand's existing and potential geothermal resource for electricity generation. This information is intended to supplement the Ministry's project to identify waterbodies of national importance in relation to existing and potential hydro generation.
Existing Geothermal Electricity Generation
2. The majority of New Zealand's geothermal generating capacity is situated in the Taupo Volcanic Zone in the upper North Island. In this region over 400MW of plant has been installed. Another 9MW has been installed at the top of the North Island with plans to expand this plant further. Geothermal generation accounts for approximately 7% of New Zealand's total electricity generation.
3. Figure 1 shows the location of high temperature geothermal fields in the North Island of New Zealand. Table 1 shows a summary of existing electricity generation by geothermal field.
Figure 1: High Temperature Geothermal Fields in New Zealand
Source: CAE: New Zealand's Energy Future, August 2003.
Table 1: Existing Electricity Generation by Geothermal Field| Rank | Geothermal field name | Total installed capacity (MW) | Annual electricity production1 (GWh) | Number of power plants | % of GWhp.a. | Nationally important at a threshold of 230GWh? |
| 1 | Wairākei | 220 | 1,734 | 2 | 51.0% | Yes |
| 2 | Ohaaki | 104 | 820 | 1 | 24.1% | Yes |
| 3 | Mōkai | 55 | 434 | 1 | 12.8% | Yes |
| 4 | Rotokawa | 28 | 221 | 1 | 6.5% | No |
| 5 | Kawerau | 15 | 118 | 2 | 3.5% | No |
| 6 | Ngāwhā | 9 | 71 | 1 | 2.1% | No |
| TOTAL | | 431 | 3,398 | 8 | 100% | |
4. At a threshold of 230GWh per annum, the Wairākei, Ohaaki and Mōkai geothermal fields are considered nationally important in terms of existing electricity generation.
Potential Geothermal Energy Generation
5. Geothermal energy could make a significant additional contribution to New Zealand's generating capacity. Delays and uncertainties in the resource consent process and subsequent compliance costs have been identified as the biggest obstacles to investment.
6. Table 2 shows a summary of potential electricity generation by geothermal field. The table is based on opportunities deemed to have a high to medium probability of progressing by 2025. It is derived from information collected by East Harbour Management Services in their 2002 report Availabilities and Costs of Renewable Sources of Energy for Generating Electricity and Heat.
Table 2: Potential Electricity Generation (with a High to Medium Probability of Proceeding by 2025) by Geothermal Field| Rank | Geothermal field name | Potential additional capacity (MW) | Potential electricity production (GWhp.a.) | % of GWhp.a. | Nationally important at a threshold of 230GWh? |
| 1 | Kawerau | 357 | 2,810 | 26.8% | Yes |
| 2 | Rotokawa | 303 | 2,390 | 22.8% | Yes |
| 3 | Wairākei | 182 | 1,430 | 13.6% | Yes |
| 4 | Ngātamariki2 | 140 | 1,104 | 10.5% | Yes |
| 5 | Mōkai | 97 | 770 | 7.3% | Yes |
| 6 | Tauhara | 70 | 550 | 5.2% | Yes |
| 7 | Mangakino3 | 65 | 512 | 4.9% | Yes |
| 8 | Ngāwhā | 64 | 500 | 4.8% | Yes |
| 9 | Rotomā | 35 | 280 | 2.7% | Yes |
| 10 | Tikitere-Tāheke | 10 | 80 | 0.7% | No |
| 11 | Horohoro | 9 | 70 | 0.7% | No |
| TOTAL | | 1,332 | 10,496 | 100% | |
7. At a threshold of 230GWh per annum, the Kawerau, Rotokawa, Wairākei, Ngātamariki, Mōkai, Tauhara, Mangakino, Ngāwhā and Rotomā geothermal fields are considered nationally important in terms of potential electricity generation. Note that the Wairākei field is considered nationally important in terms of both existing and potential electricity generation.