Wikipedia

Geothermal power in New Zealand

Geothermal power in New Zealand plays a significant part of the energy generation capacity of the country, constituting 25% of the total energy supply and 19% of electricity production in 2021. This positions New Zealand as the top user of geothermal energy among International Energy Agency (IEA) countries in both total energy supply and electricity generation.[1][2]

New geothermal drilling north of Taupō (2007)

Geothermal energy constitutes New Zealand's second-largest renewable electricity source, with the North Island estimated to have a potential of 1,000 MW for power generation. However, full exploitation may be constrained by economic, environmental, and social considerations. Exploration in the South Island has revealed geothermal prospects beneath the Alpine Fault, yet the Institute of Geological and Nuclear Science (GNS) suggests these resources are likely minor, suited more for small-scale direct use than for extensive electricity generation.[1][2]

Geothermal energy has been described as New Zealand's most reliable renewable energy source, above wind, solar and even hydroelectricity, due to its lack of dependence on the weather.[3] It has also been described as the currently (2000s and 2010s) most attractive new source of energy for New Zealand, as petrochemical fuel prices rise and easy hydro power sites have been tapped - it has been estimated that another 1000MW of geothermal resource can be used for generating electricity.[4]

Electricity generation

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In 2021, New Zealand generated a total of 45 TWh of electricity, with renewable energy sources contributing 81%, or 36 TWh. Among these, geothermal energy stood out by providing 19%. Over the period from 2005 to 2021, there has been a consistent increase in the share of renewable energy in electricity production. Specifically, the use of geothermal sources for generating electricity saw a substantial rise, growing by 165% during this period.[1][2]

Geothermal fields

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The exploration of New Zealand's geothermal fields has been very extensive, and by the 1980s, most fields were considered mapped, with 129 found, of which 14 are in the 70-140 °C range, 7 in the 140-220 °C range and 15 in the >220 °C range. Currently, some potential new geothermal fields are being surveyed that have no surface expression.[5]

New Zealand's high-temperature geothermal fields are mostly concentrated around the Taupō Volcanic Zone (which also has most of the currently operating generation capacity),[6] in the central North Island, with another major field at Ngawha Springs in Northland. However, more systems (some of them potentially exploitable) are scattered all over the country, from the Hauraki Plains to the Bay of Plenty to numerous hot springs in the South Island, most of them associated with faults and other tectonic features.[5]

Many applications of geothermal energy in New Zealand reinject the cooled steam / fluid back into the underground fields, to extend or infinitely use the fields as power sources.[3]

History

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The Wairakei geothermal power plant

Geothermal energy use in New Zealand is strongly tied to Wairakei, where the first geothermal plant was opened in 1958. At that time, it was only the second large-scale plant existing worldwide (the first being the Valle del Diavolo 'Devil's Valley' plant in Larderello, Italy opened in 1911).[7] Several new plants and efficiency-enhancing second-stage equipment have been added since, though there is also some loss of steam generation due to the decade-long drawdown. Some plants are therefore capped in steam extraction volumes to allow the fields to regenerate, and a percentage of the steam/water is reinjected.[6][5]

The Mokai and Rotokawa geothermal plant was the first to come into operation via a resource consent applied for and issued under the Resource Management Act. The 5 years up until 2016 saw a number of new power stations completed. Kawarau 90MW, Nga Awa Purua 140MW, Ngatamariki 80MW and Te Mihi 140MW.[citation needed]

For over six decades, geothermal energy has been a key component of New Zealand's electricity landscape, with the majority of its facilities situated in the Taupō Volcanic Zone. Looking ahead, it is projected that by 2030, the electricity generated from geothermal sources in New Zealand will reach approximately 10.3 terawatt-hours (TWh).[1][2]

Research

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Considerable geothermal research expertise exists at New Zealand's Crown Research Institutes and universities. In particular, at GNS Science,[8] Industrial Research Limited,[9] and the Geothermal Program at the University of Auckland. New Zealand is also one of the partner nations of the International Partnership for Energy development in Island Nations (EDIN). As part of EDIN,[10] New Zealand is involved in international research projects to evaluate and increase geothermal power generation domestically as well as in 18 Pacific Island nations.[11]

Laws and regulations

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Geothermal Energy Act 1953

The Geothermal Energy Act 1953 was made redundant by the Resource Management Act 1991 (RMA). The Geothermal Energy Act granted water rights, which have generally been replaced by RMA resource consents.[12]

Geothermal Energy Regulations 1961

The Geothermal Energy Regulations 1961 define the role of "geothermal inspectors" and specify processes for applications for authorities and licences.[13]

Rotorua City Geothermal Energy Empowering Act 1967

The Rotorua City Geothermal Energy Empowering Act 1967 is an Act to enable the Rotorua City Council to make provisions for the control of the tapping and use of geothermal energy in the city of Rotorua.

Resource Management Act 1991

The Resource Management Act 1991 (RMA) is a significant, and at times, controversial Act of Parliament passed in 1991. The RMA regulates access to natural and physical resources such as land, air and water, with sustainable use of these resources being the overriding goal. New Zealand's Ministry for the Environment describes the RMA as New Zealand's principal legislation for environmental management.[14]

The Resource Management Act is the principal legislation controlling the use of geothermal resources in New Zealand. The New Zealand Geothermal Association considers the procedures which are currently being adopted under the RMA as the single largest obstacle to further geothermal development, holding that "the regulatory process leads to long delays which impose a significant up-front cost on projects, reducing their financial viability".[12]

List of geothermal power stations

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See also: List of power stations in New Zealand
Name Location Field Operator Capacity (MW) Annual Generation
(average GWh)		 Commissioned
Kawerau (TAOM) - Te Ahi O Maui West of Kawerau, Bay of Plenty Kawerau Eastland Generation 28 208 2018
Kawerau (GDL) - Geothermal Development Limited Kawerau, Bay of Plenty Kawerau Eastland Generation 8.3 70 2008
Kawerau (TOPP1) Kawerau, Bay of Plenty Kawerau Norske Skog Tasman 25 210 2012
Kawerau (KGL) Kawerau, Bay of Plenty Kawerau Mercury 100 800 2008
Mokai northwest of Taupō Mokai Mercury 112 900 2000
Nga Awa Purua north of Taupō Rotokawa Mercury 140 1100 2010
Ngatamariki north of Taupō Ngatamariki Mercury 82 670 2013
Ngāwhā near Kaikohe, Northland Ngawha Top Energy 57 78 1998, 2020
Ohaaki between Rotorua and Taupō Ohaaki Contact Energy 70 300 1989
Poihipi north of Taupō Wairakei Contact Energy 55 350 1997
Rotokawa north of Taupō Rotokawa Mercury 33 210 1997
Tauhara - Stage 2 north of Taupō Tauhara Contact Energy 152 (up to 174) Unknown 2024
Te Huka (Tauhara Stage 1) north of Taupō Tauhara Contact Energy 23 190 2010
Te Mihi north of Taupō Wairakei Contact Energy 159 1200 (approx) 2014
Wairakei north of Taupō Wairakei Contact Energy 161 1310 1958, 2005

Under construction

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Geothermal development projects include Tauhara stage 2 and Te Huka Unit 3.

Name Location Field Operator Capacity (MW) Expected Commissioning Date
Te Huka Unit 3 north of Taupō Wairakei Contact Energy 51 4th quarter of 2024
Ngatamariki Unit 5 north of Taupō Ngatamariki Mercury 46 4th quarter of 2025

Proposed

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Name Location Field Operator / Owner Capacity (MW) Development Stage
TOPP2 Kawerau, Bay of Plenty Kawerau Eastland Generation 49 Capital raising stage (2023)
Taheke Okere, Bay of Plenty Taheke Eastland Generation / Taheke 8C 35 Consented (2023)
Ngawha Unit 5 near Kaikohe, Northland Ngawha Top Energy 32 Consented

Decommissioned

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Name Location Field Operator Capacity (MW) Annual Generation
(average GWh) 		Commissioned Decommissioned
Kawerau TA3 Kawerau Kawerau Tasman Mill. Later Norske Skog Tasman (NST) 8 Unknown 1966 2004
Kawerau TG1 & TG2 Kawerau Kawerau Bay of Plenty Energy (later Nove Energy) 6.4 35 TG 1989.

TG2 1993

TG1 was decommissioned in 2014. TG2 was decommissioned in 2017.

See also

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References

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  1. ^ a b c d "New Zealand 2023 – Analysis". IEA. Retrieved 2024-03-27.
  2. ^ a b c d "New Zealand 2023 Energy Policy Review" (PDF). International Energy Agency (IEA). 2023.
  3. ^ a b "Steam Clean", e.nz magazine, IPENZ, pp. 13–16, May–June 2008
  4. ^ Geothermal Energy and Electricity Generation (from the New Zealand Energy Efficiency and Conservation Authority website. Accessed 2019-17-06.)
  5. ^ a b c "Geothermal Fields". New Zealand Geothermal Association. Archived from the original on 2 June 2010. Retrieved 2 May 2010.
  6. ^ a b Geothermal Energy and Electricity Generation Archived 2010-06-02 at the Wayback Machine (from the New Zealand Geothermal Association website. Accessed 2013-10-04.)
  7. ^ "Steaming Forward". Time. 8 June 2003. Archived from the original on February 8, 2007. Retrieved 19 June 2008.
  8. ^ "Geothermal Energy Research". GNS Science. Retrieved 15 October 2017.
  9. ^ "Energy Systems Modeling". Industrial Research Limited. Retrieved 19 January 2010.
  10. ^ "Energy Development in Island Nations: New Zealand". Archived from the original on 17 October 2009. Retrieved 2 March 2010.
  11. ^ Mackenzie, A. (2009). Island Escape. e.nz magazine, 10(4), 23-28.
  12. ^ a b Regulatory Settings Archived 2010-05-23 at the Wayback Machine (from the New Zealand Geothermal Association website. Accessed 2010-05-02.)
  13. ^ "Geothermal Energy Regulations 1961". Zealand Parliamentary Counsel Office. Retrieved 16 May 2008.
  14. ^ Resource Management Act Archived 2008-04-30 at the Wayback Machine (from the Ministry for the Environment website. Retrieved 2007-07-31.)

Further reading

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  • Martin, John E, ed. (1991). People, Power and Power Stations: Electric Power Generation in New Zealand 1880 - 1990. Wellington: Bridget Williams Books Ltd and Electricity Corporation of New Zealand. pp. 316 pages. ISBN 0-908912-16-1.
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