Geothermal Power Plants in New Zealand
Kawerau New
Location: Bay of Plenty
Operator: Mighty River Power Co
Configuration: 1 X 90 MW
Operation: 2008
T/G supplier: Fuji
EPC: Sumitomo, Hawkins Construction
Quick facts: This was New Zealand's largest geothermal project in 20yrs and cost NZ$300mn. Construction began in Jan 2007 and the plant was connected in Aug 2008, under budget and about 6wks ahead of schedule. The generator is connected to a 6-well steam field by an 8km pipeline. This was the world's largest double-flash geothermal generating unit at completion. Photograph courtesy of Mighty River Power
Posted 18 Feb 2009
McLachlan (Poihipi)
Location: Auckland
Operator: Contact Energy
Configuration: 1 X 55 MW
Operation: 1996
T/G supplier: Fuji
EPC: SMEC-HGEM
Quick facts: In 1994, Mercury Energy took a 51% stake in a joint venture called Mercury Geotherm which built this geothermal plant about 5km from Taupo. The other partner was the family of landowner Alistair McLachlan, which contributed land and geothermal energy rights to the project. The unit was officially opened by the Energy Minister, the Hon Max Bradford on 30 Aug 1997. The T/G set was built in 1987 and originally intended for The Geysers, but it was never installed. After market deregulation, it became increasingly uneconomic for Mercury to purchase plant output at the original rates. Mercury Energy wrote off about NZ$50mn on its investment in the plant and, in Dec 1998, put the station in receivership with Auckland accounting firm Smith Chilcott. It was bought by Contact Energy in 2000.

Photograph by David Neale
Posted 25 Jan 2004

Mokai
Location: Auckland
Operator: Mighty River Power Co
Configuration: 1 X 32 MW, 1 X 19 MW, 10 X 6 MW binary
Operation: 2000-2007
T/G supplier: GE, MHI, Ormat
EPC: Ormat
Quick facts: The Mokai geothermal field is 20km north of Taupo. The field has some of the hottest geothermal wells in New Zealand with downhole temperatures of up to 326°C recorded. The high reservoir temperatures mean that wells tend to produce high steam content fluids with high chloride and silica content. The first-phase Mokai power station was the first in New Zealand to be fully owned by a Maori trust (the Tuaropaki Trust which subsequently placed assets in the Tuaropaki Power Co), with Mighty River Power contracted for O&M. All condensate and cooled brine is reinjected. A large geothermally heated greenhouse complex has been developed nearby. Photograph courtesy of Ormat
Re-posted 26 Mar 2011
Ngawha
Location: West Coast
Operator: Top Energy Ltd
Configuration: 2 X 6 MW, 1 X 17 MW binary
Operation: 1998-2008
T/G supplier: Ormat
EPC: Ormat, SMEC
Quick facts: In Jan 2007, Ormat received a $20mn EPC contract for a 17-MW extension to the Ngawha plant. The site is near Ngawha Springs, Akaroa County where Top Energy has been operating a 12-MW Ormat binary plant since Jun 1998. The Tai Tokerau Maori Trust Board is a co-owner of the facility. The new plant went online in Oct 2008 and now has a total of 4 energy converter units. In total, the station provides about 70% of the electricity used in New Zealand’s Far North. The Ngawha field is a large, but challenging geothermal resource with relatively low heat content and high levels of dissolved material and gases. Photograph courtesy of Ormat
Posted 26 Mar 2011
Ohaaki
Location: Auckland
Operator: Contact Energy Ltd
Configuration: 2 X 11 MW, 2 X 50 MW
Operation: 1989
T/G supplier: EE, MHI, GEC
Quick facts: Production wells at Ohaaki are, on average, 1.2km deep and reach water at temperatures up to 280°C. The most distinctive feature at Ohaaki is the 105m cooling tower.

Photograph by Andrew McCabe
Posted 13 Nov 2004

Rotokawa
Location: Auckland
Operator: Mighty River Power Co
Configuration: 1 X 14.5 MW BP, 3 X 4 MW binary
Operation: 1997
T/G supplier: GE, Ormat
EPC: Ormat
Quick facts: The first studies at Rotokawa date to 1953 and the power station was commissioned in Sep 1997. It was purchased by Mighty River Power in 2000. In late 2002, a 20% expansion of Rotokawa was commissioned to further extend the operational improvements achieved in 2001 and capacity increased to 34MW. The generation plant is owned by Mighty River Power and the steams wells are owned by Rotokawa Joint Venture Ltd, partially owned by the Tauhara North No. 2 Trust. The Nga Awa Purua plant was later developed on the Rotokawa field. Photograph courtesy of Mighty River Power Co
Posted 7 Aug 2010
Taonga
Location: Auckland
Operator: Mighty River Power Co
Configuration: 1 X 140 MW
Operation: 2010
T/G supplier: Fuji
EPC: Sumitomo, Hawkins Construction
Quick facts: Formerly named Nga Awa Purua, this NZ$430mn geothermal power station is the second development by Mighty River Power in partnership with the Tauhara North No 2 Trust. It is close to the existing Rotokawa geothermal power station and was connected into existing 220kv transmission lines running over the field. At completion, Nga Awa Purua had the largest, single-shaft geothermal turbine in the world. It was officially opened by Prime Minister John Key in front of 700 guests on 15 May 2010. Photograph courtesy of Mighty River Power Co
Posted 7 Aug 2010<
Te Huka
Location: Auckland
Operator: ContactEnergy Ltd
Configuration: 2 X 13 MW binary
Operation: 2010
T/G supplier: Ormat
EPC: Ormat
Quick facts: In Jul 2008, Contact Energy contracted Ormat to supply this geothermal power station on Centennial Drive in Taupo. At that point, the necessary wells had already been drilled. In May 2010, the NZ$100mn project was completed 3wks ahead of schedule. The plant was the first built on the Tauhara steamfield. Photograph courtesy of Ormat
Posted 26 Mar 2011
Te Mihi
Location: Auckland
Operator: Contact Energy Ltd
Configuration: 2 X 83 MW
Operation: 2014
T/G supplier: Toshiba
EPC: SNC-Lavalin, Parsons Brinckerhoff, McConnell Dowell
Quick facts: In Aug 2007, Contact Energy filed consent applications for the Te Mihi project north of Taupo. In Sep 2008, the Environment Ministry approved the application and the GPP was commissioned on 1 May 2014 at a cost of NZ$623mn. Peak construction staffing was 600 people and over 3.1mn manhours were expended on the project. The work was complicated by being undertaken in a live steam field already serving the Wairakei plant.

Photograph courtesy of Contact Energy Ltd
Posted 6 May 2015

   
Wairakei
Location: Auckland
Operator: Contact Energy Ltd
Configuration: 6 X 11 MW, 3 X 30 MW, 2 X 8 MW
Operation: 1959-2005
T/G supplier: GEC, Ormat
Quick facts: Wairakei is situated above a large geothermal resource containing water at temperatures up to 240°C. Currently, about 5,000 tph of fluid is taken from the reservoir, of which 1,500 tph is steam-equivalent and 3,500 tph is hot water. Dry steam is also taken from shallow production wells (up to 500m depth) and used directly. The once through cooling system uses water from the adjacent Waikato River. Outgases are released via gas stacks on the power station roof while hot geothermal water is discharged into a system of drains leading to the Waikato River or is re-injected. Two binary sets commissioned in 2005 increased generation by 10% and utilized heat energy previously untapped.

Photograph courtesy of Origin Energy Ltd
Re-posted 27 Jul 2008

Abbreviations

Data: industcards, Platts UDI World Electric Power Plants Data Base

Updated 06-May-2015

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