Geothermal Energy & Electricity Generation

Geothermal energy produces about 13% of New Zealand’s electricity supply. Most of New Zealand’s installed geothermal generating capacity of about 750 MWe is situated in the Taupo Volcanic Zone, with another 25 MWe installed at Ngawha in Northland. The temperature and conditions of a particular geothermal reservoir determine which type of generation technology is used: dry steam, flash steam or binary cycle.

When the first generator was commissioned at Wairakei in 1958, it was only the second geothermal plant in the world to begin large-scale commercial operation and the first to exploit a wet (rather than dry steam) geothermal resource. The impetus for the development of Wairakei came in 1947 from severe electricity shortages following two dry years which restricted hydro generation, and a desire by the New Zealand Government for the electricity supply to be independent of imported fuel. New Zealand has recently faced similar situations

There are currently six fields used for geothermal electricity generation, which is dominated by Contact Energy Ltd (a listed company) and Mighty River Power (a State Owned Enterprise). A significant factor in recent geothermal projects has been the high level of commercial participation by Maori-owned enterprises.

Historical Changes in NZ Geothermal Electricity Generation Capacity

StationCapacity (MW)OperationDeveloperComments
Te Ahi O Maui (Kawerau)202018Eastland Group and Kawerau A8D Ahuwhenua TrustFour wells drilled, construction on schedule
Ngawha 3252020Top EnergyFour wells drilled in 2018
Ngawha 4252023Top EnergyPlanning stage
Taheke??Contact & Taheke 8C and the Adjoining Blocks IncThree Exploration wells drilled.
Te ia o Tutea (Taheke)??Mercury, Okere Inc and Ruahine Kuharua IncAgreement for expansion and cooperative development
Misc400By 2025VariousBalance of unspecified projects including late stages of existing developments
* Although Ohaaki still has 114 MWe of plant installed on site, one high pressure turbine is now decommissioned and other turbines operate on restricted duty. The station generates around 45 MWe due to field limitations.


The following table indicates upcoming developments.

President

Andy Bloomer

Term expires 2017
Geothermal Engineering
Past President

Bridget Robson

Term expires 2018
Eland
Vice-President

Shanon Garden

Term expires 2017
Mercury
Treasurer

Kevin McLoughlin

Term expires 2018
Tauhara North No.2 Trust
Secretary

Jane Brotheridge

IGA Rep

Term expires 2018
Jacobs
Rosalind Archer

Term expires 2018
University of Auckland
 John Burnell

Term expires 2019
GNS Science
Stephen Daysh

Term expires 2017
Environmental Management Services
Abbie Dean

Term expires 2018
Contact Energy & WiNG
Boaz Habib

Term expires 2018
Heavy Engineering Research Ass.
Kevin Koorey

Term expires 2017
MB Century
Katherine Luketina

Term expires 2019
Waikato Regional Council
Andrew Rae

Term expires 2019
GNS Science
Paul Siratovich

Term expires 2019
Mercury
Sadiq Zarrouk

IGA Rep

Term expires 2017
University of Auckland