Ngatamariki is a geothermal power station commissioned in 2013 and operated by Mercury Energy. It is located approximately 17 km north east of Taupō and was constructed well under the budget of $475 million.[1][2][3]
The field was initially explored by the Crown in 1985-86, with the wells NM1, NM2, NM3, and NM4 drilled to 1300m, 2403m, 2194m, and 2749m respectively.[4] NM4 was the first well in New Zealand to encounter a pluton, at a depth of almost 2400m. Mighty River Power undertook further drilling in 2008-09, with wells NM5, NM6, and NM7 drilled to depths of 2997m, 3398m, 2963m respectively.[5] Resource consents for further development were granted in May 2010.[6]
Work at the geothermal field site on the first stage of the plant (82 MW) commenced in July 2011[7] and the plant became operational in September, 2013, one month later than scheduled.[2][8] The power station is a binary plant, supplied under an EPC contract by Ormat.[9] A 220,000-volt power line connects Ngatamariki to Mercury's Nga Awa Purua Power Station, where electricity from both stations is injected into Transpower's national grid.
The Ngatamariki Geothermal site consists of 7 geothermal wells (3 production and 4 re-injection). In addition to the main geothermal wells, there are 21 sentinel and monitoring wells, to depths of 1,500m.[1]
^Urzúa-Monsalve, Luis Alejandro (2008). Integration of a preliminary one-dimensional MT analysis with geology and geochemistry in a conceptual model of the Ngatamariki geothermal field (M.Sc.). University of Auckland.
^O'Brien, Jeremy Mark (2010). Hydrogeochemical Characteristics of the Ngatamariki Geothermal Field and a Comparison with the Orakei Korako Thermal Area, Taupo Volcanic Zone, New Zealand (M.Sc.). University of Canterbury.