The Ohaaki Power Station is a geothermal power station owned and operated by Contact Energy. A distinctive feature of this power station is the 105 m high natural draft

cooling tower A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a water stream to a lower temperature. Cooling towers may either use the evaporation of water to remove process heat an ...

, the only one of its kind in New Zealand. Although initially constructed to generate 104 MW, decline in the steamfield has meant maximum net capacity is about 65 MW with an annual output of around 400 GWh pa. There are currently three turbines in operation. One smaller turbine runs off high pressure steam which then backfeeds into the main intermediate pressure system that feeds the two main units. Condensers on the back end of the main turbines are fed cooled water from the cooling tower to condense the steam back into water. Additional condensate gained in this process is reinjected back into the ground. Geothermal

In 2013, the

Waikato Regional Council Waikato () is a local government region of the upper North Island of New Zealand. It covers the Waikato District, Waipa District, Matamata-Piako District, South Waikato District and Hamilton City, as well as Hauraki, Coromandel Peninsula ...

granted resource consents for a term of 35 years and for a take of 40,000 tonnes per day of geothermal fluid.

Ohaaki Marae

The plant is located adjacent to the Ohaaki Marae ( Ngāti Tahu) on the banks of the

Waikato River The Waikato River is the longest river in New Zealand, running for through the North Island. It rises on the eastern slopes of Mount Ruapehu, joining the Tongariro River system and flowing through Lake Taupō, New Zealand's largest lake. It th ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...

. Gradual sinking of the marae has been attributed to draw-off of geothermal fluids by the power station. The area of the marae is sinking approximately 170mm a year. In the 1960s, the marae was moved to its present location because the previous site was flooded when the dam for the

Ohakuri Power Station Ohakuri is a dam and hydroelectric power station on the Waikato River, central North Island, New Zealand, midway between Taupo, Rotorua and Hamilton. Its dam is about upstream of the Atiamuri Dam. It was commissioned in 1961 and construc ...

was filled.

Ohaaki Marae

References

Further reading