Top Energy kicks off commercial operation of 32 MW Ngawha 3 geothermal power plant

Top Energy kicks off commercial operation of 32 MW Ngawha 3 geothermal power plant Ngawha 3 geothermal power plant, New Zealand (source: Top Energy)
Alexander Richter 27 Jan 2021

NZ-based utility Top Energy has successfully commissioned the Ngawha geothermal power plant in New Zealand, adding 32 MW in power generation capacity to its portfolio and New Zealand's geothermal market.

Community owned Top Energy in New Zealand, has announced the commissioning of the Ngawha geothermal power station (OEC4) after an intensive three-year construction, well drilling and plant assembly programme. Despite delays due to COVID-19 the power station was completed six months earlier than planned.

A testament to the hard work the company and its contractors United Civil Construction, Iceland Drilling, Culham Engineering and Israel firm Ormat. One of the largest projects undertaken in Northland, Ngawha power station secures an independent, renewable and affordable power supply, ending the region’s reliance on the National Grid and electricity being transported from the south.

The new station will generate 32MW of power, considerably more than the 25MW generated by the two existing power stations combined.

The total output will supply the Far North’s electricity demand 95% of the year, with excess power exported to the rest of Northland through the National Grid. Now that OEC4 is generating electricity, Top Energy starts a three year period of monitoring the geothermal field.

This is to ensure that the field performs in a similar way to the model prepared by GNS Science in support of the resource consent application. OEC5, the next 32MW station, is already consented, subject to confirmation of the performance of the field but will only proceed if an acceptable business case can be developed.

In the coming years the company will monitor market conditions to determine whether OEC5 should proceed. The OEC5 investment will also be subject to a Major Transaction Approval by Top Energy Consumer Trust.

Key timeframe:

  • Project kick off in July 2017 with the final resource consent granted
  • Major approval by Top Energy Consumer Trust and Top Energy Board and early start on the site in oOctober 2017.
  • December 2017 – contracts awarded for the well drilling (Iceland Drilling Company) and for the power station construction (Ormat Technologies)
  • January to April 2018 – Construction of drilling pad, water storage and settlement ponds, and first stage of power station complete and drilling start
  • September-October 2018 – Viability of geothermal resources determined
  • January-Sept. 2019 – Well drilling and power station platform construction completed. Construction of control room, office, substation and transmission line begins
  • Oct. 2019- Aug. 2020 – Construction of power station, pipelines and electricity transmission system continues
  • Dec. 2019 – New Control room operational
  • August 2020 – Commissioning and testing of transmission line and power station begins
  • December 2020 – Power station is live

Source: Top Energy/ project website