Introduction to Wairakei

The Western Borefield currently provides 50% of the steam used to generate Wairakei’s electricity. Image: Heurisko Ltd.

The Wairakei Power Station is owned and operated by Contact Energy Limited. Contact Energy produce 25% of NZ’s electricity. The station is an important national generator of electricity. The crown owns the geothermal resource itself. The power station is situated 7km North of Taupo township, and is of particular interest because it:

  • was the first geothermal plant in the world to use very hot water as the source of steam used to drive the turbines
  • produces 1550 GWh of electricity per annum, which is enough to supply Taupo, Rotorua, Napier and Hamilton
  • produces 4.3% of NZ’s electricity production
  • is an important ‘base load’ station
  • has run at better than 90% of maximum output since the 1960’s
  • has an efficiency of converting heat energy to electrical energy of 37%, which is comparable to newer geothermal plants around the world. (Some of this efficiency is due to the use of the very cold Waikato River water in the condensers.)
Summary
Area of steam field 25 sq km
Production wells 54
Re-injection wells 9
Monitor wells or unused wells 70
Average depth of wells 600 m