Kawerau Geothermal

Generation from an environmentally friendly renewable resource

The Kawerau Geothermal Stations tap into a renewable energy source located in the geothermally active Kawerau region. These revolutionary plants, located at Kawerau on opposite banks of the Tarawera River, are owned and operated by Todd Energy via our retail and generation business, Bay of Plenty Energy.

The plants provide an embedded form of generation within the BoPE network. This not only saves energy transmission losses but also provides energy from a renewable source with significant environmental benefits to some 5,300 residential customers.

TOI (also known as TG1), the first of two developments, was commissioned in 1989 at a cost of $4.3 million and generates 2.56 MW of electricity. TOI (an acronym for Tarawera ORMAT Installation, but also in honour of the great Ngati Awa explorer) has two turbines, each driving a 1.3 MW generator.

TG2, or "Tarawera Geothermal 2" was commissioned in 1993 following on from the success of the TOI scheme. The $5.4 million project uses two turbines to drive a single 3.8 MW generator.

Benefits

The TOI and TG2 generating units produce little noise or visual impact and use an energy source which would otherwise be wasted. The system passes geothermal fluid through a heat exchanger, heating the hydrocarbon motive fluid used to drive the turbines. This fluid is completely contained within a closed loop system so once it has been through the turbines it is cooled and passed through the heat exchanger to begin the cycle again.

The Tarawera River also benefits from the reduced temperature of the geothermal fluid discharged from the plants that would otherwise be discharged direct from the bores, lowering river temperatures and increasing the oxygen content and life bearing capacity of the river.

Generating Plant

Operation of the generating units is automated via a computer control system at Bay of Plenty Energy's Whakatane office.