Energy

Geothermal energy within New Zealand is predominantly used to provide steam for the generation of electricity.

The Mokai geothermal energy resource is located under the Trust’s land, where hot rock heats water to over 300°C. Deep wells enable the heat energy within the water to be brought to the surface for commercial use.

Tuaropaki Trust controls access to the geothermal energy under its lands and has granted to Tuaropaki Power Company Ltd the right to extract up to 40,000 tonne of geothermal fluids per day. These rights are for a 30-year term, expiring 24th December 2027.

Tuaropaki Power Company Ltd

The Trust's wholly owned subsidiary, Tuaropaki Power Company Limited (TPC) was established in 1994 for the sole purpose of generating and marketing electricity from the Mokai geothermal resource permitted to be used by the resource consents granted by Environment Waikato.

TPC's first 55MWe geothermal power plant, Mokai I, was commissioned in 2000 and consistently performed ahead of initial expectations.

In 2002 the decision was made to build Mokai II, providing an extra 38MWe. TPC was owned 100% by the Trust until 2003 when, as part of the arrangements for the Mokai II development, a quarter share was acquired by business partner, Mighty River Power.

The geothermal resource is now providing more steam and less water, and to use the additional steam a decision was made in 2006 to modify the existing Mokai I steam turbine and acquire an additional Ormat Energy Converter to provide a 17 megawatt increase in capacity.

Total capacity of the Tuaropaki geothermal power station is 110MWe.

Mighty River Power perform operations maintenance of the steamfield, power plant and transmission system, markets the electricity and provides long term price support for the sale of electricity. The contractual arrangements with MRP, including the shareholding, cease in 2027 when 100% ownership reverts to Tuaropaki Trust.