The 550 members of a small Ngati Tahu-owned trust have entered into a 25:75 joint venture with Mighty River Power to build a $450 million 132MW power station using the Rotokawa geothermal field near Taupo in New Zealand.

Ten years ago the Trust, which was then focused on farming had $64,000 in the bank. Since switching to to developing its geothermal field, its assets have grown to $30 million. Trust chief executive, Aroha Campbell, said the new Nga Awa Purua station the return could be $40 million over a decade.

Construction of the station starts next month and will take two years. It will plug into existing transmission lines and eventually produce enough power to supply 100,000 homes. As part of the return to shareholders, the trust hopes to provide health benefits and educational grants and is looking at setting up a charitable trust.