Contact Energy's $100 million geothermal power station Tauhara One, near Taupo, has been finished three weeks ahead of schedule.
Contact managing director David Baldwin today said the 23-megawatt (MW) station, which would provide enough baseload renewable energy for about 23,000 homes, was also finished under budget.
It was the first part in a $600m investment programme by the company to be finished.
Other parts of the programme are a $250m 200MW gas-fired fast-start peaking power station at Stratford, in Taranaki, and the $250m Ahuroa gas storage facility in the same region.
Construction of the Stratford station was due to be finished by the end of May, when commissioning would start, Baldwin said.
The Ahuroa storage project was on track to be completed by the end of 2010.
Contact is seeking consents for a 250MW Tauhara Two geothermal power station through a board of inquiry process and advancing development of its consented 220MW Te Mihi power station.
It said it expected exploration of the Taheke geothermal resource to start soon, in conjunction with joint venture partner the Taheke 8C Incorporation.