Mighty River Power has temporarily shut its geothermal power station near Taupo to work on its steam turbine, less than four years after it was first started.
The Nga Awa Purua station will be out of action for one or two weeks while the work is done, the company said.
The power station is jointly owned by Mighty River Power with 65 per cent and Tauhara North No.2 Trust with 35 per cent.
The work and eventual replacement of turbine blades will cost the joint venture partners about $15 million in the 2015 financial year.
The plant was completed in early 2010 and can produce 138 megawatts of power.
Joint Venture chairman, William Meek, said that during a planned outage for routine maintenance, inspections found that the turbine blades were being affected by geothermal fluids used to power the plant. The turbine was modified to allow ongoing operation, reducing operating capacity to about 95 per cent.
"This shut[down] means we can open up the turbine so that we can properly assess the issue to increase reliability of the plant through until permanent repairs can be made in about 15-18 months," he said.
Meek said the maintenance outage would not have a material financial impact, with revenue losses mitigated by wholesale market conditions.
- Fairfax Media