Power generator wins testing rights

The Environment Court has approved a six-month trial to determine the effects of increased fluid draw-off from the Ngawha geothermal field on pressure in the field's underground reservoir.

Consent for testing and measuring a pressure mitigation process follows an appeal by Ngawha Geothermal to the Environment Court.

The company, a subsidiary of Far North-based lines network company Top Energy, failed last year to win approval from two Northland councils to increase the amount of geothermal fluid an expanded power generation plant would need to draw from and re-inject into the field.

The companies wanted to expand output from their existing Ngawha geothermal power station, east of Kaikohe, from the current 10MW to 25MW.

A joint council consent authority did not agree with Ngawha Geothermal's findings showing no significant effects on the field from an increased draw-off, or a proposed scheme to support reservoir pressure if it was shown to have changed in the future.

The councils turned down the scheme for the expanded plant but last month, in its appeal to the Environment Court, the company successfully asked for three key consents to be granted for a six-month trial period.

This would allow the effectiveness of the reservoir pressure mitigation proposal in the geothermal field to be demonstrated and measured.

Ngawha Geothermal will start testing the process at the end of June. It will inject additional water into the geothermal field's reservoir to demonstrate effects on pressure.

- NZPA