Te Mihi Geothermal Power Project - from Inception to Execution

Abstract

The inception of the 166 MW Te Mihi geothermal power project followed the successful re-consenting of Wairakei power station in 2007. The configuration and construction of the Te Mihi power station in the west of the field optimised the use of the geothermal resource and helps to address some of the additional resource consent conditions relating to the continued operation of the Wairakei power station. Although the existing steamfield and any extension would be able to supply steam for electricity generation for many more years, any additional re-consenting of the Wairakei station in its existing location and current, or even altered, configuration was considered to be difficult beyond its current consent expiry in 2026. The Te Mihi geothermal power station is a staged replacement of the existing Wairakei A and B power station. The Te Mihi power station is currently one of the single biggest geothermal developments in the world. This paper discusses some of the challenges relating to development, consenting, design and construction of this significant project.