First supercritical geothermal site chosen

Land within Rotokawa Geothermal Reservoir in the Taupō Volcanic Zone has been selected as a preferred site for New Zealand's first supercritical geothermal exploration, with design work already underway to develop the first well, Regional Development Minister Shane Jones says.

"This early-stage exploration could help prove the viability of supercritical geothermal energy, which has the potential to deliver several times the power output of conventional geothermal wells. This groundbreaking work could be a game changer for securing New Zealand's future energy needs," Mr Jones says.

The Rotokawa site was selected following extensive geological and geophysical study by Earth Sciences New Zealand, and risk assessments to confirm its suitability.

"Tauhara North No.2 Trust is guardian of the Rotokawa geothermal resources and have deep cultural and historical connection to the area. Its people have used geothermal energy for cooking, bathing, and healing for generations," Mr Jones says.

A Memorandum of Understanding has been signed between Tauhara North No.2 Trust, the Ministry of Business, Innovation and Employment, and Mercury NZ which operates the Rotokawa geothermal power station, to explore the potential of supercritical geothermal energy at the site. Earth Sciences NZ is contributing technical and scientific expertise.

As part of the work, a multi-disciplinary design team comprising local and international experts, is also being assembled to lead work across regulatory approvals, design, risk assessment, geoscientific modelling, engineering, procurement, drilling and asset management.

The Coalition Government has committed up to $60 million from the Regional Infrastructure Fund to support the development of the first well, with plans for two additional wells as part of a broader programme.

The first phases of the project include pre-feasibility work studies, well design, development of a business case and validation of the preferred site. Drilling is expected to begin in 18-24 months.

"Three exploratory wells are the minimum needed to understand the energy resource. New Zealand has pioneered geothermal development in the past with government-led geothermal exploration during 1950s and 1970s. During this time, more than 40 wells were drilled across the motu to explore geothermal resources," Mr Jones says.

"Drilling into supercritical zones means going 1km-3km deeper into the Earth and managing higher pressures and temperatures than current conventional generation. This is one of the most technically demanding frontiers in geothermal technologies and science," Mr Jones says.

"Safely converting and commercialising supercritical geothermal energy is the next step. The Government is backing this groundbreaking project which aims to unlock transformative, clean, renewable energy over the long term to strengthen our energy security and be transformative for the country and internationally," Mr Jones says.