This update is for those who’ve been involved – or expressed interest – in this pioneering initiative.
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Pānui
New Zealand’s supercritical geothermal project
Nau mai, haere mai – welcome to our pānui
Before we begin, I want to acknowledge the passing of Tā Tumu Te Heuheu, Te Ariki o Ngāti Tūwharetoa. A leader of immense mana and strength, his unwavering commitment to Ngāti Tūwharetoa and advocacy for kaitiakitanga and cultural heritage leave an enduring legacy. We extend our heartfelt aroha to his whānau and Ngāti Tūwharetoa at this time of great loss.
Hon Tim Groser
As Chair of the Supercritical Geothermal Governance Group, I’m delighted to share our first pānui (newsletter) with you.
This update is for those who’ve been involved – or expressed interest – in this pioneering initiative. Please feel free to share it widely so others can opt in. If you’d prefer not to receive future updates, click on the ‘unsubscribe’ link at the end of the email.
The supercritical geothermal project is a groundbreaking cross-discipline, cross-border, pioneering technological and scientific endeavour, and it’s happening in New Zealand thanks to NZ$60 million ring-fenced from the Government’s Regional Infrastructure Fund, which was announced in November 2024. Since then, we’ve made exciting progress that we’ll share with you here and in future occasional pānui.
At the heart of this project is the Rotokawa geothermal field, where the partnership between Tauhara North No.2 Trust and Mercury NZ has already delivered world-class geothermal developments. Their joint venture experience and commitment to sustainable practices provide a strong foundation for this next frontier in geothermal innovation. This collaboration ensures that the project not only advances global science but also reflects local values and aspirations.
Ensuring the continued protection of New Zealand’s natural geothermal resources as we move forward with this work is top priority. The international exploratory work on supercritical geothermal to date, along with the tried-and-true processes we use to monitor our conventional geothermal energy development and production, gives the team great confidence in their ability to maintain the conditions of our natural geothermal resources as we work to unlock this great potential energy source.
We are fortunate to draw on the knowledge and skills of local and international scientists, engineers, businesses, and institutions alongside the deep geothermal expertise of Tauhara North No.2 Trust and Mercury NZ. Together, we are building on decades of geothermal leadership and creating opportunities that will benefit New Zealand and the world.
Nāku noa, nā
Tim Groser
Chair, Supercritical Geothermal Governance Group
Introducing ‘supercritical geothermal’
Drilling depths to be attempted in the SCGTP compared to conventional geothermal drilling. Image: Earth Sciences New Zealand (ESNZ)
Supercritical geothermal energy comes from water heated by magma deep beneath the Earth’s crust. Scientists and engineers interchangeably use the three terms: superdeep, supercritical and superhot.
At over 400°C and extreme pressure, the water enters a ‘supercritical’ state – neither liquid nor gas, but something in between that holds up to three times more energy than conventional geothermal fluids.
If successful, this technology could unlock one of the most powerful renewable energy sources on the planet – right here in New Zealand.
Rotokawa chosen for first well
The Rotokawa Geothermal field was selected following a five-year research programme by Earth Sciences New Zealand (ESNZ) (formerly Geological and Nuclear Sciences, or GNS). Rotokawa stood out as the most favourable location for two main reasons.
Firstly, the Rotokawa field has been producing geothermal energy for 28 years so there is extensive data and understanding of the geothermal reservoir and geology. Secondly, ESNZ’s research concluded that the shallowness of the Earth’s crust under Rotokawa provided the best chance of success of hitting the supercritical resource.
Ngā Tamariki Geothermal Station, Taupō
Why New Zealand?
New Zealand has the science, the geology, the experience, and the relationships to succeed.
We’re a global leader: Due to our long history in geothermal use and generation we already have some of the very best infrastructure, practical experience, and expertise in the world. New Zealand’s approach is committed to environmental stewardship, cultural integrity, and technical excellence. Our programme is designed to be inclusive, resilient, and globally relevant.
Our natural advantage: New Zealand has a distinct natural advantage – our uniquely accessible, shallow and hot geothermal landscape in the Taupō Volcanic Zone may well be the best place on Earth to unlock the power of supercritical geothermal resource.
The exploratory supercritical geothermal work that the New Zealand Government is now embarking on, could unlock the ability to generate limitless, clean, baseload energy from our supercritical geothermal resource, powering our communities and industries for generations to come.
Ngā Tamariki Power Station. Photo: Mercury NZ
Why now?
Increased Demand: New Zealand’s electricity demand is forecast to grow 20% by 2037 and 50% by 2050, driven by population growth, AI, and the electrification of transport and industry. To meet this demand while achieving our net-zero carbon goals, we need more clean, renewable, reliable energy.
The weather-dependent nature of our other renewable energy sources – hydro, solar and wind – means geothermal, which stays hot around the clock, has an important role. Unlocking our supercritical geothermal resource could dramatically increase our reliable baseload and prove to be the solution we’re looking for.
International Momentum: We’re seeing massive momentum in superhot geothermal energy innovation and development – with the International Energy Agency envisioning a trillion-dollar global investment in geothermal energy by 2035. Now is the right time for New Zealand to step into the supercritical geothermal space – harnessing and building on foundational research work in Japan and exploratory work in Iceland.
Today we face a high-value opportunity to position New Zealand at the frontier of geothermal research and development and attract international investment.
Castalia’s economic analysis found that supercritical geothermal could deliver up to 30,000GWh each year – equating to a multi-billion-dollar industry for New Zealand.
Sampling on Taupō Volcanic Zone. Photo: Earth Sciences NZ
Balancing pace with precision
While pace is important, we must also ensure we get the technology right. That’s why we are collaborating with leading experts both locally and internationally. This partnership brings together world-class scientific, engineering, and geothermal expertise to design and validate every step of the process. By combining global best practice with local knowledge, we can move quickly without compromising safety, sustainability, or technical excellence.
Iceland is also a supercritical geothermal pioneer. Photo: wirestock on Freepik
Iceland/NZ agree to collaborate
Iceland and New Zealand have sealed their long-standing shared interest and expertise on supercritical geothermal innovation by signing a formal collaboration agreement at COP30 in Brazil.
The agreement covers joint work and research, industry workshops, and academic exchanges, and will focus on superhot and supercritical geothermal systems and technologies that have the potential to revolutionise global energy supply.
Geothermal Rising 2025 in Reno
Last month, Regional Development Minister and Resources Minister Shane Jones led a small delegation from the supercritical geothermal project to attend one of the world’s largest geothermal conferences Geothermal Rising 2025, in Reno, Nevada.
Their mission? To spread the word about New Zealand’s geothermal credentials and generate investor interest in partnering in our ground-breaking exploration of supercritical geothermal.
Deep geothermal project experts announced
Stanford University earth science and engineering expert Professor Roland N Horne (pictured) will chair an international review panel for the supercritical geothermal project, the Government announced in November 2025. The panel will review the well design and project details, and provide advice on latest international products and technologies. Professor Horne will be joined on the panel by geologist Dr Omar Friðleifsson, well engineer Kristinn Ingason, and geochemist Dr Darrell Gallup.
Next steps
This is a long-term project with several key stages. With our experts on board, we’re working on the first phase: validating the feasibility of the Rotokawa site, and designing the well and equipment needed for withstanding the extreme temperatures and pressures encountered at supercritical depths.
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