GEOTHERMAL EXPLORATION
Mercury is exploring an expansion of its geothermal field at its Ngā Tamariki site near Taupō
Mercury is building on more than two decades of geothermal experience with a significant programme of exploration, appraisal and development designed to support New Zealand's growing demand for reliable, renewable electricity.
As part of its long-term growth strategy, Mercury has identified up to 5TWh of potential geothermal generation opportunities in the central North Island.
Around 2.5TWh is already under development, with about 1TWh entering feasibility assessment and targeted for first generation from 2030.
To advance these opportunities, Mercury has committed $75 million over the 2027 and 2028 financial years to support a geothermal appraisal drilling programme.
This investment will help improve understanding of key geothermal reservoirs, confirm future generation potential and support informed investment decisions before major development capital is committed.
A proposed expansion at the Rotokawa geothermal field in the Central North Island is also being explored.
The new projects
The programme includes appraisal drilling at Ngā Tamariki and Rotokawa geothermal fields, two of Mercury's highest-priority geothermal growth opportunities.
At Ngā Tamariki, Mercury is investigating an expansion that could add up to 75MW of new generation capacity, producing about 620GWh of renewable electricity each year.
This is additional to the expansion project completed at Ngā Tamariki from 2024-2026.
At Rotokawa, a proposed expansion could deliver an additional 50MW of capacity and around 420GWh of annual generation.
Both projects entered the feasibility stage in 2026 and will undergo further technical assessment, appraisal drilling, and consenting before any final investment decisions are made.
Opportunity for growth
Mercury's geothermal strategy is based on a staged and disciplined development approach.
Exploration and appraisal activities help reduce technical risk, improve confidence in resource performance, and ensure that future investments are aligned with customer demand and market needs.
The company's deep geothermal expertise, strong partnerships with iwi and landowners provide a strong platform for future growth.
Superhot geothermal
Alongside conventional geothermal development, Mercury is also helping explore the next generation of geothermal technologies.
This includes participation in New Zealand's emerging superhot geothermal research programme at the Rotokawa geothermal field, which has received government support and could unlock new opportunities for geothermal energy in the decades ahead.
By investing in exploration today, Mercury is creating future options for new renewable generation, supporting energy security, economic growth and New Zealand's transition to a more sustainable energy system.
Related Links
Mercury - Investor Day 2026 presentation summary - May 2026
NZX - Mercury scaling geothermal platform -14 May 2026
Media Coverage
ThinkGeoEnergy - Mercury to expand capacity of operating geothermal fields -14 May 2026
BusinessDesk - Mercury scaling geothermal platform -14 May 2026