A research team led by Associate Professor Sadiq J. Zarrouk, co-director of the University of Auckland’s Geothermal Institute, has started drilling under Auckland, New Zealand, to explore how geothermal heat can support heating systems for homes and businesses. Partnering with Drill Force NZ Ltd, a water well drilling company, the team is gathering temperature data from a well in Takanini to determine if geothermal energy can lower water heating costs.

Associate Professor Sadiq J. Zarrouk, co-director of the Geothermal Institute, is leading a research team studying the use of geothermal for heating in Auckland, New Zealand

The project aims to harness geothermal heat as a sustainable energy source for buildings. Zarrouk estimates that households could save up to $20 monthly on water heating expenses, based on typical costs. He explained the project’s goal: “The long-term vision is to make the technology low-cost and simple to implement in both new builds and existing buildings. The goal is to see it adopted widely as a clean, cost-effective energy solution.”

The system involves drilling a shallow well near a property and running a water pipe through it. As water passes through the pipe, it absorbs natural ground heat, raising its temperature slightly. This reduces the electricity needed to heat water further, lowering energy consumption and utility bills. A phase-change material is used to store and distribute thermal energy efficiently, helping manage demand during peak times.

The team has equipped the Takanini well with 15 sensors to track temperature variations up to 20 meters underground. Using machine learning, they are analyzing this data to improve the design of a second well, planned for drilling in the coming months. Both wells will be monitored over the next year to study seasonal temperature patterns. If the results are encouraging, the team will install heat extraction systems to test the technology further.

Zarrouk highlighted the project’s potential impact: “As the first study of its kind in Aotearoa New Zealand, this research has the potential to change the country’s energy use, paving the way for more sustainable and affordable heating options. If successful, the findings could provide long-term scientific and practical benefits, reducing reliance on traditional power sources.”

This initiative could establish a model for affordable, eco-friendly heating, offering a practical way to integrate geothermal energy into everyday use while supporting New Zealand’s sustainability goals.