The shallow geothermal energy potential in Auckland: An exploratory study

Abstract

Shallow geothermal energy offers a clean, widely applicable, and cost-effective resource. A practical field assessment of this resource is essential for designing a subsurface heat extraction system. A 20 m monitoring well was drilled in Takanini, Auckland and installed with 15 temperature sensors to evaluate its shallow geothermal potential over 12 months.
Temperature profiles exhibited clear seasonal and diurnal variations near the surface, stabilising at approximately 18 °C below 8 m depth. These observations suggest that Auckland's subsurface thermal regime is richer than that of comparable temperate cities such as Melbourne and London. Concurrent monitoring of domestic water temperatures supports preliminary feasibility for geothermal?heated water supply. Ongoing field experiments will further assess the performance of borehole heat exchangers under local geological and climatic conditions. This research will effectively promote the development of sustainable geothermal energy in New Zealand, especially in the broad application of shallow geothermal heat.