Geothermal energy is an important low-carbon source of electricity (~1000 MWe) and heat (~8 PJ/year) for Aotearoa New Zealand. The high capacity factors of New Zealand’s geothermal power plants allow for base load firming in the electricity grid. Additionally, direct-use heat applications range from timber-drying to space heating. However, as valuable as electricity and direct heat are for domestic decarbonisation, there is growing potential for New Zealand to contribute to international markets with low-carbon exports and services.

Three emerging technologies with strong synergies with geothermal are: (1) green hydrogen, (2) brine-derived lithium and (3) atmospheric CO2 removal. In this study, we evaluate the potential of each technology against a future geothermal generation stack, currently unbuilt but expected to come online between 2030 and 2050. The estimated potential of these fields is 735 MWe. All three technologies have export pathways, albeit immature, that may help geothermal developers find favourable market applications more easily.

In addition to parasitic load, we assess the secondary resources required to achieve this value-stacking. This includes the water load for green hydrogen production and the low-grade heat for direct air capture (DAC). Finally, we assess the cost of these products and compare them to conventional electricity generation. We estimate potential annual production of 60 kt of green hydrogen, 1.2 kt of lithium and 4 Mt of CO2 removed with possible revenues of (NZD) $300, $16 and $700 million per year respectively.