| Title | Superhot geothermal – A net zero window of opportunity for New Zealand? |
|---|---|
| Authors | C. Bromley, A. Heuser, I. Chambefort, M. Palmer, D. Rybalka, B. Carey |
| Year | 2024 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | superhot, supercritical, resource assessment, economics, geothermal generation projection, inventory |
| Abstract | The installed geothermal capacity in New Zealand in 2024 is ~1.2 GWe with production of ~8 TWh /yr supplied onto the grid in 2023. The production supporting this generation infrastructure is all produced from wells shallower than 3.5 km depth, but with significant opportunity for additional energy production by accessing deeper resources. GNS Science, through the MBIE Endeavour Research Programme, Geothermal the Next Generation (GNG), has been considering the deeper opportunity and has developed a Superhot Geothermal Inventory for onshore New Zealand geothermal prospects. Assessment has been undertaken using the United Nations Framework Classification for Resources. Considering only identifiable resource volumes, outside of any regulatory protected geothermal systems, and within the depth range of 3.5 to 6 km, the inventory identifies that there is a possible additional capacity of up to ~3.5 GWe, producing about 29 TWh /yr. An electricity market modelling study, prepared by Castalia Ltd (2023) forecast that superhot geothermal power plants could contribute up to an additional capacity of 2 GWe to the New Zealand grid by 2050. This is a consequence of the significant increase in demand, and hence renewable capacity, forecast to be required as New Zealand transitions to Net Zero carbon emissions. Castalia modelled electricity market conditions out to 2050 and assessed the likely commercialisation date for superhot geothermal power plants. Additional capacity of 1.4 to 2 GWe is robust for superhot geothermal power plants producing electricity even at up to double the costs for conventional geothermal. This is a significant strategic Net Zero opportunity for New Zealand. It should be investigated and evaluated, working towards realising superhot geothermal generation as part of the nation’s energy transition. |