| Title | Combining low grade geothermal heat with heat pumps, an opportunity to decarbonise industrial districts |
|---|---|
| Authors | C. Wells, Y. Carden |
| Year | 2025 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Geoheat, district heating, low temperature geothermal, ground source heat pump, energy security, decarbonizing |
| Abstract | In Aotearoa New Zealand, district heating networks for commercial and industrial applications are notably scarce. Prominent examples, such as Kawerau and He Ahi, leverage site specific high-temperature geothermal resources to support industrial processes. However, the concept of shared thermal energy infrastructure is overlooked, despite its potential to offer significant economies of scale and cost efficiencies for businesses. Low-grade geothermal heat is widely available across Aotearoa New Zealand but remains underutilised, partly due to perceptions of limited applications and its overshadowing by high-temperature systems primarily used for electricity generation. Recent advancements in industrial ground source heat pump (GSHP) technology are shifting this paradigm. Modern GSHPs can now deliver process heat at temperatures up to 160°C, with prototypes reaching 180°C and expectations of achieving 200°C within this decade. These developments position low-grade geothermal resources as viable and valuable for a broader range of industrial applications. The high capital investment required for individual GSHP systems can be a barrier to adoption. This paper proposes that district scale low-grade geothermal infrastructure could mitigate these costs, thus maximising uptake and impact. There is opportunity for public investment in such infrastructure, as it supports the electric transition being promoted by the Government by reducing reliance on the national electricity grid, particularly during peak demand periods. A private model, where heat is supplied as a service to industrial customers, is equally viable and has been commercially implemented internationally. This paper will explore regions where district geoheat presents the most compelling potential and examine the roles that both the geothermal community and government can play in facilitating its development. |