Carey, B.S.; Alcaraz, S.A.; Wells, C.; Carden, Y.; Moore, G. 2024 Regional energy transition accelerator – Bay of Plenty – geothermal energy assessment. Lower Hutt, N.Z.: GNS Science. GNS Science report 2024/02. 74 p.; doi: 10.21420/5WW0-J087
Abstract
The Regional Energy Transition Accelerator (RETA) project driven by the Energy Efficiency and Conservation Authority (EECA) aims to develop an understanding of what is needed to decarbonise each region in New Zealand. The objective is to develop a well-informed and coordinated approach for regional decarbonisation by understanding unique region-specific opportunities and barriers when developing regional energy transition roadmaps. It is EECA’s intention to make available the information required to optimise the choice of sustainable energy options in the transition away from fossil fuels. The scope of this work is a geothermal assessment specific to the broader Bay of Plenty (BOP) region. The region is known for its natural geothermal phenomena like hot springs, geysers and boiling mud in Rotorua, and for different uses of this resource, such as therapeutic hot bathing pools in Tauranga and Rotorua, and industrial applications in Kawerau. The region encompasses high temperature systems at Rotorua and Kawerau (>150°C), and low temperature systems (<150°C) at Tauranga and Awakeri, and near ambient temperature groundwater resources across the region. This is the first RETA that includes geothermal energy. As requested by EECA, the Reporoa Geothermal Field, located in the Waikato region, is also included in this assessment. The report introduces the reader to the key concepts of geothermal energy use for heat supply and various applicable regulatory regimes, including relating to geothermal greenhouse gas emissions and the Climate Change Response Act 2002 and regulations. Analysis of data from these identifies that significant operational greenhouse gas emission reductions (compared with natural gas providing heat for the same duty) can be achieved using geothermal and ground source heat pump (GSHP) technologies.
