Merredin Small Scale Geothermal
Desalination R&D Project
Demonstrating Low-Cost Renewable Water Production for Regional Australia
Good Water Energy is planning a small-scale geothermal research and development project near Merredin in Western Australia to investigate the potential for low-cost freshwater production using geothermal ground source heat pump technology.
The proposed project is intended solely as a research and development demonstration and is not planned as a commercial water production facility.
The objective of the project is to evaluate whether naturally occurring geothermal heat contained within Western Australian granite formations can be used to provide a low-cost renewable energy source for freshwater production in inland and remote regions of Australia.
Phase 1
Geothermal Desalination Demonstration (2026–2027)
The first phase of the Merredin Small Scale Geothermal Desalination R&D Project is planned for 2026 - 2027.
The project proposes the drilling of a single geothermal well into granite formations to access temperatures of approximately 140°C. The well will utilise a geothermal ground source heat pump system incorporating insulated vacuum tubing and thermal syphoning technology to transfer geothermal heat to the surface.
The geothermal ground source heat pump will be located at, or immediately adjacent to, the geothermal resource and will provide thermal energy for a Multi-Effect Distillation (MED) desalination system.
The purpose of the demonstration is to evaluate the technical and economic feasibility of desalinating naturally occurring inland saline groundwater using geothermal heat rather than conventional fossil-fuel or grid-powered energy sources.
Subject to successful testing, the small scale demonstration system may have the potential to produce up to 400,000 litres of freshwater per day from saline groundwater resources.
Good Water Energy estimates that future commercial-scale systems based on this technology may ultimately achieve freshwater production costs below A$0.20 per kilolitre.
The desired outcome of the project is to demonstrate that geothermal ground source heat pump technology may provide a viable freshwater solution for remote communities, agricultural regions, mining operations and drought-affected inland areas of Australia.
Phase 2
Direct Air Capture Water Production Demonstration (2027 - 2028)
The second phase of the Merredin Small Scale Geothermal R&D Project is planned for 2027–2028. This phase will investigate the use of geothermal ground source heat pump technology to support Direct Air Capture (DAC) water production systems operating from geothermal resources within granite formations at temperatures of approximately 150°C to 160°C.
Unlike conventional desalination systems, DAC water production extracts water directly from atmospheric humidity and therefore does not require saline groundwater feedwater. As a result, DAC water production does not generate saline brine streams that typically require management or disposal in conventional desalination processes.
The project will evaluate whether geothermal ground source heat pump technology can provide a practical and low-cost heat source for atmospheric water production in remote and arid regions. Preliminary engineering assessments indicate that future geothermal DAC systems may have the potential to produce freshwater at costs of approximately A$0.30 per kilolitre.
The objective of this research phase is to demonstrate a pathway for freshwater production in remote Australian locations without reliance on conventional electricity generation infrastructure and without the production of saline desalination waste streams.
Research Objectives
The Merredin Small Scale Geothermal R&D Project has four primary objectives:
- Demonstrate geothermal ground source heat pump technology for renewable water production.
- Evaluate low-cost desalination of inland saline groundwater.
- Assess atmospheric water production using geothermal heat.
- Investigate freshwater solutions suitable for remote communities, agriculture, mining and regional development.
Supporting Sustainable Regional Development
Good Water Energy believes geothermal ground source heat pump technology has the potential to contribute to future water security solutions for inland Australia.
The Merredin project is intended to provide engineering, operational and economic data to assist in evaluating whether geothermal heat can support reliable, low-cost and environmentally responsible freshwater production in remote regions where conventional water supplies are limited.
Note
“All production capacities, temperatures, costs and performance figures described on this page are preliminary engineering estimates only and form part of an ongoing research and development program. Actual performance may vary based on geological, operational and environmental conditions.”
