- Hydrothermal fluids can be utilised in several different processes to turn the heat into electricity. One of the current, most selected processes uses equipment called Binary Organic Rankine Cycle (ORC) turboexpander generators.
- The ORC uses an organic working fluid (refrigerant or hydrocarbon) in a closed cycle where the geothermal fluid heat is used in an evaporator to vaporise the pressurised fluid so that it enters a turboexpander generator, producing electricity. The resulting lower pressure vapour is cooled in a condenser resulting in a low pressure fluid. This fluid enters a pump that outputs high pressure fluid ready to enter the evaporator again, continuing the closed working cycle.
- The efficiency of this equipment relies on effective heat transfer from the geothermal well fluids, correct selection of the closed system working fluid, and sufficient cooling to provide the largest temperature differential (geothermal fluid compared to working fluid).
- Modular, scalable, proven and available from multiple good suppliers.
