Clean Energy Australasia (CEA) plans to generate base-load 24/7 electricity with Geothermal Energy optionally augmented by peak load Solar Energy.
Geothermal Energy Sources
Geothermal energy in Australia can be sourced from two principal plays, namely Hot Rocks - Granites and Hydrothermal - Hot Sedimentary Aquifers shown in the diagrams below.
Hot Rocks - Granites Hydrothermal - Hot Sedimentary Aquifers
Hot Rocks - Granites Characteristics Hydrothermal (Hot Sedimentary Aquifers)
- Fractured reservoir - Sandstone reservoir
- Heat generating & convective - Convective heat
- 3-4+km depth - 1-3km depth
- 150 – 250C - 75-150C
Organic Rankine Cycle (Binary Cycle)
The prime surface technology for converting geothermal heat to transmittable electrical energy is the Organic Rankine Cycle (ORC). An ORC plant has the capability of extracting useful work energy from low temperature hot water (>75 degrees C). To achieve this a secondary (binary) fluid that has a lower boiling point than water is used to drive the turbine generator. ORC power plant schematic is shown below.
Geothermal power can be optionally enhanced during daytime by solar power, using Solar Thermal or Solar PV.
Hybrid power plant schematic using Solar Thermal is shown below.
- Geothermal energy provides base-load 24/7 electricity supply
- Solar thermal to enhance peak-load generation during daylight hours
- Powered by natural renewable energy from the Earth and Sun