Challenge: How to Increase Geothermal Power in California Through Closed-Loop Geothermal Development
The California Energy Commission’s Geothermal Grant and Loan Program funded the project to investigate closed-loop technology to unlock vast geothermal regions of California that cannot be accessed by conventional hydrothermal systems.
Solution: GreenFire Energy’s Closed-Loop Technology
Field scale closed-loop demonstration objectives
• Use an underperforming hydrothermal well at the Coso geothermal field, Coso, CA, USA.
• Design, build, and operate a closed-loop technology demonstration plant.
• Collect enough data to guide development of commercial closed-loop projects.
Field scale closed-loop technology demonstration overview
- Use water as the heat transport and working fluid
- Demonstrate the Downbore Heat Exchanger (DBHX) under various operating conditions
- Verify the accuracy of the well flow, closed-loop flow, and enthalpy testing
- Perform well flow modeling before the DBHX is installed
- Use supercritical CO2 as the heat transport and working fluid
- Demonstrate sCO2 circulated through a 1,083 feet-long tube-in-tube DBHX at four flow rates (including zero flow), combined with five flow settings
- Perform process modeling of the surface equipment and closed-loop modeling
- Demonstrate the field scale application of closed-loop geothermal development
- Demonstrate DBHX in a variety of well configurations depending on heat and rock characteristics
- Perform hot, dry rock modeling to determine power potential of closed-loop technology and the Coso geothermal power potential
Results
GreenFire Energy successfully demonstrated that its closed-loop technology can produce more power and rehabilitate inactive geothermal wells.
- Validated proprietary thermodynamic models to predict performance with either sCO2 or water as heat transport and working fluids
- Validated proprietary thermodynamic models to predict closed-loop power generation
- Validated GreenFire Energy’s closed-loop technology to rehabilitate an inactive well to produce energy.
- The Coso geothermal field has a producing capacity of 140 MW. Analysis shows that with intensive closed-loop development, production could be roughly 10 times greater, or between 1 and 2 GWe.
- The energy from the experiment was estimated in 1.2 MW using existing surface turbine or 1.9 MW by installing a new coupled organic Rankine Cycle (ORC).
Read about the field scale closed-loop demonstration project in the Research Papers:
California Energy Commission, Consultant Report: Closed-Loop Geothermal Demonstration Project, June 2020.
GreenFire Energy Closed-Loop Geothermal Demonstration using Supercritical Carbon Dioxide as Working Fluid, February 10-12, 2020
GreenFire Energy Closed-Loop Geothermal Demonstration at the Coso Geothermal Field, September 2019.