The California Energy Commission (CEC) has selected and recommended for funding two proposed projects by researchers Kurt Nihei and Jonny Rutqvist. Their projects will support the CEC’s efforts to meet the State of California’s 2030 climate commitment to use renewable energy resources for half of the state’s electricity by 2030.
The state is currently on track to meet the goal of renewable energy resources generating 33% of the state’s electricity by 2020. But the next lap to meet the 2030 target will be more challenging. Innovative technologies that can move to commercial application quickly will assure progress. Kurt’s and Jonny’s projects will focus on tackling key technological challenges for geothermal energy, leveraging Berkeley Lab’s expertise in this area.
Kurt Nihei will lead the team working on the project, High-Resolution Micro-earthquake Imaging of Flow Paths Using a Dense Seismic Network and Fast-Turnaround, Automated Processing ($1,672,639). The ability to spatially visualize the transport of water and steam during production and injection is critical to cost-effective operation of geothermal resources. Currently no method exists for imaging the movement of water and steam in a fractured geothermal environment, which poses risk for both energy production and injection of water back into the geothermal reservoir. With the recent development of low-cost, portable seismic recorders, the team plans to assemble a dense network of seismic stations and use automated processing to feed data at high speed to a micro-earthquake imaging system. This system will perform fast, high resolution imaging of fluid and steam moving through the geothermal system. To evaluate the performance and value of this technology, they will conduct a field demonstration at The Geysers, in partnership with Calpine Corporation. EESA scientists participating are: Donald Vasco, Seiji Nakagawa, Katie Freeman, William Foxall, Yves Guglielmi, Michelle Robertson, Craig Ulrich, Todd Wood, John Peterson, and Pierre Jeanne. Other partners in this endeavor: Roland Gritto, Array Information Technology; Steve Jarpe and Larry Hutchings, Jarpe Data Solutions, and Ramsey Haught, consulting geophysicist.
Jonny Rutqvist and his team will work on the project, Coupled Reservoir-Wellborn Thermal-Hydrological-Mechanical-Chemical Modeling ($999,032). This project will address the challenge of providing energy to Californians when energy production from solar and wind renewable energy resources cannot provide power (e.g., night time, or when wind stops or wind turbines must shut down). Geothermal energy has the potential to provide power generation within minutes to cover the gaps, providing greater energy reliability, reducing greenhouse gases from natural gas power plants, and decreasing demand for more expensive storage systems. But flexible-mode geothermal energy production with daily fluctuations will cause extraordinary stress on wellbores and reservoir system. This project focuses on addressing the potential and uncertainty for geothermal energy to provide both base-load and flexible-mode production. The LBNL team will use Thermal-Hydrological-Mechanical-Chemical models to quantify wellbore and reservoir integrity. Modeling the flow processes within well bores can help to identify and address scaling and corrosion issues, and evaluate the mechanical effects of changing pressure and temperature on the well, its casing and the surrounding rock. Defining optimal operating conditions can help significantly in preventing serious corrosion problems. LBNL’s T2Well reservoir-wellborn simulator with the FLAC3D geomechanical simulator will be used to investigate both wellbore integrity and geothermal reservoir behavior. Flexible-mode operations will affect injection and production on the wellbores and reservoir, so the team will model temperature and pressure behavior as well. Calpine will provide pilot flexible-mode operation data to validate the modeling. The goal for the project is to plan to engage the geothermal energy market in deploying the project results. This team includes EESA scientists Quanlin Zhou, Nicolas Spycher, Lehua Pan and Patrick Dobson.
These projects are to be funded from the CEC’s solicitation, Improving Performance and Cost Effectiveness of Small Hydro, Geothermal and Wind Energy Technologies (GFO-16-301). Confirmation is scheduled for December 2016.