Investigating Flexible Generation Capabilities at the Geysers
Geysers geothermal flexibility enabling grid integration of other renewable resources
Geysers Power Company, LLC
Recipient
Middletown, CA
Recipient Location
2nd
Senate District
4th
Assembly District
$2,822,000
Amount Spent
Completed
Project Status
Project Result
The project conducted a study to investigate flexible electrical generation capabilities at The Geysers. The modeling work performed in this project resulted in successful development and application of a simulation-optimization framework for the optimal control of the steam field under load curtailment. Upgrades installed during this study removed turbine related constraints, made it feasible to achieve rapid cutbacks using existing ramp rates, and provided an incremental increase in existing flexible generation capabilities. Field-testing and modeling results show that steam well and pipeline corrosion is a major constraint on steam-field operations. However, results from this study will guide economic evaluations and future capital improvements needed to expand the flexible generation capabilities at The Geysers.
The Issue
Electric system operators need solutions to effectively manage large quantities of intermittent energy sources and maintain grid reliability. While geothermal energy has served to provide mainly a steady level of baseload energy, reducing impacts of intermittent energy will require quickly dispatchable sources of generation with the flexibility to ramp up or down as needed. Modifying geothermal operations to provide more flexibility would be valuable to system operation but requires overcoming physical and operational issues.
Project Innovation
This project seeks to expand flexible generation capabilities of The Geysers geothermal facilities and support electrical grid reliability. The current operational configuration of The Geysers were thoroughly evaluated through modeling and field testing to determine ways to expand flexible generation capabilities. Steam field and power plant equipment were modified and tested in various load cycling scenarios to determine operating capabilities and limitations of equipment to achieve flexible generation while avoiding or minimizing any potential damage to facilities. The project team concluded that individual Geysers power plants can operate in a flexible or cyclic operating mode down to their existing minimum generating operating limits. However, when multiple power plants are in cyclic operating mode at the same time, operators were challenged by the required monitoring and related manual adjustments.
Project Benefits
The technical and economic benefits of this study will come from expanding the flexible generation capabilities of The Geysers generation facilities to maintain grid reliability and help support additional variable renewables to meet the state's RPS goals.
Affordability
Geothermal power plants support resource adequacy and RPS goals, voltage support, and scheduled reactive power. This study has shown that Geysers geothermal resources have the potential to contribute significant flexible capacity to the California electrical grid.
Reliability
The primary benefit to ratepayers from this project is to help sustain ongoing safe reliable operation of the Geysers geothermal field while adding some incremental amounts of flexible capacity and avoid any significant damage to its facilities. This project studied the existing capabilities and limits to provide flexible capacity in terms of frequency, magnitude, duration and power plant ramp rate.
Key Project Members
Samuel Mason
Subrecipients
Multiple Parties
Multiple Equipment Suppliers
Multiple Mechanical Subcontractors
Multiple Electrical Subcontractors
Match Partners
Geysers Power Company, LLC
Multiple Equipment Suppliers
Multiple Mechanical Subcontractors
Reservoir Engineering Contractor
