The Geysers

The Geysers geothermal field in California, USA is one of the oldest and largest developed geothermal fields in the world with a geothermal energy net generating capacity of about  825 MW of electricity with substantially steam-dominated reservoirs. The Geysers has a long history of production since the first power plant, PG&E Unit 1 in 1960,  and has experienced a decline in geothermal productivity over time based on the historic operation of the facility.  More recent operational strategies have significantly stabilized generation.

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GreenFire Energy is working with Calpine Corporation (owner of the  Geysers Power Company, LLC.), on a project to demonstrate GreenFire’s GreenLoop® design called Steam and 2-Phase in idle wells. The aim is to produce energy while maintaining the long-term sustainability of the geothermal resource. The single well project is intended to prove the commercial and technical feasibility of GreenLoop for renewable power generation and to determine if it can be deployed more broadly at The Geysers. The project is funded by the  California Energy Commission (CEC) through a grant of over $2.7 million under the BRIDGE (Bringing Rapid Innovation Development to Green Energy) program.

GreenFire Energy Inc. has been developing technology to apply its GreenFire’s GreenLoop technology in steam dominated and high enthalpy two-phase reservoirs for several years. In Steam and 2-Phase, a downhole tube-in-tube heat exchanger circulates large volumes of a variety of working fluids. The working fluid returns to the surface hot through an insulated tube and can be flashed to produce power at an existing power plant, used for the direct power production by an integrated Organic Rankine Cycle power-generating system, or used for direct use geothermal heating and cooling. Downhole steam condenses on the surface of the heat exchanger transferring its latent heat of vaporization to the working fluid. The condensed steam produces a flow of geofluid condensate towards the bottom of the well, where it builds up to produce the hydrostatic head required to force the liquid deep back into the reservoir. The effect of the downbore closed-loop heat exchanger is to extract heat, rather than mass (or water), from the resource, thereby preserving mass and pressure in the geothermal resource and ensuring the long-term sustainability of the resource.

The project is in progress and results will be made available in a report to the CEC at project completion.

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