USGS Investigations of Geothermal Systems in the Great Basin and Plans for Future Resource Assessment Studies

Geothermal Resources ofCalifornia: Moving fromAssessments towardsDevelopment

Colin F. Williams

USGS, Menlo Park, CA

U.S. Department of the Interior

U.S. Geological Survey

Geothermal Resources ofCalifornia: Moving from Assessmentstowards Development

Sean Hagerty, Bureau of Land ManagementSean Hagerty, Bureau of Land Management

Jim Lovekin, GeothermExJim Lovekin, GeothermEx

Marshall Reed, US Geological SurveyMarshall Reed, US Geological Survey

Idealized Geothermal Power PlantIdealized Geothermal Power Plant

Need: Heat (Temperature) and Fluid (Permeability)Need: Heat (Temperature) and Fluid (Permeability)

GEA 1999GEA 1999

Some Terminology

Geothermal Resources are characterized by the degree ofknowledge (e.g., discovered vs. undiscovered) andeconomic/technological feasibility.Geothermal Resources are characterized by the degree ofknowledge (e.g., discovered vs. undiscovered) andeconomic/technological feasibility.

Resource – The portion of the resource base that can berecovered as useful heat under current and potentialeconomic and technological conditions.Resource – The portion of the resource base that can berecovered as useful heat under current and potentialeconomic and technological conditions.

Reserve - The identified portion of the resource that can berecovered economically using existing technology.Reserve - The identified portion of the resource that can berecovered economically using existing technology.

Status of California Geothermal

At one point approximately 2800 MWe installedAt one point approximately 2800 MWe installed

Currently >2000 MWeCurrently >2000 MWe

1978 USGS Resource Assessment1978 USGS Resource Assessment

12,000 MWe in identified systems12,000 MWe in identified systems

>10,000 MWe in undiscovered systems>10,000 MWe in undiscovered systems

2004 Resource Assessment - Geothermex2004 Resource Assessment - Geothermex

>5000 MWe in identified, conventional resources>5000 MWe in identified, conventional resources

Largest resource in U.S., both installed and inpotential developmentLargest resource in U.S., both installed and inpotential development

Developments in Geothermal

1.Temperature >200oF(95 oC) and Depth >10,000ft (3 km) forpower production1.Temperature >200oF(95 oC) and Depth >10,000ft (3 km) forpower production

2.New systems discovered2.New systems discovered

3.Improved techniques for characterizing reservoirs3.Improved techniques for characterizing reservoirs

4.Increasing use of injection to sustain production4.Increasing use of injection to sustain production

5.Development of Enhanced Geothermal Systems (EGS)technology5.Development of Enhanced Geothermal Systems (EGS)technology

6.Potential for more accurate estimates of undiscoveredresources6.Potential for more accurate estimates of undiscoveredresources

Future Directions

Comprehensive Resource AssessmentsComprehensive Resource Assessments

Combine National, State and Local Information in a SingleCoherent ProductCombine National, State and Local Information in a SingleCoherent Product

Confirmation of ResourceConfirmation of Resource

Refined Land Use PlansRefined Land Use Plans

ExplorationExploration

Continuing Development of EGS TechnologyContinuing Development of EGS Technology

New and Unconventional ApplicationsNew and Unconventional Applications

HydrogenHydrogen

Local Use in Urban AreasLocal Use in Urban Areas