Surprise Valley Project & Geothermal Community Meeting

The CGEC and UC Davis Geology Department are conducting research in Surprise Valley to better characterize what geothermal potential may be available in the area. Modoc County has been of interest to the geothermal industry for quite some time, attracting researchers from a number of geothermal companies, government agencies, and universities.

On August 17th, 2013, UC Davis staff, students and faculty presented their current work in the area, and described how it builds on previous work performed by other universities and government agencies over the past decade. The purpose of this meeting was to assure that the community is informed regarding the current knowledge base regarding geothermal resources in the area,and to provide an opportunity for discussing what geothermal energy may mean for the communities in Modoc County.

Geothermal Community Meeting Presentations

Introduction: What is Geothermal Energy?
Elise Brown, California Geothermal Energy Collaborative

What is known about the geothermal resource in Modoc County?
Dr. Jim McClain, UC Davis Geology Department

UC Davis Research Summary: Sam Hawkes
Sam Hawkes, Master Student, UC Davis Geology

UC Davis Research Summary: Andrew Fowler
Andrew Fowler, PhD Candidate, UC Davis Geology

The Future: Challenges and Opportunities
Elise Brown, California Geothermal Energy Collaborative


California Geothermal Heat Pump Efficiency Study


In an effort to assemble as much relevant data as possible to assist with the integration of geothermal heat pump systems, the CGEC has been working on the following two studies. The first is an evaluation of the efficiency of these systems based on the 16 different climate zones in California, while the other assesses the efficiency of GHPs in the 30 most populous metropolitan areas in the United States.

The goal of this study is to determine the cost-effectiveness of geothermal heat pumps when compared to traditional forms of energy (i.e. electricity and natural gas) used in California.  Individual tests are currently being conducted for each of the 16 climate zones within California to determine the specific requirements.  To help find the specific parameters for each system, weather data from the last few years is being used to synthesize a heating and cooling load profile for each of the climate zones.  Along with the weather profiles, the geologic data (i.e. thermal conductivity and thermal diffusivity) for each of the climate zones is being incorporated into the model to refine the testing parameters.  Each profile will be run through a geothermal heat pump design program (GLDesign) to determine the depth of the borehole needed to accommodate the heating/cooling load for each climate zone.  The product of this study will be an install cost and payback period report as well as (funds permitting) an interactive map for home and business owners to calcuate rough ROIs for geothermal heat pump systems in their respective areas.

This study is being funded by the California Energy Commission through the Public Interest Energy Research (PIER) program.  Completion of this study is expected in April of 2012. Reports and findings will be posted as they become available.

Associated Study Maps:

U.S. Metro-Area Geothermal Heat Pump Efficiency Study

The CGEC is currently studying the potential use of geothermal heat pumps, their effectiveness and payback period (ROI) in 30 U.S. metropolitan areas. To identify the total cost of a geothermal heat pump and the system’s associated payback period, ground heat, weather, and house characteristics data have been gathered and are being modeled against an average house’s consumption in each metropolitan area. Energy loads are currently being simulated using a ground heat exchanger modeling software to determine appropriate borehole depths and borehole fields. The product of this study will be an install cost and payback period report as well as (funds permitting) an interactive map for home and business owners to calcuate rough ROIs for their respective areas.

Metropolitan Areas:

  • New York-Northern New Jersey-Long Island, NY-NJ-PA
  • Los Angeles-Long Beach-Santa Ana, CA
  • Chicago-Naperville-Joliet, IL-IN-WI
  • Dallas-Fort Worth-Arlington, TX
  • Philadelphia-Camden-Wilmington, PA-NJ-DE-MD
  • Houston-Sugar Land-Baytown, TX
  • Miami-Fort Lauderdale-Pompano Beach, FL
  • Atlanta-Sandy Springs-Marietta, GA
  • Washington-Arlington-Alexandria, DC-VA-MD-WV
  • Boston-Cambridge-Quincy, MA-NH
  • Detroit-Warren-Livonia, MI
  • Phoenix-Mesa-Scottsdale, AZ
  • San Francisco-Oakland-Fremont, CA
  • Riverside-San Bernardino-Ontario, CA
  • Seattle-Tacoma-Bellevue, WA
  • Minneapolis-St. Paul-Bloomington, MN-WI
  • San Diego-Carlsbad-San Marcos, CA
  • St. Louis, MO-IL
  • Tampa-St. Petersburg-Clearwater, FL
  • Baltimore-Towson, MD
  • Denver-Aurora, CO
  • Pittsburgh, PA
  • Portland-Vancouver-Beaverton, OR-WA
  • Cincinnati-Middletown, OH-KY-IN
  • Sacramento–Arden-Arcade–Roseville, CA
  • Cleveland-Elyria-Mentor, OH
  • Orlando-Kissimmee, FL
  • San Antonio, TX
  • Kansas City, MO-KS
  • Las Vegas-Paradise, NV


Data Portal

Supporting Data for National Geothermal Heat Pump Assessment:

Thermal Conductivity Data Set (Excel)

USGS Groundwater Well Data (Excel)

Argonne Geochemical Database (Excel)

SMU Subsurface Temperature Data (Excel)

Long Valley Caldera Bibliography

As part of the CGEC’s contract with the California Energy Commission research we sought to make research efforts in the Long Valley Caldera, one of California’s most robust yet undeveloped geothermal resources. By compiling a bibliography of all of geothermal studies that have been done in this caldera over the years, we hope that researchers may better understand the resource and correlate data.

The bibliography will be published by the California Energy Commission in Fall/Winter 2011. For now you can download the draft below.

Long Valley Caldera Bibliography

UC Davis Geology Dept. Study:

In Fall 2010, fifteen undergraduate UC Davis Geology majors and seven, graduate students participated in a seminar entitled the “Geology of Geothermal Resources”. The seminar was initiated to familiarize these students with geothermal energy resources through investigating geologic, hydrologic, geochemical, and geophysical aspects of the Long Valley, California geothermal system.

The students engaged in quarter-length research projects and spent time in Long Valley area collecting field data. Their projects and research findings can be found by clicking here.