AZGS | Menu
Geothermal potential across the U.S.

State Geological Surveys:
Tapping Geothermal Energy in the 21st Century

America’s state geological surveys, under the auspices of the Association of American State Geologists (AASG), are taking a leading role in exploring America’s geothermal potential in the 21st century.   AASG and its partners are striving to broaden US energy landscape with environmentally sound, renewable geothermal energy.

To support AASG efforts, the Department of Energy (DOE) is providing a three year, 18-million dollar grant as part of the American Recovery and Reinvestment Act (ARRA) .  Eighty-five percent of the funds are slated for the 46 participating states for compiling, digitizing, and documenting data for populating the National Geothermal Data System (NGDS). 

In support of NGDS - a national, distributed, and interoperable geothermal data system - state geological surveys are building four regional data / training centers (Arizona Geological Survey, Kentucky Geological Survey, Illinois State Geological Survey and Nevada Bureau of Mines and Geology) and 46 states are delivering geothermal data.  

NGDS will serve data to government, NGOs and industry to reshape America’s energy by tapping into renewable geothermal energy for homes, industry and communities.  Data delivery will be complemented by a suite of free desktop tools for mining, sharing and evaluating data.

Heat pump (loop) technology diagram.

Geothermal energy abounds in the US, ranging from low-temperature, ground-source heat that can be extracted to cool homes in the summer and heat them in the winter; to direct use of low- to moderate-temperature water (68 F to 302 F) for homes, industry and commercial uses; to high-temperature systems capable of driving turbines and generating electricity. 

US  geothermal resources are capable of providing a substantial portion of the nation’s energy needs in the 21st century.  

Principal Means of Geothermal Energy Production

  • Heat Pump (loop) Technology – highly efficient ground source approach with nationwide potential.
  • Direct Use Geothermal – Using moderate temperature waters for direct heating, highest potential is in western US, Alaska and Hawaii.
  • Geopressured – Deeply buried, overpressured reservoirs of hot brine largely limited to the Gulf of Mexico and environs.
  • Enhanced Geothermal Systems – deep engineered reservoirs requiring the addition of water, potentially nationwide at depths of 6- to 8-km.
  • Hydrothermal  - Higher temperature sources used to pilot dry steam, flash steam, or binary cycle geothermal power plants principally in the western US, Alaska and Hawaii.


AASG Populating National Geothermal Data System with State Data  

Geothermal well in Clifton, Arizona.

Each state brings a broad and diverse suite of data needed for effective exploration and development of geothermal energy to the table.  These data are, however, largely in analog form and must be digitized and tagged with metadata before submittal to NGDS.  Bulleted below is an abridged summary of aggregate data for the fifty states that will be available through the NGDS:

  • Well data – aggregate of 2 million water, oil & gas, and geothermal wells
  • Hot springs water chemistry – for more than 6,600 sites
  • Bottomhole temperatures – from more than 750,000 wells
  • Well cores and cuttings – information on over 17 million ft from more than 540,000 wells
  • Existing digital data bases – over 6 terabytes of data ready now
  • Digital geologic maps – an aggregate of nearly 100,000 maps
  • Direct  use geothermal data 
  • Geo-pressured data – 44,000 well logs and experimental results from the Gulf Coast
  • Online publications – more than 3,500 publications in place with an additional 70,000+  anticipated
  • New map data -- collecting geothermal temperatures and gradients for states where information is lacking

Funding by The Department of Energy (DOE) Geothermal Technologies Program





Collaborative Partners Include

Related News Releases

(5.5.2010) Press Release: State Geological Surveys Kick Off $18 Million Dollar Geothermal Program

(10.30.2009) Press Release: DOE Awards Arizona Led Coalition $17.8 Million Dollars for National Geothermal Effort

Related Links

Geothermal Resources Council

Geothermal Energy Association

Association of American State Geologists 

National Geothermal Data System  

Northern Arizona University     

US Geological Survey    

DOE Geothermal Technologies Program 

Renewable Resource Data Center  

SMU Geothermal Laboratory      

OIT Geo-Heat Center  



Need Help Using RSS-Feeds? This website is best viewed with Firefox | For website feedback:
Copyright © The Arizona Geological Survey, 2009. All rights reserved.