A New Geothermal Map of the United States

Imagine a renewable energy resource capable of producing more than 10 times the energy of the installed capacity of coal in the US. That’s the potential for Geothermal Energy in the United States, according to a recently completed 3-year project supported by Google.org to update the Geothermal Map of North America.

The study conducted by SMU Geothermal Laboratory, led by Principal Investigator Dr. David Blackwell, incorporated tens of thousands of new thermal data points to create the most data rich perspective on US geothermal resources to date. The full results can be seen in the updated Google Earth layer on U.S. Geothermal Resources and in SMU’s paper to be presented at the Geothermal Resources Council Annual Meeting.

The project estimates that Technical Potential for the continental US exceeds 2,980,295 megawatts using Enhanced Geothermal Systems (EGS) and other advanced geothermal technologies such as Low Temperature Hydrothermal.

2011 Geothermal Heat Flow Map of the US

The new estimates are compliant with the new global geothermal mapping protocol developed by SMU, Hot Dry Rocks PTY, GeoWatt Ag, and Google.org which is now recognized by the International Energy Agency and the International Geothermal Association. Under the protocol, Technical Potential is limited to depths of 3.5 to 6.5 km (6.5 to 10 km is considered “Theoretical Potential” under the protocol) and inaccessible zones such as national parks and protected lands are eliminated.

How'd they do it?

The SMU team has been developing entirely new pictures of the earth's geothermal resources. They started by aggregating thousands of new Bottom Hole Temperature (BHT) readings from oil, gas, and water wells in previously under-sampled regions of the U.S. For example, The 2004 Geothermal Map of North America used only 5 heat flow points informing geothermal estimates for West Virginia, compared to the additional 1,455 BHT points in the updated version. In addition, the team has improved estimates of heat flow through the earth's crust with better regional lithologic data.

The updated map is a testament to the incredible SMU team: Dr. David Blackwell, Maria Richards, Zachary Frone, Joseph Batir, Ryan Dingwall, Andrés Ruzo, and Mitchell Williams.

We’re excited that with improvements in EGS technology, all of these resources could one day be harnessed to provide clean, reliable, baseload power -- energy that’s available every hour of every day.

Posted by Parag Chokshi, Clean Energy Team, Google.org