Figure 20: SMU Estimated Co-Produced Geothermal Potential
Geopressured resources are known to be located in several areas of the U.S., with the most significant of these located in Texas, Louisiana, and the Gulf of Mexico. See section 3.2. for more information on geopressured resources. The map below shows U.S. geopressured basins.
Figure 21: Geopressured Basins in the United States
Note: On the map above, the major oil-producing basins (of all types) in the U.S. are highlighted. The gray stippling indicates the parts of those basins where geopressured strata have been encountered.
Today, U.S. geothermal resources are being used in more than 30 states from New York to Hawaii. The map below from the Geo-Heat Center of the Oregon Institute of Technology shows areas where geothermal energy is being used for power, greenhouses, commercial building heating, and other purposes.
Figure 22: Location of Geothermal Projects and Resources
And finally, geothermal heat pumps can be used nearly everywhere in the U.S. The map below shows where geothermal heat pumps were installed in 2006. The states in darker green have the higher number of installations. .
Figure 23: Geothermal Heat Pump Installations in 2006
How much electricity can geothermal supply worldwide?
There has not been a significant new analysis of international geothermal potential comparable to either the USGS report or the NREL report discussed above. A 1999 study that used fairly conservative assumptions about the resource base and technology concluded that geothermal resources using existing technology have the potential to support between 35,448 and 72,392 MW of worldwide electrical generation capacity. Using enhanced technology (defined as the technology expected to be available by 2009), the geothermal resources could support between 65,576 and 138,131 MW of electrical generation capacity. Assuming a 90% availability factor, which is well within the range experienced by geothermal power plants, this electric capacity could produce as much as 1,089 billion kWh of electricity annually. The estimates produced for world energy potential by this study did not assess the limits of geothermal resource base, nor the potential for new development with significantly different technologies, such as engineered geothermal systems. (5) See also section 2.4.
An estimate of world geothermal resources made by the Energy and Geoscience Institute for the President's Council of Advisors on Science and Technology stated the following for different geologic regimes. (6)
World Continental Geothermal Resources:
Geologic Regime: Joules (J) bbl oil equivalent
Magmatic Systems 15 × 10 24 J 2,400,000 × 10 9 bbl
Crustal Heat 490 × 10 24 J 79,000,000 × 10 9 bbl
Thermal Aquifers 810 × 10 18 J 130 × 10 9 bbl
Geopressured Basins 2.5 × 10 24 J 410,000 × 10 9 bbl
Total Oil Reserves (for comparison) 5,300 × 10 9 bbl*
* National Academy of Sciences, 1990: includes crude oil, heavy oil, tar sands, and oil shale