The Earth houses a vast energy supply in the form of geothermal resources. Domestic resources are equivalent to a 30,000-year energy supply at our current rate for the United States! In fact, geothermal energy is used in all 50 U.S. states today. But geothermal energy has not reached its full potential as a clean, secure energy alternative because of issues with resources, technology, historically low natural gas prices, and public policies. These issues affect the economic competitiveness of geothermal energy.
Issues surrounding the adoption are divided into five main categories:
Geothermal resources are categorized in several layers of accessibility and feasibility, from broadest criteria (i.e., total physically available), to criteria that includes technical and economic considerations. The total resource base is scaled downward to accessible resource, and finally to a category called developable resource.
The table below shows estimates for the different geothermal resource categories, as compiled by the workshop experts. These estimates show the enormous potential of the U. S. geothermal energy resource. New low-temperature electric generation technology may greatly expand the geothermal resources that can be developed economically today.
Estimated Developable Resource* |
|||||
Estimated Accessible Resource (MWe) |
2006 (Actual MWe) |
2015 (MWe) |
2025 (MWe) |
2050 (MWe) |
|
Shallow Hydrothermal(Identified) >90˚C/194˚F |
30,000 |
2,800 |
10,000 |
20,000 |
30,000 |
Shallow Hydrothermal(Unidentified) >150˚C/302˚F |
120,000 |
TBD |
TBD |
TBD |
|
Co-Produced & Geopressured |
>100,000 |
23 |
10,000 to 15,000 |
70,000 |
>100,000 |
Deep Geothermal |
1,300,000 to 13,000,000 |
0 |
1000 |
10,000 |
130,000 |
Thermal Uses |
(MWt) |
(MWt) |
(MWt) |
(MWt) |
|
Direct Uses |
>60,000 |
620 |
1600 |
4,200 |
45,000 |
Geothermal Heat Pumps |
>1,000,000 |
7,385 |
18,400 |
66,400 |
>1,000,000 |
GHP Avoided Power |
120,000 |
880 |
2,100 |
8,000 |
120,000 |
*These resource estimates represent a consensus of a group of experts who considered existing resource assessments (referenced on next page). There is considerable uncertainty in the estimates as many resources are hidden and exploration to date has been relatively limited. The figures shown above are not a resource assessment, but, even with uncertainty, clearly show that the U.S. geothermal resource is a very large and important domestic energy source.