For many of you the next statement may be a surprise: Geothermal energy is used to produce electricity in 24 countries.
Leading the way with the largest geothermal capacity is the United States (2,544 megawatts electric, or “MWe”), followed by the Philippines (1,931 MWe), Mexico (953 MWe), Indonesia (797 MWe) and Italy (791 MWe) ( Bertani, 2005).
When Chevron purchased Unocal it became the leading producer of geothermal energy worldwide with projects in Indonesia and the Philippines.
The U.S. geothermal industry is booming thanks to:
- Increasing energy prices.
- Renewable portfolio standards.
- A production tax credit.
California (2,244 MWe) is the leading producer, followed by Nevada (243 MWe), Utah (26 MWe) and Hawaii (30 MWe) (Bertani, 2005).
Alaska joined the producing states during 2006 with two 0.2 MWe power plants placed online at Chena Hot Springs. The plant uses 30 liters per second of 75-degree C water from shallow wells. Power production is assisted by the availability of gravity fed, 7-degree C cooling water.
And a 13 MWe binary power plant is expected to begin production in the fall of 2007 at Raft River in southeastern Idaho.
Idaho also is a leader in direct use of geothermal energy with the state capital building and several other state and Boise city as well as commercial and residential buildings heated using fluids from several interconnected geothermal systems.
Existing U.S. plants focus on high-grade geothermal systems located in the West.
Interest in non-traditional geothermal development, however, is increasing.
For example, a comprehensive new MIT-led study of the potential for geothermal energy within the United States predicts that mining the huge amounts of stored thermal energy in the earth ’s crust not associated with hydrothermal systems could supply a substantial portion – 100,000 MWe – of U.S. electricity by 2050 with minimal environmental impact (Tester, et al., 2006, available at the Idaho National Laboratory).
There also is renewed interest in geothermal production from other non-traditional sources, such as the over-pressured zones in the Gulf Coast and warm water co-produced with oil and gas.
Southern Methodist University recently hosted a conference on geothermal utilization associated with petroleum development.
Ormat Technologies, a major geothermal company, recently acquired geothermal leases in one of the offshore over-pressured zones of Texas. Ormat and the Rocky Mountain Oilfield Testing Center (RMOTC) recently announced plans to jointly produce geothermal power from co-produced water from the Teapot Dome oilfield.
RMOTC estimates that 300 KWe capacity is available for geothermal development from the 40,000 BWPD of 88-degree C water associated with oil production from the Tensleep Sandstone (Milliken, 2007).
The Energy Policy Act of 2005 modified leasing provisions and royalty rates for both geothermal electrical production and direct use. Pursuant to the legislation the Bureau of Land Management (BLM) and Minerals Management Service (MMS) published final regulations for continued geothermal leasing, operations and royalty collection in the Federal Register (Vol. 72, No. 84 Wednesday, May 2, 2007, BLM p. 24358-24446, MMS p. 24448-24469).
Several Web sites periodically offer updated information related to the geothermal industry and the legislation and regulation affecting geothermal development. That includes:
- The Geothermal Energy Association publishes the “GEA Update” semimonthly and also summaries of existing geothermal projects and projects under development in the United States.
- The Nevada Division of Minerals periodically publishes the “Nevada Geothermal Update” and statistical data on geothermal development in Nevada.
Bertani, Ruggero, 2005, World geothermal generation 2001-2005: State of the art: in R. N. Horne and Ender Okanden, eds., Proceedings of the World Geothermal Congress 2005, Antalya, Turkey, 24-29 April 2005, paper 0008, 19 p.
Milliken, Mark, 2007, Geothermal resources at the Naval Petroleum Reserve-3 (NPR-3), Wyoming, in Proceedings, Thirty-Second Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, California, January 22-24, 2007, SGP-TR-183, p, 444-452
Tester, J. W., B. J. Anderson, A. S. Batchelor, D. B. Blackwell, R. D. DiPippo, E. M. Drake, J. Garnish, B. Livesay, M. C. Moore, K. Nichols, S. Petty, M. N. Toksöz, and R. W. Veatch, Jr., 2006, The future of geothermal energy: Impact of enhanced geothermal systems (EGS) on the United States in the 21st century: Idaho National Laboratory External Report INL/EXT-06-11746, 399 p.