EPIBuilding a Sustainable Future
Lester R. Brown

Chapter 12. Turning to Renewable Energy: Energy from the Earth

It is widely known within the energy community that there is enough solar energy reaching the earth each hour to power the world economy for one year, but few people know that the heat in the upper six miles of the earth’s crust contains 50,000 times as much energy as found in all the world’s oil and gas reserves combined. Despite this abundance, only 9,300 megawatts of geothermal generating capacity have been harnessed worldwide. 63

Partly because of the dominance of the oil, gas, and coal industries, which have been providing cheap fuel by omitting the indirect costs of fossil fuel burning, relatively little has been invested in developing the earth’s geothermal heat resources. Over the last decade, geothermal energy has been growing at scarcely 3 percent a year. Half the world’s generating capacity is concentrated in the United States and the Philippines. Four other countries— Mexico, Indonesia, Italy, and Japan—account for most of the remainder. Altogether some 24 countries now convert geothermal energy into electricity. The Philippines, with geothermally generated power supplying 25 percent of its electricity, and El Salvador, at 22 percent, are the leaders. 64

Beyond this, an estimated 100,000 thermal megawatts of geothermal energy, roughly 10 times the amount converted to electricity, is used directly—without conversion into electricity—to heat homes and greenhouses and as process heat in industry. This includes, for example, the energy used in hot baths in Japan and to heat homes in Iceland and greenhouses in Russia. 65

An interdisciplinary team of 13 scientists and engineers assembled by the Massachusetts Institute of Technology (MIT) in 2006 assessed U.S. geothermal electrical-generating potential. Drawing on the latest technologies, including those used by oil and gas companies in drilling and in enhanced oil recovery, the team estimated that enhanced geothermal systems could be used to develop 100,000 megawatts of electrical generating capacity in the United States by 2050, a capacity equal to 250 coal-fired power plants. To fully realize this potential, the MIT team estimated that the government would have to invest up to $1 billion in geothermal research and development in the years immediately ahead, roughly the cost of one large coal-fired power plant. 66

Even without this research commitment, some 61 U.S. geo­thermal projects were under construction or in development in early 2007. If the United States can develop 100,000 megawatts of geothermal generating capacity, how much could other countries, many of them far more richly endowed, develop with the same technologies? A decade-old estimate for Japan indicated that country could develop 69,000 megawatts of generating capacity. With enhanced geothermal systems, this might easily double to 140,000 megawatts. 67

Indonesia , with 500 volcanoes, 128 of which are still active, undoubtedly has a far greater potential. It could get all its electricity from cheap, easily tapped geothermal energy. With its oil production falling, Indonesia is fortunate to be so richly endowed with an energy source that can last forever. 68

The potential of geothermal energy to provide electricity, to heat homes, and to supply process heat for industry is vast. Among the countries rich in geothermal energy are those bordering the Pacific in the so-called ring of fire, including Chile, Peru, Colombia, Mexico, the United States, Canada, Russia, China, Japan, the Philippines, Indonesia, and Australia. Other geothermally rich countries include those along the Great Rift Valley of Africa, such as Kenya and Ethiopia, and those around the Eastern Mediterranean. 69

In the direct use of geothermal heat, Iceland and France are among the leaders. Iceland’s use of geothermal energy to heat almost 90 percent of its houses has largely eliminated the use of coal for home heating. Geothermal energy accounts for more than one third of Iceland’s total energy use. Following the two oil price hikes in the 1970s, some 70 geothermal heating facilities were constructed in France, providing both heat and hot water for an estimated 200,000 residences. In the United States, individual homes are supplied directly with geothermal heat in Reno, Nevada, and in Klamath Falls, Oregon. Other countries that have extensive geothermally based district-heating systems include China, Japan, and Turkey. 70

Geothermal heat is ideal for greenhouses in northern countries. Russia, Hungary, Iceland, and the United States are among the many countries that use it to produce fresh vegetables in the winter. With rising oil prices boosting fresh produce transport costs, this practice will likely become far more common in the years ahead. 71

Among the 16 countries using geothermal energy for aquaculture are China, Israel, and the United States. In California, for example, 15 fish farms annually produce some 10 million pounds (4.5 million kilograms) of tilapia, striped bass, and catfish using warm water from underground. 72

The number of countries turning to geothermal energy for both electricity and heat is rising fast. So, too, is the range of uses. Romania, for instance, uses geothermal energy for district heating, for greenhouses, and to supply hot water for homes and factories. 73

Hot underground water is widely used for both bathing and swimming. Japan has 2,800 spas, 5,500 public bathhouses, and 15,600 hotels and inns that use geothermal hot water. Iceland uses geothermal energy to heat some 100 public swimming pools, most of them year-round open-air pools. Hungary heats 1,200 swimming pools with geothermal energy. 74

If the four most populous countries located on the Pacific “ring of fire”—the United States, Japan, China, and Indonesia, with nearly 2 billion people—were to seriously invest in developing their geothermal resources, they could easily make geo­thermal energy one of the world’s leading sources of electricity. With a potential in the United States and Japan alone of 240,000 megawatts of geothermal power generation, it is easy to envisage a world with 200,000 megawatts of geothermally generated electricity by 2020. 75

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63. Karl Gawell et al., International Geothermal Development Directory and Resource Guide (Washington, DC: GEA, 2003); REN21, op. cit. note 2, p. 17.

64. Geothermal growth rate calculated using Eric Martinot, Tsinghua-BP Clean Energy Research and Education Center, e-mail to Joseph Florence, Earth Policy Institute, 12 April 2007, and REN21, op. cit. note 44; Philippines geothermal electricity from “World Geothermal Power Up 50%, New US Boom Possible,” press release (Washington, DC: GEA, 11 April 2002); total number of countries with geothermal power from Karl Gawell et al., 2007 Interim Report: Update on World Geothermal Development (Washington, DC: GEA, 1 May 2007), p. 1; El Salvador geothermal electricity from Ruggero Bertani, “World Geothermal Generation 2001–2005: State of the Art,” Proceeding of the World Geothermal Congress (Antalya, Turkey: 24–29 April 2005), p. 3.

65. Jefferson Tester et al., The Future of Geothermal Energy: Impact of Enhanced Geothermal Systems (EGS) on the United States in the 21st Century (Cambridge, MA: Massachusetts Institute of Technology, 2006); John W. Lund and Derek H. Freeston, “World-Wide Direct Uses of Geothermal Energy 2000,” Geothermics, vol. 30 (2001), pp. 34, 46, 51, 53.

66. Tester et al., op. cit. note 65.

67. U.S. projects from Gawell et al., op. cit. note 64, p. 11; Japan from Hal Kane, “Geothermal Power Gains,” in Lester R. Brown et al., Vital Signs 1993 (New York: W. W. Norton & Company, 1993), p. 54; DOE, EIA, “Japan,” EIA Country Analysis Brief (Washington, DC: updated August 2004).

68. Peter Janssen, “The Too Slow Flow: Why Indonesia Could Get All Its Power From Volcanoes—But Doesn’t,” Newsweek, 20 September 2004.

69. World Bank, “Geothermal Energy,” prepared under the PB Power and World Bank partnership program, www.worldbank.org, viewed 23 January 2003.

70. Iceland National Energy Authority and Ministries of Industry and Commerce, Geothermal Development and Research in Iceland (Reykjavik, Iceland: April 2006), p. 16; World Bank, op. cit. note 69.

71. Lund and Freeston, op. cit. note 65, pp. 34, 51, 53.

72. World Bank, op. cit. note 69.

73. Ibid.

74. Lund and Freeston, op. cit. note 65, pp. 46, 53.

75. U.N. Population Division, op. cit. note 23.


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