Updated by Leslie Blodgett GEA 2014
In the 1920s, geothermal electrical generation in the U. S. began at what would become known the world over as The Geysers geothermal field. The U.S. geothermal industry produces more energy from geothermal plants than any other country. Technology experts are expanding the definition of useable geothermal resources and are improving the economics of generation. Geothermal energy produced about 3% of renewable energy-based electricity consumption in the U.S. as of a 2011 DOE count.
Located in the Mayacamas Mountains of northern California, The Geysers is the oldest geothermal field in the U.S. and is the largest commercially productive geothermal field in the world.
U.S. Department of Energy “Renewable Energy Consumption”
2.1. How much geothermal energy is used in the U.S.?
GEA provides estimates on industry statistics that are based on direct feedback from companies. According to GEA research, “The geothermal power industry reached about 3,442 MW at the end of 2013 . . . In 2013 there were about 1,000 MW of planned capacity additions under development and about 3,100 MW of geothermal resources under development.” The industry’s U.S.-based additions in 2013 added about 85 MW of new capacity at new and refurbished power plants in Utah, Nevada, California, and New Mexico.
In the Western states, natural geothermal reservoirs form relatively close to the surface. Surface manifestations such as geysers, hot springs, and even volcanoes give geologists plenty to study to learn what is happening under the surface in states such as California and Nevada. The industry sometimes refers to these Western resources as the low-hanging fruit of the industry, yet when comparing the U.S. Geological Survey (USGS) estimate to current MW under production, only about 10% of the estimated Western states resource base has been developed.
Renewable energy generation in California has been dominated by geothermal energy for since the 1980s (Figure 11). In 2011 the California Energy Commission (CEC) reported 42% of California's commercial in-state renewable electricity generation, or about 6.2% of all power generated in-state, was geothermal.
GEA “Annual” 2014, page 4
Figure 11: California Renewable Energy Generation by Fuel Type, 1983-2010
2.2. What non-conventional technologies are used for geothermal production?
Additional non-conventional technologies being developed and used today. See also section 3.
2.2.1. Working Fluids
Advances in working fluids for binary power systems make it possible to achieve greater heat transfer efficiency while producing power at lower temperatures. The Kalina Cycle’s ammonia-water mix increases production by up to 50% and has been used in applications since the 1990s. ElectraTherm developed the Green Machine, and Turbine Air Systems provided the unit at Beowawe Flash Plant, Nevada.
2.2.2. Distributed Generation
Distributed generation facilities produce geothermal on a smaller scale to provide local or on-site electricity needs of a facility. Energy not being used by the facility can sometimes be sold to the grid. Distributed generation benefits remotely located systems such as Wendel-Amedee in northeastern California; Chena Hot Springs in Alaska; the Oregon Institute of Technology in Klamath Falls; and the Rocky Mountain Oil and Gas Testing Center in Wyoming.
2.2.3. Combined Heat and Power
Combined heat and power plants, also used in fossil fuel technologies, efficiently use low-temperature resources in combination with binary or Organic Rankine Cycle power units. The use of energy is cascaded, which in turn improves the economics of the entire system.
Oregon Institute of Technology “Combined”
2.3. How much geothermal energy is used internationally?
GEA estimates that the international geothermal power market is growing at a sustained rate of 4% to 5% (Figure 12). Almost 700 geothermal projects are under development in 76 countries. “Many countries anticipating the threats caused from by climate change realize the values of geothermal power as a baseload and sometimes flexible source of renewable energy. These countries are on every continent and range from small island nations to large developed economies like China or the United States.”
GEA “Annual” 2014, page 4
Countries around the world also utilize geothermal direct use applications. Including GHPs, direct use capacity reached 51 GWt in 2010. ,
Opportunities for U.S. geothermal companies abound in the global market. In the near term, “exports from the United States are likely to increase in the subsectors that currently enjoy a competitive advantage, including the drilling, financing, and engineering sectors, as well as the growing geothermal heat pump industry,” with estimated U.S. exports totaling $70.1 million worth of geothermal equipment in 2009.
Known potential estimates of geothermal resources in the East African Rift System range between 10,000 and 20,000 MW and remain largely undeveloped. The African Rift Geothermal Energy Development Facility underwrites drilling risks in six African nations and is backed by the United Nations Environment Programme (UNEP).
Kenya and Ethiopia both have installed geothermal capacity already, and both have plans for projects that will be greater than 100 MW. The average geothermal power plant in the U.S. is about 25 MW.
Many countries in Central and South America have developed a portion of their geothermal resources for utility scale power production. El Salvador and Costa Rica are seasoned users of geothermal energy. Chile, Argentina, Columbia, and Honduras have significant amounts of geothermal potential; however, these countries are still in the early stages of exploring and identifying their resources.
Countries within Asia’s geothermal sector including Indonesia, the Philippines, and Japan are incentivizing the development of geothermal resources. Indonesia alone contains over 27,500 MW of potential geothermal resources, the largest known in the world.
In early 2014, GEA estimated Europe and Turkey had a total installed capacity of 1,996 MW for geothermal energy, and there were 111 new power plants under construction or under investigation in EU member states. Within Europe, Italy was the market leader with over 50% of the European capacity. Iceland derived between one-quarter and one-third of its electricity, and 90% of its heating, from geothermal resources; Iceland’s geothermal history is considered a model for transitioning indigenous practices to modern technology use. World Bank and the geothermal initiatives of the European Bank for Reconstruction and Development are supported by European Union climate policies.
1 GWt is the thermal power produced or consumed at the rate of 1 gigawatt. In the electric power industry, thermal power (as in MWt or GWt) refers to amount of heat generated, which creates steam to drive a turbine. Electric power (as in MWe or GWe) is the amount of electricity generated.
National Export Initiative, pp. 18-19
GEA “Annual” 2014, page 8
GEA “International” 2010, page 5
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