In common parlance, a myth is a fiction -- something which is untrue. An invented truth takes on the proportion of being a myth when it is repeated often enough to take on a life of its own, to appear to have meaning in its own right.

Today, geothermal developers face many obstacles, and one of them is inadequate public understanding of geology, hydrology, and the related sciences that underlie geothermal energy. A recent publication for the National Geothermal Collaborative (NGC) found that widespread misconceptions about geothermal energy posed major barriers to its use. The following highlight some of the most prevalent myths about geothermal energy. Click on the link below to reveal the truth behind the myth:

Myth: Geothermal Energy is Experimental and Not Yet Widely Used

Myth: Geothermal Resources are Nonrenewable

Myth: Geothermal Power Plants Emit Smoke

Myth: Extraction and Injection of Geothermal Brines Contaminates Drinking Water

Myth: Natural Geothermal Surface Features Are Used During Geothermal Development

Myth: Current Geothermal Development Alters Geothermal Land Features



Myth: Geothermal Energy is Experimental and Not Yet Widely Used
Truth: Geothermal resources have been in use in the United States for more than 10,000 years, according to archaeological evidence.
The Paleo-Indians first used geothermal hot springs for warmth, cleansing, and minerals through direct use. The first large-scale geothermal electricity-generating plant opened at Larderello, Italy in 1904, and continues to operate successfully. The first commercial U.S. geothermal power plant producing power to the utility grid opened at The Geysers in California in 1960, producing 11 megawatts of net power. The Geysers system continues to operate successfully today, and represents the largest single sources of renewable energy in the world. The United States has nearly 2800 megawatts of electricity connected to the grid. As the world’s largest producer of geothermal energy, The U.S. generates a yearly average of 15 billion kilowatt hours of power, comparable to burning about 25 million barrels of oil or 6 million short tons of coal per year. Geothermal energy is used for electrical power production in 21 countries, and supplies significant amounts of electricity to countries such as the Philippines, where 27 percent of electricity derives from geothermal sources. Even so, this worldwide use represents only a fraction of the potential power that could be generated from geothermal resources. As technology continues to advance, the expected cost and risk of using geothermal resources will continue to decline while the geothermal contribution to our energy needs will continue to expand. Back to top

Myth: Geothermal Resources are Nonrenewable
Truth: Geothermal resources are, by both legal classification and scientific definition, renewable.
The word “geothermal” comes from the Latin roots, “geo,” defined as “Earth,” and “thermal,” defined as “heat.” Geothermal energy is literally heat from the Earth, and the Earth’s heat is essentially limitless. As far as today's science can determine, the center of the Earth has been very, very hot for some 3.9 billion years and will continue to be hot for at least that far into the future. At the Earth’s core, 4,000 miles deep, temperatures can reach upwards of 9,000 0 F (5,000 0 C). In addition, the underground water or steam used to convert heat energy into power will never diminish if managed properly, because precipitation will continue to recharge geothermal reservoirs. Geothermal resources can be considered renewable “on timescales of technological/societal systems and do not need geological times for regeneration as fossil fuel reserves do.” The National Energy Policy Act of 1992 and the Pacific Northwest Electric Power Planning and Conservation Act of 1980 both define geothermal energy as a renewable resource. The Larderello field in Italy, site of the world’s first geothermal power plant, is currently celebrating its 100th anniversary of commercial electricity production. Back to top

Myth: Geothermal Power Plants Emit Smoke
Truth: the visible plumes seen rising from water cooled geothermal power plants are actually water vapor emissions (steam), not smoke, and are caused by the evaporative cooling system.
No combustion of fuels occurs to produce electricity at a geothermal facility. Air cooled systems emit no water vapor, and thus blend easily into the environment. In a water cooling process, fifty percent or more of the geothermal fluid that enters the cooling tower is emitted to the atmosphere as water vapor, while the remainder recycles back into the reservoir. Geothermal water vapor emissions contain only trace amounts of the pollutants typically found in much greater quantities in coal and gas power plant emissions. Back to top

Myth: Extraction and Injection of Geothermal Brines Contaminates Drinking Water
Truth: No contamination of groundwater has occurred as a result of geothermal activity.
While groundwater contamination has been a problem in the past or in areas outside the U.S., today every effort is made by the geothermal industry to minimize the affects of geothermal development on local water regime and surface features. Geothermal brines are injected back into geothermal reservoirs using wells with thick casing to prevent cross-contamination of brines with groundwater systems. A well casing is composed of thick specialized pipe surrounded by cement in order to prevent any contamination as the geothermal fluids are put back into the reservoir. Once the brines are returned to the geothermal reservoir, they are re-heated by the Earth’s hot rocks, and can be used over and over again to produce electricity. Besides voluntary mitigation efforts on the part of developers, certain geothermal activities, such as injection, are regulated by the EPA to coincide with the Underground Injection Control Program requirements and the BLM and state well construction requirements. These federal regulations were instituted with the specific intent of protecting groundwater resources. In the U.S., according to federal regulations, only the lower-temperature geothermal waters that are of drinking-water quality and that do not disrupt ecosystems might be allowed to flow into streams or lakes. Most geothermal applications, including all higher-temperature geothermal systems, require that the water be injected back into the reservoir. Back to top

Myth: Natural Geothermal Surface Features Are Used During Geothermal Development
Truth: While surface features such as geysers or fumaroles are typically useful in identifying the locations of geothermal resources, these features are not used during geothermal development.
Instead, drilling that extracts geothermal resources takes place close to these features. In fact, it is impossible to extract geothermal resources, for the purpose of large scale utility development, from geothermal surface features themselves. Further, while almost all geothermal resources currently developed for electricity production are located in the vicinity of natural geothermal surface features, much of the undeveloped geothermal resource base may be found deep under the Earth without any corresponding surface thermal manifestations. Whether or not geothermal fluids will manifest on the surface depends on the natural “plumbing” underground which may or may not connect geothermal resources to the surface of the Earth. At MedicineLake in California, for example, there is only a single, very weak thermal manifestation at the surface, yet extensive geothermal resources have been identified underground. Resources that are more difficult to identify, without surface expression, are less likely to be explored given the limitations of today’s technology. While the size and extent of geothermal surface features can be a rough guide to the size of a geothermal resource, a considerable amount of uncertainty still exists.  Back to top

Myth: Current Geothermal Development Alters Geothermal Land Features
Truth: Although all geothermal development can potentially disrupt land features, proper project management reduces or altogether eliminates land alteration.
U.S. law prohibits geothermal development in sensitive areas as a precautionary measure. Geothermal development is forbidden in and around YellowstoneNational Park, for example, in order to protect the famous geysers in the park. The geothermal development of the 1970s and early 1980s, which sometimes altered surrounding geysers, fumaroles and other surface features, prompted U.S. regulation, including the Steam Act and other national laws, which protect national parks and their significant thermal features from adverse impacts. Geothermal developers make every effort to protect natural surface features, both by strictly adhering to federal laws, and also by employing their own independent management techniques. It is important to note, in addition, that geysers and fumaroles can both arise and disappear naturally, without any human interference. In some developed geothermal fields, it is difficult to distinguish such natural ephemeral behavior from changes induced by geothermal or potable water resource development. Over time, pressure increases in hot springs can cause geysers to erupt continuously and become narrower in shape. If increased pressure causes a geyser to explode, it often resumes its previous shape and pressure as a hot spring. Moreover, the fluid pathways that feed a surface manifestation can be altered due to natural processes such as deposition and dissolution of minerals, interaction with meteoric water, and seismicity. Any of these factors can cause dramatic changes in the location, appearance, or existence of manifestation. At times, weather patterns such as droughts have been shown to affect the activity of geothermal surface features. So both natural phenomenon and geothermal development have the potential to—but do not always—alter geothermal land features. Back to top