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October 2014 Brief: Volume 21, Number 28

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Geothermal Energy in Iowa Has Significant Potential


by Deborah D. Thornton



More Americans are coming to their senses about the global warming movement. An April 2014 poll by Gallup shows that only 34 percent of Americans are greatly worried about “global warming” or “climate change.”[1] This is down from 41 percent in 2007, the height of the Al Gore Inconvenient Truth scam. We have good reason to be skeptical. For example, the Earth is currently cooling, not warming; warming and cooling cycles have occurred naturally for thousands of years; the computer models don’t work accurately; and CO2 is not a pollutant, it makes the oxygen cycle work. Basically, global warming/cooling is normal and people are not causing the end of the world.


However, energy conservation is something we can all support. Conservation and low energy prices make a significant positive difference in the economy and lifestyle of all people. Government control of our energy decisions does not.


One energy source which can help is geothermal energy. Geothermal energy is created by the natural, internal heat of the earth coming in contact with groundwater. It’s been here for millions of years and will be unending for many millions more.[2] It should be a darling of environmentalists, as the earth’s interior heat temperatures and the energy it can produce are both constant and significant. There is potential for widespread distribution of generation facilities, it is highly base-load dispatchable without storage, there is a small land footprint, and there are low emissions.


Unfortunately, geothermal power density – like that of wind and solar – is low, in the 3 to 10 MWm2 range.[3] This is better than ethanol and wind energy and comparable to solar. More importantly, geothermal energy is highly controllable and storable, meaning it runs at a higher load factor than either wind or solar. It is virtually invisible after installation, as all piping is deep underground, with only control equipment above ground. Geothermal is also an ideal source of base-load energy supply. Solar and wind are not. Therefore it provides a critical backup to these uncontrollable, indeterminate, and temperamental sources. This alone should make geothermal energy popular.


Most commercial geothermal plants are on the “ring of fire” for volcanic and earthquake activity, where the earth’s crust is “thin” and wells are easily managed. Yet new enhanced geothermal systems are making it feasible in previously unconsidered places. A potentially significant field was discovered in eastern West Virginia, a key location for high demand by Atlantic coast residents.




Map of Iowa Geothermal Energy Potential, National Renewable Energy Laboratory, 2009







The United States has the largest geothermal capacity at about 3.4 GWe, representing almost one-third of the worldwide capacity. According to the Geothermal Energy Association (GEA), 124 of 674 new projects are in the United States.[4] The GEA states that worldwide the industry is “booming,” with growth of 4-5 percent per year. Currently there are several very large (100 MW) plants being built in Kenya and Ethiopia, where electricity is desperately needed.[5] In comparison, the average size of a U.S. plant is about 25 MW.


About 85 MW of new capacity was added in the U.S. during 2013 through new or refurbished facilities in California, Nevada, New Mexico, and Utah. There is another 1,000 MW of capacity planned and another 3,100 MW under development.[6] The industry estimates that in California, Nevada, and Utah alone over 50 percent of potential capacity is “untapped.” Other states with recently discovered potential include Arkansas, Iowa, Louisiana, Kansas, Mississippi, Nebraska, New York, North Dakota, Pennsylvania, South Dakota, and Texas.


While most high-temperature geothermal in the U.S. is in the Mountain West, ground temperatures of 40 to 90 degrees Fahrenheit are found not very far underground (10-20 feet) throughout the country, making it, at the very least, suitable for home and business heat pumps and stand-alone supplemental heating. Unfortunately, there are significant difficulties in building new commercial geothermal plants, including policy barriers, permitting delays, leasing conflicts, environmental assessment costs, and transmission issues. Policy gridlock at the federal level, as well as unequal treatment of various energy sectors, are key negative factors.


The 2009 geothermal resource map from the National Renewable Energy Laboratory (NREL) shows a large area of Southeastern Iowa may have significant potential for commercial geothermal energy production with the use of the newest enhanced geothermal technology. This area reaches from Clinton/Davenport in the east-central part of the state, over past Iowa City towards Brooklyn, and down through Mount Pleasant to Lee County and the Missouri border.[7]


This is a significant finding and one which should drive the Legislature and Governor towards policies resulting in quicker development and operation of new facilities in Iowa.


The industry estimates that there are 170 permanent, full-time jobs created per 100 MW of power provided, and about 640 jobs created during the construction process.[8] If the siting and permitting process time in Iowa could be reduced, and even if the facilities were in the 25 MW size, geothermal energy could bring many new jobs and economic development to an important area of our state.


[1] Alan Neuhauser, “Poll: Americans Still Unconcerned About Global Warming,” US News and World Report, April 4, 2014, <> accessed on June 18, 2014.
[2] William Tucker, “Terrestrial Energy (Geothermal, Nuclear vs. Fossil Fuels and Renewables),”, January 16, 2012, <> accessed on June 25, 2014.
[3] Lee Allison, “New Source of Geothermal Energy in Western U.S.,” Arizona Geology, September 29, 2012, <> accessed on July 8, 2014.
[4] Benjamin Matek, “International Geothermal Power Project List as of August 2013,” Geothermal Energy Association, <> accessed on June 15, 2014.
[5] Benjamin Matek, “2014 Annual U.S. & Global Geothermal Power Production Report,” April 2014, p. 8, < Final.pdf> accessed on June 15, 2014.
[6] Ibid., p. 4.
[7] Billy J. Roberts, “Geothermal Resource of the United States,” October 13, 2009, National Renewable Energy Laboratory, <> accessed on July 14, 2014.
[8] “New Industry Paper Examines Reports on Geothermal Power Costs and Benefits,” June 2014, <> accessed on July 13, 2014.


Deborah D. Thornton is a Research Analyst with Public Interest Institute, Mount Pleasant, Iowa. Contact her at


Permission to reprint or copy in whole or part is granted, provided a version of this credit line is used:"Reprinted by permission from INSTITUTE BRIEF, a publication of Public Interest Institute." The views expressed in this publication are those of the author and not necessarily those of Public Interest Institute. They are brought to you in the interest of a better-informed citizenry.




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