Geothermal Energy
What Is Geothermal Energy? Geothermal energy is the natural heat of the Earth, which is transferred from the hot core of the planet to the much cooler surface by conduction of heat through rocks. It is this same heat that produces the molten lava, hot ash and gases that we see spewing from an erupting volcano. Geothermal energy can be harnessed by modern technology and brought to the surface as steam or hot water and converted to electricity.
Miles beneath the Earth's surface lies one of the world's largest energy resources—geothermal energy. Our ancestors have used geothermal energy for cooking and bathing since prehistoric times. Today, we use this enormous energy reservoir to supply millions of people with clean, low-cost electricity. Geothermal power plants use wells to pipe steam and hot water trapped underground to the surface to make electricity. The power plants produce electricity at 5¢ to 7.5¢ per kilowatt-hour. The Geysers Power Plant in northern California—the world's largest geothermal power plant—generates more than 1700 megawatts of electrical power. Geothermal power plants are highly reliably and can operate 24 hours a day. Most power plants operate more than 95 percent of the time.
A comprehensive new MIT-led study of the potential for geothermal energy within the United States has found that mining the huge amounts of heat that reside as stored thermal energy in the Earth's hard rock crust could supply a substantial portion of the electricity the United States will need in the future, probably at competitive prices and with minimal environmental impact.
An 18-member panel led by MIT prepared the 400-plus page study, titled "The Future of Geothermal Energy" (PDF, 14.1 MB). Sponsored by the U.S. Department of Energy, it is the first study in some 30 years to take a new look at geothermal, an energy resource that has been largely ignored.
The goal of the study was to assess the feasibility, potential environmental impacts and economic viability of using enhanced geothermal system (EGS) technology to greatly increase the fraction of the U.S. geothermal resource that could be recovered commercially.
Although geothermal energy is produced commercially today and the United States is the world's biggest producer, existing U.S. plants have focused on the high-grade geothermal systems primarily located in isolated regions of the west. This new study takes a more ambitious look at this resource and evaluates its potential for much larger-scale deployment...
MIT-led panel backs 'heat mining' as key U.S. energy source
--------------------------------------------------------------------------------
Gene Wescott, a geophysicist and Professor Emeritus at the University of Alaska, Fairbanks has explored the possible use of geothermal energy in the Aleutian Islands to produce hydrogen for use in clean automobiles.
...Several decades ago, when the world was searching for new types of energy, Professor Wescott was dispatched from his campus in Fairbanks to a long string of islands that stretches for 1,100 miles from Alaska into the northern Pacific Ocean. The Aleutians are volcanic islands, many of them quite active today, and they are literally sitting on shallow beds of molten rock, surrounded by water.
The U.S. Department of Energy wanted to know if those desolate islands could be used to produce geothermal energy. The idea was that the hot areas beneath the surface might provide a continuous source of blistering hot water, which could in turn be flashed to steam and used to turn turbines and produce electricity. The precedent had been set in California and Iceland. California draws a small percentage of its electricity from geothermal power plants near San Francisco.
Energy for Centuries
So Wescott traveled out the Aleutians, drilling a few test wells along the way, and he found just what common sense would suggest should be there. The rocks beneath the surface were very, very hot.
.
.
.
But here's the hitch: Why build power plants hundreds, or thousands, of miles away from any users? It isn't practical to run power lines from the Aleutians all the way to the major population centers of the western United States, so what Wescott really found was an enormous source of energy where nobody could use it.
So the whole idea kind of died, except in the mind of Gene Wescott...
In recent years, Wescott has returned to the idea of building geothermal power plants in the Aleutians, and using that electricity to produce hydrogen. The hydrogen could be liquified, he says, and shipped to Asia or the west coast of the United States. One of the largest geothermal resources he found in his earlier research is near the major deepwater port of Dutch Harbor, making it almost seem as though providence planned the whole thing.
Free from Oil
ReplyDeleteListen to Gene Wescott with your imagination set free and you will see ways to light our cities and power our cars without destroying the environment.
Wescott is a geophysicist at the University of Alaska, Fairbanks, and he can tell you in a few minutes how to supply the world with a clean burning, inexhaustible fuel and free us from dependence on foreign oil.
Sound far fetched? Of course, but if we are ever going to move beyond hydrocarbons as our primary source of fuel we're going to have to start taking people like Wescott a lot more seriously.
Seas of Potential Fuel
Like so many scientists, Wescott sees hydrogen as the fuel of the future. Hydrogen can be "burned" in a fuel cell to produce electricity, and the only waste product is water so pure you can drink it. And hydrogen, the simplest and most abundant element in the universe, is everywhere. The seas are literally awash with the stuff. All you have to do is extract it from the water, and bingo, you've got the fuel of the future.
The technology for pulling hydrogen out of sea water is well understood, but there's a problem. It takes a lot of electrical energy to do it. So if you've got a lot of electricity, you can produce hydrogen, and that's the Catch-22 in all of this. If you've already got a lot of electrical energy, why bother with producing hydrogen to make more electricity?
And that brings us back to Gene Wescott. Several decades ago, when the world was searching for new types of energy, Wescott was dispatched from his campus in Fairbanks to a long string of islands that stretches for 1,100 miles from Alaska into the northern Pacific Ocean. The Aleutians are volcanic islands, many of them quite active today, and they are literally sitting on shallow beds of molten rock, surrounded by water.
The U.S. Department of Energy wanted to know if those desolate islands could be used to produce geothermal energy. The idea was that the hot areas beneath the surface might provide a continuous source of blistering hot water, which could in turn be flashed to steam and used to turn turbines and produce electricity. The precedent had been set in California and Iceland. California draws a small percentage of its electricity from geothermal power plants near San Francisco.
Energy for Centuries
So Wescott traveled out the Aleutians, drilling a few test wells along the way, and he found just what common sense would suggest should be there. The rocks beneath the surface were very, very hot.
"There are several obvious resources out there" which could be used to produce geothermal energy, Wescott says.
What he had found was an enormous potential source of energy, located in a remote area of the planet where only a handful of people live. Except for a few scattered native American villages, and an occasional U.S. military installation, the Aleutians are uninhabited. So here was the potential for a series of power plants in nobody's back yard, drawing electricity from natural resources that should produce energy for many, many centuries.
But here's the hitch: Why build power plants hundreds, or thousands, of miles away from any users? It isn't practical to run power lines from the Aleutians all the way to the major population centers of the western United States, so what Wescott really found was an enormous source of energy where nobody could use it
Hot dry rock goes supercritical
ReplyDeleteLOS ALAMOS, N.M., April 21, 2004 -- By proposing a method for using carbon dioxide under high pressure to extract energy from geothermal reservoirs, a University of California scientist working at Los Alamos National Laboratory has put a new twist on a historic Laboratory project. The proposed invention has the potential to take global geothermal energy science in new and exciting directions.
Based on expertise gained during the development of the Laboratory's Hot Dry Rock Project, Los Alamos geoscientist Donald W. Brown has proposed a method for producing geothermal energy using supercritical fluids such as carbon dioxide for the stimulation of the underground reservoir, production of the geothermal energy and heat transport. The Hot Dry Rock Project was a geothermal energy experiment that Los Alamos conducted between the years 1970 and 1996.
Brown's process stimulates underground reservoirs by pumping a supercritical fluid into a formation to fracture the rock. Generally, this is done at depths ranging from about 5,000 feet to about 20,000 feet below surface depending upon underground thermal conditions. At such depths, underground temperatures are in the range of roughly 200 to 600 degrees Fahrenheit in the western United States. A patent has been granted on the process.
Once the reservoir is accessed, the supercritical fluid is allowed to heat up and expand. It is then pumped out of the reservoir to transfer the heat to a surface power generating plant or other application requiring heat. The recovered fluid is sent back down into the reservoir and the heat-extraction process is repeated. Any loss of the carbon dioxide is slowly diffused in the Earth into the surrounding rock mass.
A supercritical fluid is a liquid that has been raised beyond a temperature and pressure at which the liquid and gas densities are equal -- its critical temperature and pressure. For carbon dioxide, the supercritical conditions are a pressure of 1,074 pounds per square inch and a temperature of 88 degrees Fahrenheit.
Carbon dioxide is useful as the supercritical fluid because it is readily available, economical and easy to store and handle when not in contact with water. It is also environmentally benign because it is relatively inert, nontoxic and nonflammable. The process can readily use waste carbon dioxide from industrial processes, locking up excess carbon dioxide, a known greenhouse gas. When carbon dioxide is used as the supercritical fluid, any mineral constituents such as silicates or chlorides within the reservoir are left behind as mineral precipitates since most minerals are not soluble in supercritical carbon dioxide.
Los Alamos National Laboratory is operated by the University of California for the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy and works in partnership with NNSA's Sandia and Lawrence Livermore national laboratories to support NNSA in its mission.
Los Alamos enhances global security by ensuring safety and confidence in the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction and improving the environmental and nuclear materials legacy of the cold war. Los Alamos' capabilities assist the nation in addressing energy, environment, infrastructure and biological security problems
--------------------------------------------------------------------------------
Geothermal Home Guide
ReplyDeleteWhat is it?
Geothermal energy is derived from heat stored beneath the surface of the earth. This natural source of energy was used even in the Paleolithic era. To extract the heat from the earth, pressurized water is forced through the rocks deep inside the earth. When water comes in contact with the hot areas of the earth, it heats up. When it’s taken out, the water is hot enough to be utilized for various purposes in homes and industries. Since ancient times, the Chinese and Romans have been known to use hot mineral springs for cooking, bathing, and therapy. Geothermal power is generated using three types of power plants, namely, flash steam, dry steam, and binary cycle.
Geothermal Technologies Program: A History of Geothermal Energy
History of Geothermal Power – Earthworm Tunneling
Geothermal Energy
How is it used?
Geothermal energy is used in a number of applications. It’s used in heating pumps in some homes in the United States and Sweden. Heat pumps are used to provide warmth and heat in the house. Countries such as Iceland and Turkey use it for the purpose of district heating. Countries such as China and Japan even use it for bathing. New Zealand has been using geothermal energy for agricultural applications, commercial purposes, water heating, and desalination. Electricity has been produced using geothermal energy for the past several decades. With the production of electricity, it’s utilized not just for heating but also for cooling as well as other purposes.
Uses of Geothermal Energy
Heat Pumps
Alternative Energy Source
Geothermal Energy Heat
Geothermal Resources in Iceland
Geothermal Energy Revealed
Pros and Cons
There are several advantages of geothermal energy. It is renewable, reliable, flexible, sustainable, and clean. This implies that there is no pollution unlike other sources such as coal. The overall cost of having a heating or a cooling system in homes turns out to be $30 to $50 a month. A disadvantage of such systems is that the initial cost related to the installation and design is high. Another disadvantage is that the piping system required for the complete set up is very large and may not be suitable for smaller places. In spite of this drawback, the positives would outweigh the negatives in the long run. Use of geothermal energy saves a whole lot of energy wastage. It’s at least 6 times more efficient than conventional sources of energy.
Advantages and Disadvantages
Heat Pump Systems
Geothermal Energy in the Home
Geothermal Energy Future
How does it run?
There are open and closed loop heat pumps. In an open loop system, water from a lake or a pond is pumped into the geo-thermal loop, which is a set of pipes. It is then directed back to its source after heat is exchanged between the heat pump and the geo-thermal loop. In a closed loop system, heat exchange occurs directly from the copper pipes. The cost of a heat pump with one ton capacity is about $2500, where an average home requires three such units. Geothermal pumps are quite durable and do not require much maintenance. There are fewer components in a geothermal system compared to other systems. The piping system usually comes with a guarantee of 25-50 years. In this sense, replacement is not required unless there are manufacturing defects in the unit installed.
Geothermal Heat Pumps
Geothermal Heat Pumps – Climate Lab
Diagram of a Geothermal System
--------------------------------------------------------------------------------
More information on Green Homes check out:
Green Homes
Making Your Home Green
Green Home Guidelines – NAHB Green Home Guide intro
Green Home is a Healthy Home
National Green Building Program
Green House: Milwaukee Office of Sustainability
Being Green in the Home
Go Green: Green tips
Green-It-Yourself
Geothermal Kids:
Kids Korner: Geothermal Energy
Geothermal: Energy and kids
EIA Energy Kids: Geothermal
Renewable Energy Lesson Plan – Kids Super Energy Saver Program
Geothermal Energy Basics
A History of Geothermal Energy in the United States - Part 1
ReplyDeleteFirst geothermal power plant, 1904, Lardarello, Italy.
Archaeological evidence shows that the first human use of geothermal resources in North America occurred more than 10,000 years ago with the settlement of Paleo-Indians at hot springs. The springs served as a source of warmth and cleansing, their minerals as a source of healing. While people still soak in shallow pools heated by the Earth, engineers are developing technologies that will allow us to probe more than 10 miles below the Earth's surface in search of geothermal energy. We invite you to study the timeline of the recent history of geothermal energy in the United States.
Important Events in the History of Geothermal Energy in the United States
Human beings have used geothermal energy in North America for at least 10,000 years. Paleo-Indians used hot springs for cooking, and for refuge and respite. Hot springs were neutral zones where members of warring nations would bathe together in peace. Native Americans have a history with every major hot spring in the United States.
1800 - 1850
1807
As European settlers moved westward across the continent, they gravitated toward these springs of warmth and vitality. In 1807, the first European to visit the Yellowstone area, John Colter, probably encountered hot springs, leading to the designation "Colter's Hell." Also in 1807, settlers founded the city of Hot Springs, Arkansas, where, in 1830, Asa Thompson charged one dollar each for the use of three spring-fed baths in a wooden tub, and the first known commercial use of geothermal energy occurred.
1847
William Bell Elliot, a member of John C. Fremont's survey party, stumbles upon a steaming valley just north of what is now San Francisco, California. Elliot calls the area The Geysers—a misnomer—and thinks he has found the gates of Hell.
Back to Top
Download A History of Geothermal Energy Research and Development in the United States, 1976-2006.
1851 - 1900
1852
The Geysers is developed into a spa called The Geysers Resort Hotel. Guests include J. Pierpont Morgan, Ulysses S. Grant, Theodore Roosevelt, and Mark Twain.
1862
At springs located southeast of The Geysers, businessman Sam Brannan pours an estimated half million dollars into an extravagant development dubbed "Calistoga," replete with hotel, bathhouses, skating pavilion, and racetrack. Brannan's was one of many spas reminiscent of those of Europe.
1864
Homes and dwellings have been built near springs through the millennia to take advantage of the natural heat of these geothermal springs, but the construction of the Hot Lake Hotel near La Grande, Oregon, marks the first time that the energy from hot springs is used on a large scale.
1892
Folks in Boise, Idaho, feel the heat of the world's first district heating system as water is piped from hot springs to town buildings. Within a few years, the system is serving 200 homes and 40 downtown businesses. Today, there are four district heating systems in Boise that provide heat to over 5 million square feet of residential, business, and governmental space. Although no one imitated this system for some 70 years, there are now 17 district heating systems in the United States and dozens more around the world.
1900
Hot springs water is piped to homes in Klamath Falls, Oregon.
Back to Top
See Part 2
A History of Geothermal Energy in the United States - Part 2
ReplyDelete1901 - 1950
1921
John D. Grant drills a well at The Geysers with the intention of generating electricity. This effort is unsuccessful, but one year later Grant meets with success across the valley at another site, and the United States' first geothermal power plant goes into operation. Grant uses steam from the first well to build a second well, and, several wells later, the operation is producing 250 kilowatts, enough electricity to light the buildings and streets at the resort. The plant, however, is not competitive with other sources of power, and it soon falls into disuse.
Hot Springs National Park in Arkansas is created.
1927
Pioneer Development Company drills the first exploratory wells at Imperial Valley, California.
1930
The first commercial greenhouse use of geothermal energy is undertaken in Boise, Idaho. The operation uses a 1000-foot well drilled in 1926. In Klamath Falls, Charlie Lieb develops the first downhole heat exchanger (DHE) to heat his house. Today, more than 500 DHEs are in use around the country.
1940
The first residential space heating in Nevada begins in the Moana area in Reno.
1948
Geothermal technology moves east when Professor Carl Nielsen of Ohio State University develops the first ground-source heat pump, for use at his residence. J.D. Krocker, an engineer in Portland, Oregon, pioneers the first commercial building use of a groundwater heat pump.
Back to Top
1951 - 1960
A geothermal power plant at The Geysers.
1960
The country's first large-scale geothermal electricity-generating plant begins operation. Pacific Gas and Electric operates the plant, located at The Geysers. The first turbine produces 11 megawatts (MW) of net power and operates successfully for more than 30 years. Today, 69 generating facilities are in operation at 18 resource sites around the country.
Back to Top
1961 - 1970
1970
The Geothermal Resources Council is formed to encourage development of geothermal resources worldwide.
The Geothermal Steam Act is enacted, which provides the Secretary of the Interior with the authority to lease public lands and other federal lands for geothermal exploration and development in an environmentally sound manner.
Back to Top
1971 - 1980
1972
The Geothermal Energy Association is formed. The association includes U.S. companies that develop geothermal resources worldwide for electrical power generation and direct-heat uses.
See Part 3
A History of Geothermal Energy in the United States - Part 3
ReplyDelete1973
The National Science Foundation becomes the lead agency for federal geothermal programs.
1974
The U.S. government enacts the Geothermal Energy Research, Development and Demonstration (RD&D) Act, instituting the Geothermal Loan Guaranty Program, which provides investment security to public and private sectors using developing technologies to exploit geothermal resources.
1975
The Energy Research and Development Administration (ERDA) is formed. The Division of Geothermal Energy takes over the RD&D program. The Geo-Heat Center is formed. The center, located at the Oregon Institute of Technology, disseminates information to potential users and conducts applied research on using low- to moderate-temperature geothermal resources. The U.S. Geological Survey releases the first national geothermal resource estimate and inventory.
1977
The U.S. Department of Energy (DOE) is formed.
1978
The Public Utility Regulatory Policies Act (PURPA) is enacted. PURPA encourages the development of independent, nonutility cogeneration and small power projects by requiring electric utilities to interconnect with them. The act results in the development of several water-dominated resources.
Geothermal Food Processors, Inc., opens the first geothermal food-processing (crop-drying) plant in Brady Hot Springs, Nevada. The Loan Guaranty Program provides $3.5 million for the facility.
A hot dry rock geothermal facility is created and tested in Fenton Hill, New Mexico, with financial assistance from DOE. The facility generates electricity two years later, in 1980.
1979
The first electrical development of a water-dominated geothermal resource occurs, at the East Mesa field in the Imperial Valley in California. The plant is named for B.C. McCabe, the geothermal pioneer who, with his Magma Power Company, did field development work at several sites, including The Geysers.
DOE institutes funding of direct-use demonstration projects. Among the beneficiaries of this effort are several office buildings, district heating systems, and agribusinesses.
1980
TAD's Enterprises of Nevada pioneers the use of geothermal energy for the cooking, distilling, and drying processes associated with alcohol fuels production. UNOCAL builds the country's first flash plant, generating 10 MW at Brawley, California.
Back to Top
1981 - 1990
1981
With a supporting loan from DOE, Ormat successfully demonstrates binary technology in the Imperial Valley of California. This project establishes the technical feasibility of larger-scale commercial binary power plants. The project is so successful that Ormat repays the loan within a year.
The first electricity is generated from geothermal resources in Hawaii. The Department of Energy demonstrates the production of electricity from moderate temperature geothermal resources using binary technology at Raft River, ID.
1982
Economical electrical generation begins at California's Salton Sea geothermal field through the use of crystallizer-clarifier technology. The technology resulted from a government/industry effort to manage the high-salinity brines at the site.
1984
A 20-MW plant begins generating power at Utah's Roosevelt Hot Springs. Nevada's first geothermal electricity is generated when a 1.3-MW binary power plant begins operation.
The Heber dual-flash power plant goes online in the Imperial Valley of California with 50 MW.
1987
Geothermal fluids are used in the first geothermal-enhanced heap leaching project for gold recovery, near Round Mountain, Nevada.
1989
The world's first hybrid (organic Rankine/gas engine) geopressure-geothermal power plant begins operation at Pleasant Bayou, Texas, using both the heat and the methane of a geopressured resource.
See Part 4
A History of Geothermal Energy in the United States - Part 4
ReplyDelete1991 - 2000
1991
The Bonneville Power Administration selects three sites in the Pacific Northwest for geothermal demonstration projects.
1992
Electrical generation begins at the 25-MW geothermal plant in the Puna field of Hawaii.
1993
A 23-MW binary power plant is completed at Steamboat Springs, Nevada.
1994
DOE creates two industry/government collaborative efforts to promote the use of geothermal energy to reduce greenhouse gas emissions. One effort is directed toward the accelerated development of geothermal resources for electric power generation; the other is aimed toward the accelerated use of geothermal heat pumps.
1995
Integrated Ingredients dedicates a food-dehydration facility that processes 15 million pounds of dried onions and garlic per year at Empire, Nevada. A DOE low-temperature resource assessment of 10 western states identifies nearly 9000 thermal wells and springs and 271 communities collocated with a geothermal resource greater than 50ºC.
2000
DOE initiates its GeoPowering the West program to encourage development of geothermal resources in the western U. S. An initial group of 21 partnerships with industry is funded to develop new technologies.
Back to Top
2001 - 2002
2001
GeoPowering the West brings together representatives from industry and agencies such as the U.S. Bureau of Land Management and U.S. Forest Service to identify major barriers to geothermal development in the west. The report of the proceedings listed specific action items and recommendations. Several of the recommendations pertained to leasing, permitting, and access to federal lands.
Secretary of the Interior Gail Norton convened a renewable energy summit with officials from DOI, DOE, and other agencies to identify actions required to support renewable energy development. Recommendations specific to geothermal emerged from the meeting, including a mandate to BLM to accelerate issuing leases and permits on federal lands.
2002
Organized by GeoPowering the West, geothermal development working groups are active in five states — Nevada, Idaho, New Mexico, Oregon, and Washington. Group members represent all stakeholder organizations. The working groups are identifying barriers to geothermal development in their state, and bringing together all interested parties to arrive at mutually beneficial solutions.
2003
2003 The Utah Geothermal Working Group is formed.
Our thanks to the Geo-Heat Center for providing substantial information about the history of geothermal energy.