The global community consumes an incredible amount of energy. The burning of fossil fuels remains the primary way electricity is generated, but it is also one of the leading contributors to greenhouse gases. Finding reliable and renewable sources of energy is the key to a sustainable future. This is where geothermal energy comes into play.
Geothermal energy can be explained simply by its name, which derives from the Greek words "geo," meaning Earth, and "therme," meaning heat. The heat is directly below the Earth's surface, making it a universal resource. The most active geothermal spots are found near fault lines and volcanoes but also occur where there are hot springs, geysers and geothermal reservoirs. It can be harnessed cleanly and efficiently. Here are 10 reasons why geothermal energy is a viable solution to a rapidly expanding global crisis.
10: It's Renewable
Geothermal energy is collected by tapping into hot water and steam trapped beneath the Earth's surface. This water and its steam are known collectively as hydrothermal energy. Geothermal energy is considered to be limitless. Its heat comes from the core of the Earth, a 24-hour-a-day, 365-day-a-year energy source. The amount of heat extracted for use is negligible compared with the Earth's total heat content, so it's virtually impossible to make any significant impact on the inner temperature of the planet during the extraction process [source: U.S. Department of Energy]. Simply put, there is an inexhaustible supply of heat. Unless the core of the planet turns cold (which presents more pressing problems for life on Earth) it's safe to say that geothermal power is completely renewable.
9: It's Convenient
Although areas around fault lines, geothermal reservoirs and volcanoes are easier to tap into, geothermal heat can literally be found everywhere. This is just one reason it's so convenient. Here's another: There's a constant supply. Geothermal energy is not dependent upon factors like sun or wind to generate power. Let's not forget that it's also local -- geothermal energy never has to be imported.
If you live in the western United States, you're in luck. American harvesting of geothermal power occurs primarily out west and in Hawaii, where water is closer to the Earth's surface, which allows for easier drilling. This means your power company is more likely to be able to buy some of its electricity from a geothermal plant, which reduces dependence on nuclear power plants. That's good, because they produce toxic waste; it also reduces dependence on fossil fuels, which produce carbon emissions.
8: A Cleaner Power Plant
There are three main types of geothermal plants: dry steam, flash steam and binary. All employ practices that maximize production while minimizing environmental impact. Each uses a different but related technique to power turbines, which in turn generate electricity without spewing tons of toxins into the atmosphere.
- Dry steam plants use underground steam, piped directly to the power plant, where it enters a turbine/generator. The only dry steam plant in the U.S. is in California.
- Flash steam plants are the most common type of geothermal plant, using geothermal reservoirs for power. Extremely hot water flows upward, and as it flows it is turned into steam, which powers the turbine/generator. Water is then injected back into the reservoir, making this a very sustainable power plant.
- Binary plants use water to boil a working fluid (usually an organic compound) that is vaporized and used to turn a turbine. Excess water is injected back into the ground, conserving water.
7: Geothermal Energy Has Many Uses
You might be surprised to learn farmers and agribusinesses were two early adopters of geothermal energy. Italian farmers have used it for hundreds of years to heat water for winter crops. Geothermal energy is also used to heat and humidify greenhouses. A food dehydration plant in Empire, Nev., that's powered by geothermal energy dries 15 million pounds of onions and garlic each year [source: U.S. Department of Energy]. Dairy farmers have used it to power milk pasteurizers and fish farms gently heat their water with it.
In the U.S., geothermal energy has heated homes, backyard swimming pools and commercial buildings for more than a century. Municipalities use it to melt snow and ice on sidewalks and roads. This cuts down on the number of snowplows and sanders, saving communities money and reducing fossil fuels. Colleges and universities are getting in on the action, using the government's recent $400 million grant to convert buildings over from coal-fired plants [source: Ramde].
Perhaps the question that should be asked is: "Is there anything you can't power with geothermal energy?"
6: GHPs are Money in the Bank
Rare is the person who enjoys throwing money out the window. But if your home heating and cooling systems are inefficient, that's exactly what you're doing. A geothermal heat pump can help you solve the problem and keep dollars in your wallet.
A geothermal heat pump (GHP) is a heat-mover. In the winter it takes heat from a warm area and transfers it to a cool one. The reverse occurs in the summer. It's efficient, clean and cuts costs. If you live in the U.S. you're eligible for a 30 percent tax credit for installing one in your home [source: U.S. Department of Energy]. Many other countries offer similar incentives. The installation of a GHP is not a DIY project; you'll need a professional to do it. But the money spent up front comes back to you over the long haul.
Every GHP has a component called a "desuperheater." In the summer the desuperheater uses the heat from your house to warm your water. What's so cool about that? It's essentially free hot water in the summertime! The U.S. Department of Energy estimates a GHP will give you an annual savings of 30 to 60 percent on utilities.
When it comes to saving bucks, you can't beat the heat.
5: It's Got a Bright Future
Geothermal energy production is quickly becoming a powerhouse on the alternative energy scene. Between 2005 and2010 the industry experienced an exponential growth rate of 4.25 percent per year [source: Sanyal]. Technological advances are pushing geothermal energy to new depths. Enhanced Geothermal Systems (EGS) significantly increased the options for plant locations [source: U.S. Department of Energy]. EGS uses dry rock deep in the Earth to extract heat. In the U.S. the ability to drill deeper means production can move eastward, expanding the geothermal market.
The developing world is also benefiting from geothermal energy. The Philippines produces 23 percent of its power this way and hopes to increase that production to 60 percent by 2013. In Africa, Kenya is tapping its geothermal potential in the Great Rift Valley [source: Dorn].
These advances create more than clean energy -- they create jobs. According to the National Resources Defense Council, the "near-time development of 5,600 megawatts of geothermal power" would create nearly 100,000 jobs in the United States. Engineers, architectures, construction workers (welders, plumbers, pipe fitters etc), and scientists are just some of the specialists required to research, design and build geothermal plants.
4: Hydrated but not Hydroelectric
Hydroelectric (or hydropower) has been in use for more than 2,000 years. Seven percent of energy production in the United States is produced by this method. Considered clean in terms of emissions and greenhouse gases, there is a drawback: Hydroelectric plants dam rivers and streams to create energy. Diverting water disrupts fish spawning and compromises stream-side flora and fauna. In Canada, the La Grande project has already submerged 10,000 square kilometers of land. If the rate of expansion continues, the area of land in northern Quebec submerged by the project will be larger than Switzerland [source: Baird].
Unlike hydroelectric plants, geothermal plants don't dam natural waterways to flood land to produce power. The hot water and steam lies below the Earth's surface and is processed in contained areas. In closed system geothermal plants, water is re-injected into the ground and used again at a later date. Wells are fortified to prevent water leakage, making geothermal energy production less harmful to local water sources and the people, plants and animals living close by.
3: It's Reliable
Geothermal energy is considered to be incredibly reliable. While it's true that power production can vary depending upon the available hydrothermal resources, a typical geothermal plant operates at 95 percent to 99 percent "plant availability." What does that mean? If it has permission to operate it can be counted on to produce a steady stream of power with little or no interruptions [source: Krief and Goswami]. A typical coal plant operates at 75 percent of operating ability.
Geothermal energy holds its ground when compared with other forms of alternative energy. A big advantage geothermal energy has over wind power is that it doesn't grapple with "dispatchability." The Earth provides a constant source of heat. Wind turbines are dependent on wind: No wind means no energy. And even when the wind blows, its speed is variable, which makes it difficult to control. The same holds true for solar power, production of which dips on cloudy days., There is also a lot less that can go wrong with a geothermal power plant, which has day-to-day operations much less complex than those of other types of plants. Every geothermal plant built in the past 100 years is still in use [source: Energy Consumers Edge].
2: Impact on the Local Environment
In the U.S., geothermal plants are required to meet strict local, state and federal environmental laws to protect wildlife and vegetation. The Geysers, a geothermal facility in California, even recycles wastewater from a nearby treatment facility. Eleven million gallons are pumped each day into one of their geothermal reservoirs. Thick casings help prevent cross-contamination with local watersheds [source: Kagel, Bates and Gawell].
Power plants often create a good deal of racket, and geothermal plants must adhere to local noise pollution regulations. The noise from the cooling fans is minimal and sound mufflers are often installed around equipment [source: Geothermal Energy Association]. It's been noted that decibel levels of a geothermal plant are equivalent to "near leaves rustling from the breeze" [source: Kagel, Bates and Gawell]. Geothermal plants are also designed to blend in to their surroundings. They cannot be built on federally protected lands. In fact, plants are often built on multiple-use land that doubles for farming and recreation. This helps to minimize sprawl and preserve open spaces [source: Kagel, Bates and Gawell].
1: A Cleaner Form of Energy
All forms of alternative energy impact the environment on some level by generating waste either directly or indirectly. Geothermal energy is a viable and simple option. It taps into an unlimited supply of heat from the Earth and leaves little pollution in its wake.
One of the biggest advantages to geothermal energy is the production process itself. There is no burning of fossil fuels such as oil, coal or gas during extraction. Plants are powered by steam. The plumes seen rising from flash steam plants are vapor emissions, not smoke. Binary plants release zero emissions. Everything that is brought to the surface is injected back into the ground to be used again [source: Union for Concerned Scientists]. There is nothing needed to produce geothermal energy that needs to be transported from another location. The power source is quite literally underneath the feet of the power plant.
For more information on geothermal energy and other renewable energy sources, visit the links on the following page.
Lots More Information
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- Baird, Stuart. “Hydro-Electric Power.” Local Government for Sustainability. (August 30, 2010). http://www.physics.ohio-state.edu/~kagan/phy367/P367_articles/HydroElectric/hydroelectric.html
- Biello, David. “Drilling for Hot Rocks: Google Sinks Cash Into Advanced Geothermal Technology.” Scientific American. August 20, 2008. (August 31, 2010) http://www.scientificamerican.com/article.cfm?id=google-invests-in-geothermal
- Dorn, Jonathan, G. “World Geothermal Power Generation Nearing Eruption.” Earth Policy Institute. August 19, 2008. (August 30, 2010) http://us.oneworld.net/article/357012-plugging-earths-heat-ii
- Energy Consumers Edge. “Pros and Cons of Geothermal Energy.” April 2007. (August 30, 2010) http://www.energy-consumers-edge.com/pros_and_cons_of_geothermal_energy.html
- Environmental Literacy Council. “Hydroelectric Power.” April 8, 2008. (August 31, 2010) http://www.enviroliteracy.org/article.php/59.html
- Geothermal Energy Association. “Geothermal Basics: Environment.” (August 31, 2010) http://www.geo-energy.org/geo_basics_environment.aspx#quiet
- Kagel, Alyssa. Bates, Diana. Gawell, Karl. “A Guide to Geothermal Energy and the Environment.” Geothermal Energy Association. April 2007. (August 30, 2010) http://www.geo-energy.org/reports/Environmental%20Guide.pdf
- Krief, Frank. Goswami, D. Yogi. “Handbook of Energy Efficiency and Renewable Energy.” CRC Press. Copyright 2007.
- National Resources Defense Council. “Renewable Energy for America.” (August 30, 2010) http://www.nrdc.org/energy/renewables/geothermal.asp
- Ramade, Dinesh. “ Drive for Geothermal Power Heats Up on US Campuses.” December 6, 2009. (August 31, 2010) http://abcnews.go.com/Business/wireStory?id=9263642
- Sanyal, Subir, K. “Future of Geothermal Energy.” February 2010. (August 30, 2010) http://pangea.stanford.edu/ERE/pdf/IGAstandard/SGW/2010/sanyal.pdf
- Scientific American. “Beyond Fossil Fuels: Daniel Kunz on Geothermal Energy.” April 24, 2009. (August 30, 2010). http://www.scientificamerican.com/article.cfm?id=energy-kunz-us-geothermal
- Union Of Concerned Scientists. “Environmental Impact of Renewable Energy Technologies.” http://www.ucsusa.org/clean_energy/technology_and_impacts/impacts/environmental-impacts-of.html
- Union of Concerned Scientists. “How Geothermal Energy Works.” December 16, 2009. (August 30, 2010) http://www1.eere.energy.gov/geothermal/powerplants.html
- U.S. Department of Energy. “Geothermal FAQs.” January 13, 2006. (August 31, 2010) http://www1.eere.energy.gov/geothermal/faqs.html
- U.S. Department of Energy. “A History of Geothermal Energy in the United`States.” November 11, 2006. (September 5, 2010) http://www1.eere.energy.gov/geothermal/history.html
- U.S. Department of Energy. “Hydrothermal Power Systems.” July 6, 2010. (August 31, 2010) http://www1.eere.energy.gov/geothermal/powerplants.html
- U.S. Department of Energy. “Selecting and Installing a Geothermal Heat Pump System.” December 30, 2008. (August 31, 2010) http://www.energysavers.gov/your_home/space_heating_cooling/index.cfm/mytopic=12670
- Watson, Stephanie. “How Geothermal Energy Works.” How Stuff Works. (August 30, 2010) http://science.howstuffworks.com/environmental/energy/geothermal-energy.htm