Geothermal energy is the heat produced by the molten core under the Earth’s crust. This heat is continuously produced through decay of radioactive materials such as uranium and potassium.
The heat produced within the first 33,000 feet of the Earth’s surface produces 50,000 times more energy than all the oil and natural gas in the world combined. That seems like a pretty good reason to try and harness the power of geothermal energy.
Tectonic plate boundaries and places where the crust is thin, have the highest underground temperatures and you don’t have to go as far to reach the heat being produced.
With a possibility of more than 400% efficiency and nearly zero emissions, it is not surprising that geothermal energy is considered one of the most efficient, cost effective, and environmentally friendly sources of energy.
Geothermal energy is an effective, inexhaustible, and renewable resource. This article is going to discuss the advantages of geothermal energy.
1. Environmentally Friendly
Geothermal plants emit 0.1 to 0.2 pounds of carbon dioxide for every kilowatt-hour. Compare that with coal plants that emit 1.4 and 3.6 pounds of carbon dioxide for every kilowatt-hour, and geothermal energy looks like a pretty good choice for energy production.
The hot water pumped from underground by geothermal heat pumps will often contains high levels of sulfur, salt, and other minerals. However since most geothermal plants have closed loop systems, in which the water extracted is pumped back into the geothermal reservoir, there is no water pollution.
Geothermal plants emit zero nitrogen oxides, very little sulfur oxide, and very low amounts of carbon dioxide. These gases are not emitted during production because there is no combustion, but are natural constituents of all geothermal reservoirs.
One possible solution to the very low amounts of carbon dioxide produced by geothermal energy is to use it as a growth stimulant in geothermally heated greenhouses.
Geothermal energy also has the smallest land-use footprint per kilowatt than any energy generation technology currently available. An entire geothermal field may use 1-8 acres of land per megawatt compared to 5-10 acres for nuclear energy and 19 acres for coal.
The state of Nevada has been able to save 4.5 million barrels of oil and avoid 2.25 million tons of carbon dioxide emissions annually, by using their 300 MW geothermal power plant.
2. High Efficiency and Low Maintenance
Geothermal energy is considered the most energy efficient and cost effective energy system available, with the geothermal heat pump being four to five times more efficient than a gas furnace.
Efficiency is rated according to the coefficient of performance, COP for short. It is basically a way to determine how much energy the system produces compared to how much it uses.
Geothermal heat pumps have a COP of 3-4.5, meaning that for every 1 unit of electricity used 3 to 4.5 units are created. In other words, geothermal heat pumps have a potential of more than 400% efficiency, while a fossil fuel furnace is only around 78-90%.
The ability to have 400% efficiency comes from the fact that the energy is being harnessed, rather than captured through combustion of fossil fuels.
According to the Office of Energy Efficiency and Renewable Energy, the operating and maintenance cost of a geothermal plant range from $0.01 to $0.03 per kWh. A home system can be considered almost maintenance free.
The buried loop that carries the water will last for at least 50 years, and the other half of the system that includes the fan, pump, and compressor are housed indoors, protected from the outdoor elements, and should last at least 20 years.
3. Cost Effective and Reliable
The average lifespan of a geothermal heating system is 22 years, with costs being recouped in three to seven years. Once costs are recouped the average household can save anywhere from 30%-70% on energy bills.
Geothermal energy cost the least to generate one million BTUs. Geothermal heating pumps cost only $6.70 per one million BTUs, with natural gas at $15.48, propane at $29.73, and fuel topping out at $30.21 per one million BTUs.
The average availability of geothermal power plants are 90% or higher, whereas coal plants average only 75%. Meaning geothermal plants are available 90% of the time, most operating around 98%.
Geothermal plants can operate 24 hours a day regardless of weather patterns and environmental conditions, and they are not subject to the voltage swings and unpredictability that plague non-renewable energy sources.
Geothermal plants are scalable, meaning that a small plant can be economically built for applications within a community or utility-scale facilities on the multi-MW scale can also be economically built.
4. Supports Local Economic Development
Unlike the fossil fuel technologies, renewable energy is a lot more labor intensive, creating more jobs on average for each production facility generated.
Many of the geothermal resources that can be used for energy production are located in rural areas, many of which suffer from economic depression and unemployment. Geothermal development brings jobs and tax payments that provide significant economic advantages.
Some of the different types of jobs create by geothermal energy production include careers in science and technology, management and administrative support, construction, manufacturing, and operations.
The Geysers Geothermal Complex in California created 225 part-time jobs and 425 full time jobs. The geothermal industry as a whole is creating approximately 1.7 jobs for ever megawatt of power production capacity in power plant maintenance and operations as well as other areas in geothermal development including research, legal and government regulators, and al development.
Geothermal power plants also create temporary jobs in manufacturing and construction. With 3.1 construction jobs per megawatt and 3.3 manufacturing jobs per megawatt installed.
According to the Geothermal Energy Association, in 2005 the United States passed the Geothermal Steam Act Amendments requiring 25% of revenues produced from geothermal leasing and production to be allotted to state and local governments. Nevada received $7.5 million in 2008, and put all that money towards funding public schools.
In 2011 California reported revenues of $4 million with a cumulative total of $188 million since 1972. In 2013 alone, geothermal power generated $15 million in royalties and rents from federal land use in the United States.
Geothermal plants can also draw in tourist. The most popular tourist destination in Iceland a geothermal spa named the Blue Lagoon that is connected to the Svartsengi power plant, bringing in more than 75,000 visitors since its opening in 2001.
Geothermal energy creates small to zero emission compared to coal and oil plants, and the environmental impacts are significantly less than current methods of energy production. From and economic stand point, geothermal energy is very practical and feasible.
Geothermal energy could completely replace oil and natural gas heating and cooling systems in many areas, and reduce annual costs and CO2 emissions, as well as other dangerous pollutants.
By increasing the availability of geothermal energy and other natural resources, countries can improve their ability to control their economic future and improve their national security, while at the same time conserving oil and natural gas resources for higher value uses such as liquid fuels for transportation, chemical feedstock, and pharmaceuticals.
In the United States, lack of development is not due to economic barriers but instead political, structure, and policy barriers are preventing development. The people as a whole need to play an active role in producing clean, safe, and renewable energy, and geothermal energy is being ignored and underestimated.
Do you have an experience with geothermal thermal energy that you would like to share? Leave a comment and continue this conversation by sharing your experience.
Featured Image Credit: anne beaumont @ Flickr