One of the biggest issues facing humanity as we continue into the twenty-first century is the problem of energy. As it is now, humanity is consuming fossil fuels and other resources at an alarming rate. This leads not only to environment destroying pollutants, but also a deficit in these precious resources. Environmentalist and others have tried to solve this problem in many ways including; solar energy, windmills, and watermills. However, why shouldn’t we simply use the vast amount of energy available beneath our very feet? Geothermal energy should be further explored because; our current energy system is failing rapidly, geothermal energy is an efficient form of energy, and it isn’t as environmentally taxing as other methods of obtaining energy.
Before we begin to invest in geothermal energy, we must first understand what it is and how it works. Put simply, geothermal energy is using the heat captured in the earth to meet our needs. This heat was generated when the earth was formed by radioactive decay of minerals, and from solar energy absorbed at the surface of the earth. (BBC) Since then it has been contained under the earth’s crust. Geothermal heating is available anywhere there is continental crust, but greater amounts of energy are available at areas near tectonic plate boundaries where volcanic activity is common.(BBC) Such areas include the Western U.S., the eastern coast of Japan, and most of Iceland.
The easiest and most common way to harvest geothermal energy is with the use of a heat pump. Heat pumps are used to transfer heat both to and from the desired area (building) to the earth. Heat pumps are some sort of device that transfers energy from the “source” to the “sink”. (UCS) The source is always at a cooler temperature than the sink. Heat pumps vary by their type, but most operate through a fairly simple process. To begin with all heat pumps must have an indoor unit (evaporator coil) and an outdoor unit (condenser). In normal system, the pump use a substance called refrigerant to carry the heat from one area to another (outside to inside or vice versa).
One of the greatest benefits of using geothermal heat pumps is you can pick one that specifically fits your needs. The first type of geothermal heating pump is the horizontal closed-loop system. This type of system is usually used for residential homes where there is a lot of available space. (UDE) It is also convenient for horizontal systems if they are implemented in a residence pre-construction, since installation is so tedious. In this system two pipes four and six feet deep are installed in a loopy slinky fashion. (UDE) This allows for more length of pipe to be installed without taking up that much space making it perfect for smaller residential buildings.
The second type of geothermal heat pump is the vertical closed-loop system. These are usually used in large commercial building where there isn’t a lot of land available for horizontal pipes. (UDE) Vertical system heat pumps are often used for schools and community buildings. There system is basically the same as the horizontal system except their pipes go deeper which takes up less room underground horizontally. “This is the most common type of geothermal heat pump system used worldwide.” (UDE)
The third type of geothermal heat pump is the pond/lake closed-loop system. This is the cheapest type of geothermal heating pump due to the water providing easily collected energy. (UDE) However, your property must meet some pretty specific condition in order to use this system. To use this system, the property you want to heat must be within twenty-five yards of a significant body of water such as a pond or lake. (UDE) It is also important to make sure the water source isn’t contaminated with toxins that can corrode the systems piping. If you meet these requirements, then pipes are run underground from the property to the water source and placed at least eight feet under the water. (UDE) This is to prevent freezing of the pipes. Though this geothermal heat system does need fairly specific conditions in order to thrive, its general inexpensiveness makes it one of the more popular geothermal heat systems.
Though many people use one of the above systems, many are now beginning to use a hybrid system utilizing a geothermal heat system along with some other form of heating /cooling. ‘This idea of mixing and matching has become increasingly popular in areas where the cooling needs far outweighs the heating needs of a residence.” (UDE) This system allows a residence to use geothermal to heat their home and another form of energy to cool their home. This plays to the strength of geothermal energy as heating over cooling.
One reason geothermal energy should be further invested in is the rapidly failing nature of our current energy system. The current staple of our current energy system is the burning of fossil fuels. This leads to many problems that are not only environmental, but practical as well. The most pressing problem associated with the burning of fossil fuels is the vast amount of effect it has on our environment. One such effect is that the release of greenhouse gasses that the burning of fossil fuels causes. As the amount of industry in the world increases so does these companies burning of fossil fuels. (BBC) This has led to the depletion of the ozone layer commonly referred to as “global warming”. These rising temperatures caused by greenhouse gas have had a dramatic effect on many environments throughout the world.
Global warming may not seem like such a big deal, but it has far ranging consequences throughout the world. One example of this is that increased temperatures in the north have mad way for disease carrying insects to migrate north carrying their sickness with them. “Over 64,000 cases of malaria have been reported in Peru this year, almost half in the Amazon region of the country as the disease is carried further north by mosquitoes.” (UCS) Another example global warming’s impact is as the temperature in the oceans warms, it could lead to an increase in hurricanes which are more present in warmer water. The next example of global warming’s impact is the increased risk in extended droughts in warmer climates. For example “the country of Morocco has experienced more droughts in the past decade than in any previous decade’. (UCS) This shows how global warming has directly led to an increase in droughts in this African country. Yet another example of the possible effects of global warming is an increased chance for wildfires. These wildfires have become more and more common as the earth’s temperature has increased. For example, “in 2007, more than 3,000 fires brought destruction to Southeastern Europe thanks to a long summer that created arid and parched conditions – a situation that would become normal as a consequence of the greenhouse effect.” (UCS) These are some of the lesser known effects of the greenhouse gasses released by the burning of fossil fuel.
The most prominent impact of global warming is the melting of the polar ice caps. As the ice caps continue to melt, it will lead to four separate issues that will demand our attention. Firstly, the melting has led to an increase in sea level at a drastic rate of 2 mm per year. ‘Eventually if all the ice caps melt, the ocean level could rise as much as 230 ft.” (BBC) This could lead to vast amounts of erosion on shorelines throughout the world. The second issue caused by the melting of the polar ice caps is that their mixing into ocean waters will make them less salty. The third issue associated with the melting of the ice caps is that the higher temperatures will lead to changing landscapes and eventually the extinction of several species of animals. (BBC) All the animals that currently live in the Arctic Circle where most ice caps are located would have to rapidly adapt to the changing environment in order to survive. The final issue caused by the melting of the ice caps is that as they start to disappear, it could lead to even more global warming. This is due to the fact that the “white” ice caps reflect the light from the sun significantly lowering the temperature of the earth. (BBC) However, if the ice caps were gone, this sunlight would not be reflected leading to a vast increase in the earth’s temperature which will lead to even more environmental issues. These are the main issues that will be a direct result of the polar ice caps melting as a result of global warming.
Though the environmental effects of the burning of fossil fuels is more widely known, there are also some practical issues with this current system of acquiring energy. To begin with, the prominent use of fossil fuels has severely weakened the economy of the United States. This is due to the fact that the U.S. government imports a vast amount of oil and other fossil fuel products. This causes an imbalance in the import/export balance of our economy. For example, ‘In 2004, almost sixty percent of petroleum products used in the United States were imported from other countries.” (GEA) This problem will only continue to increase as the need for energy increases over time.
Another practical issue of the use of fossil fuels is that they’re not a renewable resource. In contrast to geothermal energy, fossil fuels take an inordinate amount of time to replenish. “It takes about ten million years for a significant amount of oil, petroleum, or coal to develop.” (GEA) Obviously, humanity can’t rely primarily on a resource that has such a long renewal period. To show how long ten million years is, “going back that far from present day, the British Isles were still in the Southern Hemisphere”. (GEA) This example just shows the expansive amount of time it takes fossil fuels to form. These examples show that fossil fuels cannot be an efficient source of energy in a world where an increasing population is continuously demanding more and more energy. Therefore, we must begin researching other more renewable sources of energy.
The next reason we should further invest in geothermal energy is that geothermal energy is a very efficient energy source. One thing that makes geothermal energy so effective, is that it can be collected basically anywhere. This is possible because despite the temperature of the surrounding area, the ground typically stays at a pretty constant temperature. (GEA) Though the ground temperature does very slightly depending on the latitude, the temperature where geothermal energy can no longer be collected is well below any temperature ever collected in the United States. This allows geothermal energy to be collected basically anywhere.
Another reason geothermal energy is so effective is it available for use not only in the winter, but in the summer as well. This is due to the fact that the pumps can not only add heat from the ground into your house during the colder months, but they can also remove heat from your house during the warmer months using the same process. (GEA) The next reason geothermal energy is so effective is it can obtain most of the heat it produces directly from the heat from the ground. About seventy percent of the energy produced by geothermal heat pumps is renewable energy obtained from the ground according to recent studies. (GEA) Yet another reason geothermal energy is more efficient than most forms of energy is that it tends to be less noisy than other methods such as electric heating. 4 out of 5 people who have used geothermal heat pumps claim it is vastly quieter than their previous heating system. (GEA) These are just a few examples that show how efficient an energy source geothermal heating really is.
The third reason geothermal energy is so efficient is it can be used for a variety of things. Geothermal energy can be used in four basic ways. Geothermal energy is primarily used in a direct fashion. “In areas where hot springs or geothermal reservoirs are near the Earth’s surface, hot water can be piped in directly to heat homes or office buildings.” (HSW) After the heat is extracted from the water, the water is sent down another pipe back into the Earth. Though this is the most widely used mode of geothermal energy, it isn’t the only mode.
Another way geothermal energy can be used is in the form of geothermal heat pumps. These pumps collect the heat that naturally occurs in the ground and transfer it to a residence. “Fluid circulates through a series of pipes (called a loop) under the ground or beneath the water of a pond or lake and into a building. An electric compressor and heat exchanger pull the heat from the pipes and send it via a duct system throughout the building.” (HSW) One attractive element of this form of geothermal energy is that not only can it be used to heat in the summer, but also in order to cool in the summer. This makes this a very appealing form of geothermal energy.
The next form of geothermal energy is that harnessed for dry steam plants. “Hot steam is piped directly from geothermal reservoirs into generators in the power plant.” (HSW) This is the most “corporal” form of geothermal energy that is currently in use. As our dependence on fossil fuels causes more and more problems, you can expect the use of this form of geothermal energy to increase.
The final way geothermal energy is harnessed is through the use of a binary cycle plant. These plants are commonly used in the production of electricity. “Moderately hot geothermal water is passed through a heat exchanger, where its heat is transferred to a liquid (such as isobutene) that boils at a lower temperature than water. When that fluid is heated it turns to steam, which spins the turbines.” (HSW) This has become a common practice as geothermal energy has become more popular.
The main practical issue associated with geothermal energy is that it isn’t as cost-efficient as other forms of energy. Whether you’re establishing a large geothermal power plant or simply setting up a residential system, geothermal energy is initially significantly more expensive than other forms of energy such as natural gas or electric. (GTA) If you’re establishing a plant you must pay for the development of the site, construction of the power plant, and the hiring of skilled professionals who can operate the plant. (GTA) If you want to set up a residential geothermal energy system, you will need to fund labor and the fitting of long pipes under the ground. (GTA) Also if any problems occur with your system, it is important to repair them quickly in order to prevent ground water contamination.
However, these often pricy initial costs can be recovered within a few years due to the advantages of geothermal heating. For example, “Governments of various countries offer incentives and rebates to residential as well as industries to make use of geothermal energy where it is possible to harness that energy.” (GTA) These rebates can often pay for the setup costs of these systems within a few years of their setup. In addition, studies show that the cost of maintaining a geothermal energy system is significantly less than an energy system operated by the burning of fossil fuels. According the geologist at UCLA, “in a five year span those using an average heating system paid up to 17 more than those who have owned a geothermal heating system for the same five years.” (GTA) This is some of the cost issues associated with geothermal heating.
The final reason we should invest further in geothermal energy is that it simply isn’t as environmentally taxing as other forms of energy we can use. For example, if the closed-looped system of geothermal energy are used the system becomes totally benign. This allows the air pollution normally associated with the production of energy to be completely disregarded. (UCS) However, do to the expensiveness of closed-looped systems they still aren’t that commonly used. Unfortunately due to the costs of closed-loop systems, environmentally damaging open-loop systems are more commonly used. These systems “can generate large amounts of solid wastes as well as noxious fumes.” (UCS) Gasses and other pollution causing material leaks into the water as it leaves the rocks. The large amounts of chemicals released when geothermal fields are tapped for commercial production can be damaging to people living and working nearby.
One way the environmental impact of geothermal energy is reduced is by the use of scrubbers. Scrubbers are metal devices that reduce air emissions. However, “scrubbers produce a watery sludge high in sulfur and vanadium, a heavy metal that can be toxic in high concentrations. This sludge is generally high in silica compounds, chlorides, arsenic, mercury, nickel, and other toxic heavy metals” (UCS) Due to this, those who monitor these heat pumps must carefully monitor the frequency of these toxins in the discharge. “Additional sludge is generated when hydrothermal steam is condensed, causing the dissolved solids to precipitate out.” (UCS) Due to these issues, operators of geothermal heat pumps are often very reluctant to use scrubbers.
The other environmental issue associated with geothermal energy is the issue of land subsidence. This occurs due to the geothermal heat pump removing water from the aquifer in order to provide the needed energy. However, just like the previous issue, land subsidence can be easily prevented by simple means. “Usually the best disposal method is to inject liquid wastes or redissolved solids back into a porous stratum of a geothermal well.” (UCS) By performing this simple task we are able to incredibly lessen and even eliminate the land subsidence caused by geothermal heat pumping. For example, “At Wairakei, New Zealand, where wastes and condensates were injected for many years, the area hasn’t sunk at all since 1958.” (UCS) This shows how land subsidence caused by geothermal energy can be easily diverted by simple means.
One final question mark with geothermal energy is many aren’t aware how much of it is available for our use. “Thousands more megawatts of power than are currently being produced could be developed from already-identified hydrothermal resources.” (GE) This is due to the fact that usable geothermal resources will not be limited to the “shallow” hydrothermal reservoirs that most people think constitutes geothermal energy. In addition, many believe that geothermal energy is restricted to hot underground water sources. However, geothermal energy can be widely collected by deep dry rock that is heated by the magma of the inner earth. “Scientists in the U.S.A., Japan, England, France, Germany and Belgium have experimented with piping water into this deep hot rock to create more hydrothermal resources for use in geothermal power plants.” (GE) This just shows what a valuable and extensive resource geothermal energy really is.
As fossil fuels become more and more obsolete, new forms of energy will need to be explored. The frontrunner of the renewable energy source should be geothermal energy. Geothermal energy should be further explored because; our current energy system is failing rapidly, geothermal energy is an efficient form of energy, and it isn’t as environmentally taxing as other methods of obtaining energy.