Geothermal Energy: The Alternative of the Future

Geothermal Energy: The Alternative of the Future


When the energy crisis hit Americans in the 1970's, people were scrambling to find ways to conserve energy. The crisis brought to attention the very real shortage of fossil fuels. Gas and oil prices skyrocketed, and Americans looked for ways to save energy. They started producing smaller cars, driving less, and turning down their thermostats. Also, they started to examine alternate energy sources, such as solar, geothermal, and biomass. For a while, Americans were making a conscious effort to cut back on the use of fossil fuels. However, when gas and oil prices started to go back down in the early eighties, many of the conservation ideas were forgotten. In the minds of most Americans, the energy crisis had been solved because they could now afford to use fossil fuels again.

Looking into the next century, we can see energy shortage problems starting to resurface. The possibility of another energy crisis is very real; however, this one will be different. It will not be a matter of fossil fuels being too expensive, it will be a matter of fossil fuels no longer being a resource. Our gas-powered cars, factories, and heating systems are using fossil fuels much faster than the dinosaurs are turning to coal. The way things are going now, we won't make it through the next century before running out of our fossil fuels.

The problems with fossil fuels go beyond their rapid depletion. The pollution from burning fossil fuels is really taking a toll on the environmentand the atmosphere. Factories in the United States spend millions of dollars on filtration systems to try and cut down on the amount of harmful emissions, yet the environment just isn't getting better. Converting fossil fuels to energy is a large contributor to the problem. Besides the fact that fossil fuels are ruining our surroundings, their availability is always questionable. Currently, the U.S. buys most of its oil from Middle Eastern countries. What happens if our foreign trade with the Middle East does not hold up? The unstable foreign trade lead to the energy crisis of the 1970's, and it could happen again without much warning. A glimpse of this could be seen during the Desert Storm conflict, when oil prices went up. In a more serious situation, the U.S. is stuck without an energy source.

These are major problems that need to be addressed, before suddenly we are without energy. We are not saying that we need to ban the use of fossil fuels, maybe we need to just start looking seriously into alternate energy sources. The most obvious source right now seems to be solar energy; however, there is another renewable resource that many people might not know about. Geothermal energy is a resource that does not harm the environment, and is not dependent on foreign trade ("Geothermal Heat Increases," 1998). No fuel is burned when the plants are operated. This cuts down on the amount of carbon dioxide and other gases formed during the combustion of fossil fuels, producing one-sixth the amount of carbon dioxide that natural gas plants do, and none of the nitrous oxide or sulfur bearing gases ("Geothermal Energy Technical Site," 1997). Geothermal energy is also easy on the land because there are no mineshafts, tunnels, open pits, waste heaps, or oil spills ("Geothermal Education Office," 1998).

In addition, using geothermal energy would help the foreign trade of both wealthy countries, such as the United States, as well as many third world countries. Geothermal energy would allow the U.S. to become independent from the unstable Middle Eastern trade, because it is literally right in our backyard (Cole, 1998). On the other hand, it helps developing countries grow, because they do not need to depend on other large countries for energy ("Geothermal Education Office," 1998). Ukraine is a prime example of this. There is an energy crisis that is digging a hole in their national economy, and the Ukrainian Government is turning to geothermal energy to fill it in. There are currently nine geothermal plants in operation, and another one is a work in progress. A $2 million payback is estimated upon completion of the tenth plant. Thousands of jobs are being created by these plants, and the amount of money that would otherwise be paid to foreign countries for fossil fuels is astronomical ("GeothermalÖfill energy gap," 1996).

It all sounds like a good idea, but many people are unaware of how it operates. Geothermal energy is available wherever the earth's large oceanic and crystal plates slide apart. This is based on the idea of plate tectonics. The earth is made up of huge plates of rock, floating on molten rock and magma. These plates do not fit together perfectly, and where the plates touch there is buckling and grinding. This movement creates friciton and pressure, allowing ground water within the plates, to come in contact with deep subsurface heat sources, namely magma ("Geothermal Technologies," 1996). Geothermal energy then uses the natural hot water and steam that is produced as a result of the plate collisions to create energy. This usage is called hydrothemal energy ("Geothermal Heat Increases," 1998). There are currently three technologies used to convert hydromthermal fluids to electricity. The first, routes steam created from the collisions of the plates, to large turbines. These turbines consist of a huge cylinder with a blade-rotating engine. When the steam builds up in the turbine, the blade starts to rotate because the steam particles are moving so fast. The turbine in turn drives the generator that creates the electricity. This process replaces the need for fossil fuel boilers used in conventional power plants. ("Geothermal Electricity,"1998).

The second technique simply uses high temperature water (over 200ƒ C). This process is used when the underground source is not hot enough to turn the water to steam. Highly pressured fluid is sprayed from the plates into a tank of lower pressure. This rapid drop in pressure causes some of the fluid to vaporize quickly, or "flash" into steam. Once converted to steam, the turbine is activated to power the generator, as in the first technique. Any left over fluids can be recycled by returning it to the earth to increase the pressure, making this process very efficient. Because water is used in this process, not steam, the amount of friction between the plates does not have to be as great as in the first process ("Geothermal Electricity," 1998).

The last hydrothemal process is the most complicated, because it utilizes fluids that are at a temperature lower than 200ƒ C. This fluid cannot vaporize itself; however, it does produce enough heat to vaporize other liquids. Boiling fluid is pumped from the earth into a tank similar to a double boiler. The inside part of the double boiler contains a secondary fluid with a low boiling point. This secondary fluid will boil and flash into steam to once again drive the turbine and so forth. These plants are generally smaller than say, steam of high temperature facilities making them beneficial to small industries that lack a prime geothermal location where there is a lot of plate activity (Mclarty, 1998).

There are other sources of geothermal energy besides hydrothermal fluid, such as hot dry rock, geopressured brines, magma, and ambient ground heat. Hydrothermal fluid is currently the only source used on a widescale basis; however, hot dry rock is another up and coming method in places where hydrothermal systems are not hot enough to drive turbines. The earth's plates are comprised of layers of rock, that increase in heat until you reach the inner core, estimated at 6,650ƒ C. The current theory is that cold water will be heated if it is pumped into this rock at high pressure. The water is then drawn back to the surface as steam to drive turbines. The higher the temperature, the more efficient the system works. The main problem that geologists are having right now is to make the water hot enough. The pressurized water needs to be pumped six kilometers under the surface, and by needing to go deeper, it is upping the cost of the geothermal plant (Graham-Rowe, 1998).

Cost however, is relative. While the initial costs of exploratory drilling are somewhat expensive, actually building the plants is very cost efficient. Coal and oil shale plants cost $1 billion and $600 million respectively to build, but two hydrothermal plants cost $100 million together (Devine, 1998). Therefore, this is a relatively cheap energy source. Along with lower start-up costs than conventional energy sources, there are other financial benefits associated with geothermal energy. The U.S. government is currently offering financial support to organizations that choose geothermal energy resources over fossil fuels ("College Subtracts EnergyÖ," 1995). In addition, several states are considering weighted cost factors for industries that plan to continue using the environmentally unsafe fossil fuels (Mclarty, 1998). When a new company or corporation is taking bids from electrical companies, some states mandate those energy sources that are potentially harmful to the environment must increase their bid, to ensure the safety of the environment. In doing this, geothermal energy looks even more attractive.

These laws and mandates are not nation wide because geothermal energy is just not logical in some places. The prime locations for geothermal energy use and production are known as hot spots. Hot spots are the places where large oceanic and crystal plates collide and slide apart. This is where geothermal energy is most readily available. Some spots are the Ring of Fire-the islands in the Pacific Ocean-, the South American Andes, Central America, Mexico, the Cascade Range of the U.S. and Canada, the Aleutian range of Alaska, the Kahichatka Peninsula of Russia, Japan, the Philippines, Indonesia, and New Zealand ("Geothermal Education Office," 1998). Currently New Zealand and Indonesia are two of the hottest spots for geothermal energy. Since the 1950's, New Zealand has been using the underground energy to benefit their economy. It has steadily developed for the last 40 years and now has the potential to supply 10% of the country's power needs. Regulations set by the New Zealand government has encouraged expansion of commercial industry. There are many other countries that have the potential for large advancements, including Indonesia. The geothermal reserves in Indonesia equal 16,000 megawatts of electricity per year (Cole, 1998).

To put into perspective the amount of money that 16,000 megawatts of geothermal energy can produce, lets look at the United States. The U.S. is only producing about 2200 megawatts of energy per year, and it accounts for $1 billion of revenue. This takes the place of 30 million barrels of oil that we would otherwise need to import (Mclarity, 1998). If Indonesia has the potential to have 16,000 megawatts of geothermal energy per year; the amount of revenue could be as high as $7.3 billion.

Everything seems to point out that geothermal energy is the resource of the future, so why isn't it used more? First, we must point out that we do not think that the use of fossil fuels should be dropped completely. There are locations where geothermal energy just isn't available or very cost effective; however, we need to start looking at the other places were geothermal energy is possible. People worldwide need to make a conscious effort to use geothermal energy wherever it is possible. Because geothermal energy is a fairly new topic, people are tentative to commit to it for fear that it is just a passing fad that will soon be proven ineffective. In fact, geothermal energy is here to stay, and we need to start taking it seriously, because it will be a very important option in the future. Fossil fuels are rapidly depleting, and geothermal energy is picking up where it is leaving off.

Explore Clarke College's use of geothermal energy

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