Geothermal energy is the energy that is stored as heat under the solid surface of earth. Though the energy released from a volcanic cannot be controlled and collected, scientists have formulated methods to tap this energy. This heat can be collected from rare places from the earth’s crust in the form of steam or hot water. Pipes carry the hot water to a plant, where some steam is allowed to “flash,” or separate from the water. That steam then turns a turbine – generator to make electricity.
Let’s take a look at the recent historical development. It can be said that geothermal energy was first used in Italy in 1903 to produce one of the essential needs of humans, which is electricity (Energy Kid’s page, 2006). After the Second World War, several countries considered geothermal energy potentials, as it is characterized by its economic nature competitive with other forms of energy. Besides, geothermal energy is a unique form of energy compared to other energy sources, as it need not have to be imported. For example, many countries import oil as their primary source of energy.
An increasing trend has been observed over the years in the case of the utilization of geothermal energy in developing countries. According to Dickson and Fanelli (1988), between 1975 and 1979, the geothermal electric capacity installed in the developing countries increased from 75 to 462 MWe; in the next five-year period (by the end of 1984), this figure had risen to 1495 MWe. The rate of increase during these two periods is 500% and 223%, respectively. Further, an increase of almost 150% took place in the next sixteen years, i.e., from 1984 to 2000. There is a great significance of geothermal power, especially in the energy balance of some areas. For instance, in 2001, the electric energy generated from geothermal resources represented 27% of the total electricity generated in the Philippines, 12.4% in Kenya, 11.4% in Costa Rica, and 4.3% in El Salvador (Dickson and Fanelli, 2004).
Currently, geothermal energy is utilized in many ways, including thermal waters piped directly from the ground to support greenhouses, fish farms, and municipal heating systems. Geothermal energy is widely considered the ideal means for heating and air conditioning schools, homes, and workplaces because geothermal heat pumps can be installed almost anywhere. Recovering Earth’s heat at high temperatures and rates is a challenge of daunting complexity in the absence of a natural hydrothermal system. Even so, the potential resource base is so huge that researchers in the United States, Japan, and Europe are determined to build up the means. These research programs show enormous potential to increase the accessibility of geothermal energy for future generations (Hulen and Wright, 2001).
In the USA alone, at the end of 2004, there were 43 power plants producing electricity from geothermal energy. However, one of the major disadvantages with this energy is that it is “site specific,” which means to say that it is only possible to extract geothermal energy in a few places under unique geologic conditions (Energy Kid’s page, 2006). The Earth’s thermal energy is enormous, but only a part of it could be utilized by humanity. If we look at the advantages of using geothermal energy, the direct use of this resource is a proven, economic, and clean energy option. In other words, geothermal energy is an energy source that saves money and reduces pollution (Office of Geothermal Technologies, 1998). If geothermal energy is exploited systematically, it could assume an essential role in the energy balance for a few countries. Under certain circumstances, even small-scale geothermal resources are competent to solve several local or regional problems faced by millions and can contribute to increasing the standard of living.