As society becomes more and more interested in the use of clean and renewable energy sources, convenient and affordable options are starting to surface. Clean, renewable sources come in many forms, through solar power, wind power, and even geothermal power.
Geothermal power is a natural source that initially came from the origination of the earth. There are other contributing factors to the inner earth’s power, such as the shifting of tectonic plates, the decay of radioactive minerals and elements, as well as the energy generated from solar rays continuously striking the earth’s crust.
It is important to differentiate between geothermal energy and thermal energy. Geothermal energy is power that is generated within the earth, while thermal energy is generated through the heating and acceleration of molecules.
Geothermal energy can be harnessed in many ways. The most popular are geothermal heat pumps, geothermal hot water, and geothermal hot dry rock. All of these things can be harnessed with the use of geothermal plants. The plants themselves, though, are not necessarily cost efficient yet. The plants themselves emit some pollution. Any drilling that is done can release noxious gases such as carbon dioxide and greenhouse gases. This is a contributing factor to the diminishing atmosphere as well as to acid rains.
While geothermal energy is not 100 percent clean, it is 100 percent renewable. The release of some greenhouse gases is still less than those emitted through the burning of fossil fuels, which are not renewable and extremely harsh on the environment. Many geothermal power plants do use extra processes to minimize the emission of pollutants. It has also been theorized that any toxic fluids emitted during the process of harnessing geothermal energy can be injected back into the earth’s core, so they will not come in contact with the atmosphere.
Geothermal hot water (hot springs are considered to be geothermal hot water) can be found underground and can be used many ways. It can be pumped directly into an application for hot water or it can be used to heat buildings, grow greenhouse plants, fish farming, and pasteurizing. For instance, water issued from hot springs is heated by the geothermal heat from the interior of the earth. The temperature of the earth’s rocks increase with depth (known as a geothermal gradient.) If water reaches into the crust it comes in contact with these very hot rocks. The water from hot springs in non-volcanic areas is heated in this manner.
Geothermal hot dry rock can also be used to generate electricity. Cracks and pores in the rock release geothermal energy which can be captured. If the rate of geothermal energy released is not sufficient for power generation, high-pressure cold water is pumped into the rock. The water captures the heat of the rock until it is forced out of the ground in the form of hot water. The water is then converted into electricity with either a steam turbine or a binary power plant system.
While geothermal energy itself is renewable, geothermal sites are not necessarily. An overworked site, or one with an excessively large energy plant, can quickly be depleted. Geothermal power sites also need to be actively managed to minimize the release of greenhouse gases and toxic elements so as to limit the impact to the surrounding environment.