The concept of renewable energy and of “renewableness” in general, came to fame in the 1970s, in an attempt to offset the development of nuclear energy and fossil fuel. The most common definition is the energy source that can be quickly restored back naturally, and the process is ongoing. With this definition, nuclear and fossil fuels are not included in it.
Geothermal energy comes from radioactive decay in the center of the Earth, making the Earth heat from within, and from the hot summer sun that heats the surface of the earth up. There are three ways of utilization of geothermal energy:
- As the power plant and is used in the form of electricity
- Utilized as a heat source directly using the pipe into the ground
- As the heat pump is pumped directly from the ground
The term ‘geothermal’ is used to name heat energy derived from the earth. Geothermal electricity is generated by utilizing the steam coming out of the pipe put into the ground as a result of heating water infiltration around the geothermal wells. The vapor is then used directly to spin turbines or to heat the heat exchanger to generate pressure, then used to turn turbines and generate electricity through a generator.
Geothermal energy from the core of the Earth is closer to the surface in some areas than others. Where steam or underground water can be harnessed and brought to the surface it can be used to generate electricity. Such geothermal power sources exist in some geologically unstable parts of the world such as Iceland, New Zealand, the United States, the Philippines and Italy. The two most prominent areas for this in the United States are in Yellowstone basin and in northern California. Iceland produced 170 MW geothermal power and heated 86% of all houses in the year 2000 through geothermal energy. Some 8,000 MW of operational capacity total.
Geothermal heat from the Earth’s surface can be used in most of the world directly to heat and cool the building. Crust temperature a few feet below the surface is buffered to a constant 7-14°C (45-58°F), so that the fluid can be pre-heated or pre-cooled in underground pipes, providing free cooling in summer and, via a heat pump, heating winter. Another direct use is in agriculture (greenhouses), and aquaculture industries.
Although geothermal sites are capable of providing heat for many decades, eventually specific locations quiet. Some interpret this as meaning a specific geothermal location can undergo depletion. Others see such an interpretation as inaccurate use of the world because the overall thinning supply of geothermal energy in the earth, and its source, remains almost constant. The truth is that geothermal energy depends on the local geological instability, which, by definition, is unpredictable, and may be unstable.
Now Geothermal energy consumption does not in any way threaten or diminish the quality of life, consequently, it is considered a renewable energy source.