Is geothermal renewable or nonrenewable – understand geothermal energy

Is geothermal enegy renewable or inexhaustible?

is geothermal renewable or nonrenewable

Is geothermal renewable or nonrenewable‘ is a query I have come across many times from several people including from students studying energy issues. Most of these people who have this doubt in their minds is probably confused about the meaning of the terms ‘Renewable’ and ‘Nonrenewable’. It is, therefore, imperative to first explain these two terms with reference to the energy sources for better understanding of the real answer to the question – is geothermal renewable or nonrenewable?

What are renewable and nonrenewable resources

Renewable energy is a term that speaks for itself. This refers to energy that is generated from natural processes that are continuously replenished at a faster rate than they are consumed. Examples of renewable energy sources are sunlight, geothermal heat, wind, tides, water, and various forms of biomass. Whereas nonrenewable energy comes from sources that can’t be replenished in a short period of time. Sources of non renewable energy include fossil fuels such as coal, oil, natural gas, and nuclear energy fuel, Uranium. Fossil fuels are thought to have been formed from the buried remains of plants and animals that lived millions of years ago. These resources are consumed by us much faster than nature can create them. Eventually they will be exhausted altogether sooner or later and hence we cannot sustain our reliance on them indefinitely.

Is geothermal renewable or nonrenewable?

Typically, when someone ask me this question  – ‘is geothermal renewable or nonrenewable’, my first response would be – geothermal is indeed a renewable source. But before I go to explain why is geothermal energy a renewable resource I need to explain first what Geothermal energy is.

What is geothermal energy?

Geothermal energy is defined as the energy that emanates from the heat in the core of the earth. ‘Geothermal’ literally means ‘Earth’s heat, which is estimated to be 5,500 degrees centigrade at the Earth’s core – about as hot as the surface of the sun. This energy is sustainable and a clean resource that can be tapped by many countries around the world located in geologically favourable places.

is geothermal renewable or nonrenewable

What is geothermal energy?

The centre of the earth which lies almost 4,000 miles beneath its’ surface is so hot that it is in a molten state. Heat from the earth’s core radiates outwards and heats up the outer layers of rock called the ‘Mantle’. When the rocks in the outermost shell of the earth made of the earth’s crust and upper part of the mantle melts at extremely high temperatures, this molten rock is called ‘Magma’. The temperature of magma usually falls somewhere between 700 and 1300 degrees Celsius. Magma (molten rock) may come quite close to the surface of the earth. When magma comes close to the surface it transfers heat to the ground water found trapped in porous rock or water running along fractured rock surfaces. A usable form of geothermal energy is thus created under the earth’s surface. Some of this super heated water rises back to the surface of the earth where it emerges as hot springs or even geysers and steam vents. Sometimes the hot water becomes trapped below the surface as a geothermal reservoir. By drilling boreholes into these geothermal reservoirs the hot water and steam are piped up which can then be used directly to heat our homes and businesses or to generate electricity. Many countries have developed various methods of tapping into these geothermal energy sources.

Now that it is explained what is geothermal energy it would be easier to answer – is geothermal renewable or nonrenewable.

Why is geothermal energy renewable?

Now that you know what is geothermal energy let me now explain – why is geothermal energy a renewable resource. Geothermal is considered a renewable resource because this is a natural source of energy which is  replenished naturally and is not going to run out even if re-used multiple times. Geothermal energy harnesses energy from Magma, the earth’s molten rock, which continuously produces heat at a constant rate and this heat is not going to exhaust if re-used several times since it is generated from the core of the earth. At any one geothermal field, however, the temperature of the geothermal reservoir or the water levels or pressure in the reservoir may decrease over time as fluids are produced and energy is extracted. However, the volume of water taken out can be re-injected to maintain pressure, making it a sustainable energy source. Oil fields can be depleted, making it a non-renewable form of energy, whereas geothermal heat is not.

Conclusion

Now that it is clear that geothermal is a source of energy that is replenished by nature continuously and is not going to run out eventually, there should not be any confusion in understanding the true answer to the question – is geothermal renewable or nonrenewable.

However, one point needs to be kept in mind that things aren’t always the same as they may seem. In-spite of several advantages of geothermal energy some of its disadvantages also need to be considered while studying the subject issue. At the face value, the energy radiated from the heat in the core of the earth is totally renewable. Nevertheless, it is also true that changes in the underlying structure of the earth’s crust may cause geothermal wells to go dry and stop producing heat. This disadvantage of the energy source is something that we have absolutely no control over. A productive geothermal well that is working perfectly today may be of no use 10 or 20 years from now. Over time, it is, therefore, commonly necessary to drill additional wells in order to maintain energy production as temperatures and/or reservoir fluid pressures decline.

 

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