Is Geothermal Energy Renewable Or Nonrenewable? 7 Facts

Based on extinction of sources of energy, we derive energy as renewable and nonrenewable. Let us discuss on geothermal energy is renewable or non renewable.

Geothermal energy is renewable. An energy source is considered as renewable when they can be replenished and sustain over billions of years. Geothermal energy is the heat emitted from the earth’s core caused by the radioactive decay of minerals. This heat replenish constantly over human timescale.

Geothermal energy comes from natural resources and continuous conduction of internal heat driven from the center to exterior surface. Let us discuss how geothermal energy is renewable in this post.

How geothermal energy is renewable?

Renewable energy is referred as inexhaustible with limited amount of flow rate per time. Let us demonstrate geothermal energy as renewable.

Geothermal energy is renewable by its inexhaustible resources. The earth’s core exerts high pressure causing some rocks to melt and emitting high temperature at the core. The temperature transferred to the surface available for 24 hours a day and 365 days a year making geothermal energy renewable.

At the inner core of the earth the heat content is about 1031 joules which is very much greater than any projected heat at the surface. The heat emitted by geothermal resource is much greater than the human consumption of heat extracted from inner core through geothermal reservoir. 

Why geothermal energy is renewable?

During the formation of planet the geothermal energy generates. Let us reason out why geothermal energy is renewable.

Geothermal energy is renewable because during the formation of planet, large amount of heat is generated and stored in the inner core. This heat is retained for so long and regeneration of heat is take place continuously by radioactive decay at the core even though some amount of heat lost.

When geothermal energy is nonrenewable and how?

Any form of energy which cannot be replenished or run out quickly over few years is called non renewable energy. Let us look at when geothermal energy is nonrenewable.

Geothermal energy is nonrenewable when the steam pressure required to run the turbine ran out. Generation of power utilizing only one geothermal reservoir is difficult because heat  from the earth core exhaust over few years at that location. Hence, geothermal energy is nonrenewable.

The heat radiated from the earth is utilized for the power generation by converting the heat into steam by injecting water to the hot rocks. When sufficient heat is extracted, the rocks become cooler and power production becomes difficult. Therefore, another suitable location must be find to harvest geothermal energy.

Geothermal Power plant
Image credits: Wikimedia commons

How long can geothermal energy last?

The renewable energy resource does not deplete over a period of time and are most abundant. Let us discus about life time of geothermal energy.

Earth’s geothermal energy is emitting heat continuously about 4.5billion years and it will continue to emit heat for billions of years. The geothermal energy last when radioactive decay completely dies out in the core. A low end estimation of existence of geothermal energy is about 17billion years.

A study states that lifetime of geothermal energy also depends on the lifetime of sun. If the sun becomes red dwarf, the earth is likely to be frozen causing exhaust of geothermal energy.

Advantages of geothermal energy

The geothermal energy is renewable source which is much advantageous for human convenience. Let us list out major advantages of geothermal energy.

  • Carbon footprint of geothermal thermal energy is low, so it is environment friendly.
  • Geothermal energy reservoir has high potential to generate maximum energy than consumption.
  • Geothermal energy has high reliability. It does not fluctuate and output is accurate.
  • No fuel is required to harvest in geothermal energy.

The geothermal energy uses heating and cooling techniques, so the reservoir acts as sink and source of heat. The temperature difference from ground and surface enhances electricity generation which is major advantage of geothermal energy.

Disadvantages of geothermal energy

Though renewable energy is natural, it has disadvantage due to low efficiency and expensive maintenance. Let us give a list of some disadvantages of geothermal energy.

  • Geothermal energy resource is location specific so accessibility of location becomes hard.
  • Causes environmental side effect due to release of some gases while digging.
  • Geothermal energy stored in earth causes natural calamities such as earthquake.
  • Geothermal energy is an expensive energy resource.

The maintenance of geothermal reservoir is difficult because it deplete much faster than other energy resource and proper maintenance is required for efficient working of turbine. It is also a major disadvantage of geothermal energy.

Does geothermal energy cause pollution?

Most of renewable energy is often referred as clean energy or green energy which means pollution free. Let us see whether the geothermal energy causes pollution or not.

Geothermal energy can cause pollution if the power plants are not maintained properly. Sometimes while extracting heat, some green house gases like carbon dioxide or sulfur dioxide liberated. However, the release of these gases is in very small quantity but they are sufficient to cause pollution.

Direct methodology and application to utilize geothermal energy such as heat pumps has no negative effect on environment. The underground reservoir with geothermal fluid i.e., mixture of hot water and steam consisting of chemical contaminant like mercury is to reduce the emission of greenhouse gases.


Let us wrap this post by stating that geothermal energy radiates heat to the surface of the earth and it is continuous process. The geothermal energy causes rocks to melt and this hot molten rock is called magma. The geothermal energy will remain in the core until the earth exists.

Keerthi Murthi

I am Keerthi K Murthy, I have completed post graduation in Physics, with the specialization in the field of solid state physics. I have always consider physics as a fundamental subject which is connected to our daily life. Being a science student I enjoy exploring new things in physics. As a writer my goal is to reach the readers with the simplified manner through my articles. Reach me –

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