Does Geothermal Energy Cause Pollution?

Updated on January 26, 2023

Geothermal energy can cause pollution if not managed properly but this is minimal. While small quantities of toxic gasses are sometimes released, greenhouse gases such as carbon dioxide (CO2) are the main emissions. Gaseous emissions are minimized by injecting geothermal fluid back into underground reservoirs to maintain equilibrium and sustain renewable resources.

Is geothermal energy renewable?

First of all, we need to agree on a workable definition of ‘renewable’. Most things are renewable given time. Even coal, gas and oil will replenish themselves over a million years or so. Unfortunately, we will all be long gone!

What we really mean is ‘renewable faster than we can use it’. In the case of fossil fuels for energy this is definitely not the case; it will all be gone in 40 to 50 years.

Why is geothermal energy considered renewable energy?

Geothermal is truly renewable, as it is derived from the heat generated by the Earth itself. The heat generated deep underground permeates throughout the rock strata, and the upper layers of relatively lower temperature can be extracted and converted into energy we can use.

The heat deep underground will always be there as long as the earth exists, long after humanity is gone! The enormous pressure inside the earth due to gravity generates very high temperatures in the iron core and gradually reduces the nearer you get to the surface.

Geothermal advantages and disadvantages

All energy sources have benefits and drawbacks but for geothermal the pros outweigh the cons, I feel. Nothing is perfect, but geothermal is pretty close, if we could make drilling and extraction more cost-effective.

Once a plant is up and running, the maintenance costs are low and it can last for 50 years, or so, while paying for itself within 10 years. The table below lists geothermal pros and cons, including the ecological impacts of mild pollution and its carbon footprint:

Table – Does geothermal pollute? Geothermal energy environmental impact

Geothermal Advantages (Pros/benefits)

Geothermal Disdavantages (drawbacks/cons)

Low running costs once established

High installation & surveying costs (investment)

Low carbon footprint (38 gms CO2/kWh)

Machines needed to extract and convert heat

Low ecological impact

Above machines made by fossil fuel energy

Renewable and sustainable

Can cause minor earthquakes

Generate electricity cleanly

Location dependent to some extent

Heat buildings directly

Deep drilling needed for high temperature plant (higher temp. = higher efficiency)

Flexible agricultural use

Possible release of greenhouse and toxic gases

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Does geothermal energy cause global warming?

The theory states that global warming is due to the release of so-called greenhouse gases since civilization became industrialized in the 1700s. However, this is a theory that is not proven.

Although main-stream media push the agenda, at least 50% of earth-based scientists disagree. Climate cycles going back thousands of years show that the panet’s temperature swings up and down according to many factors, including the sun.

Renewable and non-renewable energy recourses may or may not contribute to global warming.

Does geothermal energy produce carbon dioxide?

Carbon dioxide can be released for the rock strata during drilling for, and operating, a geothermal plant. Compared to other plants using relatively clean fuels, such as gas, these emissions are very low – about 17% og a similar plant using natural gas.

As a comparison, geothermal produces about 38 gms CO2/kWh. The table below compares this with conventional and other renewable resource options:

Table – CO2 emissions – power plants compared

Generating Plant – energy used

CO2 Emmissions


38 gms CO2/kWh


50 gms CO2/kWh (includes solar panel manufacture)

Wind turbines

11 gms CO2/kWh


27 gms CO2/kWh


4 gms CO2/kWh


915 gms CO2/kWh


190 gms CO2/kWh

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Does geothermal energy produce greenhouse gases apart from CO2?

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Other greenhouse gases include methane (CH4) but these emissions are neglible. It’s worth noting that that methane is a much more powerful greenhouse gas than CO2, up to 100 times more!

What type of pollution does geothermal energy cause?

Any pollution is low, due to the fact that plants do not burn fossil fuels – the raw energy comes from the heat locked up in rock or water reservoirs deep inside the earth. Of course, some energy derived from non renewable resources is used in operating a plant, but the amount compared to the overall energy recovered is very small.

Gases can be released, such as CO, which is a greenhouse gas. CO2 isn’t really a pollutant, but other trace gases released are, like sulfur dioxide and nitrous oxide. They are released as a by-product of opening up deep wells to the atmosphere and they are minimal.

One type of plant fractures rocks so that water can be forced through and return to the surface carrying heat from the rocks. In this case pollutants such as heavy metals can be brought back to the surface and possible contaminate fresh water supplies, affecting the health of himans and wild-life alike.

What are the economic impacts of geothermal energy?

Economic impacts center around the necessity for reducing our reliance on fossil fuels which emit greenhouse gases into the planet’s atmosphere.

Estimates vary, but it seems that in the not-too-distant future billions of dollars will be needed each year to counter the effects of rising global temperatures and rising sea levels.

For the home owner, using geothermal in the form of a heat pump for heating a house reduces monthly costs by up to 70%, which represents a considerable economic benefit. Heat pumps can pay for themselves within 10 years and generally output 4 times more heat energy than they use in electrical energy.

How does geothermal energy affect humans?

Compared to traditional forms of energy production there seems to be minimal effect on human beings, although this is still being studies as the use of geothermal is not that widespread.

Can geothermal cause health problems?

Many communities report an odor from geothermal plants but how this affects human health is not conclusive yet. Benzene smells pretty strong even in small concentrations but it isn’t harmful at that level.

It’s never a good idea to have any chemical pollutants in the natural world where things grow and geothermal plants must be rigorously managed to make sure this is controlled.

Effects of geothermal power on human health PDF

Can geothermal cause health problems?

Does geothermal energy cause global warming?

How does geothermal energy affect the environment?

There are no major effects and the obvious question is ‘What is the effect on humans?

There are some positive environmental impacts, mostly due to the fact that this tyope of energy means less fossil fuels are used, which we know cause global warming.

While there are some disadvantages, these are relatively few in number. At the very minimum, the economic impacts of geothermal energy, like hydropower, are good for mankind as a whole – by spending less on non renewable resources that inevitably cause pollution.

Some disadvantages of geothermal energy

All energy resources have disadvantages but geothermal has less than many others. The first thing to look for is the effect on the environment. After all, it’s no use having a fantastic source of energy if it’s slowly killing us!

Once we establish levels  (or non-levels) of pollution that we will tolerate, the second thing to consider is the cost – can we afford to extract the energy?

The biggest disadvantage of extracting heat from inside the earth is the big cost of drilling and setting up a power plant, whose costs vary according to the type of plant. Running costs are relatively low, so it’s the initial cost that gives us problems.

Another disadvantage is that you can’t just pick a spot and drill. Of course, the heat underground is everywhere, but in some places it’s found less deep than others. This means that economic heat extraction is to some extent location dependent.

Is geothermal energy safe?

Geothermal energy is very safe. Although there has been some concern about earthquakes due to destabilized rock strata, there are no recorded instances of people being harmed by such an occurrence.

All plants are subject to strict regulations concerning safe operation and emissions of toxic substances likely to harm living creatures.

Is geothermal energy expensive?

The biggest expense of geothermal power plant set up is the installation cost, which can run into a couple of million dollars for a 1MW generating station. However, once built, all types of plants have a low running and maintenance cost.

On a smaller scale, individual home-heating using heat pumps is still relatively expensive at between $15000 to $30000 depending on the size of the home, but as with industrial plants, runningcosts are low with neglable maintenance costs.

Positive environmental impacts of geothermal energy

Positive environmental impacts tend to be of a secondary nature. That is, geothermal helps the environment by replacing technology that harms it, such as coal and gas.

Using fossil fuels for the last 200 years has placed an enormous negative load on the earth’s atmosphere and general ecosphere. Pollution is rife, destroying wildlife and plants everywhere. We are even destroying our forests at the rate of a football field every second!

Geothermal energy could stop this destruction, but it needs to be implemented much faster than at present. The installation costs are the problem, but the costs of dealing with the effects of global warming must also be taken into account to estimate the true cost to our environment.

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