The Pros and Cons of Geothermal Energy

It’s fair to say one of the biggest stories of the century thus far is the quest to come up with greener, more eco-friendly, and sustainable fuel sources. It is a story which is only going to receive more attention and grow larger in importance as the ecological and economic consequences of fossil fuels become clearer. Fossil fuels are outdated and damaging climates at a dangerously fast pace, while the race to supplant them with something cleaner has spurred on both private industry and government, as well as the scientific world, to try to find a better solution. One proposed alternative is geothermal energy. What is geothermal energy, what are the pros and cons at this stage of its development, how does it fare when compared with fossil fuels, and where do we go from here?

What is Geothermal Energy?

As the name implies, geothermal energy refers to types of energy that are generated via thermal sources within the earth. Geothermal energy as we know it first arose in Italy during the early 20th century. Meanwhile, according to the International Renewable Energy Agency, geothermal energy has grown in terms of global usage over the course of the past decade, with geothermal wells, dug miles deep into the Earth, allowing access to steam and reservoirs of hot water that can be used to generate electricity.

Advantages of Using Geothermal Energy

Geothermal energy has been touted as a viable energy source for many of the distinct advantages it offers. 


One of the biggest issues with fossil fuels is that they take millions of years to form and are, thus, essentially, nonrenewable for human usage. By contrast, the Earth continuously produces geothermal energy, making this type of energy a reliable and viable source in the long term. As long as there are reservoirs of hot water and other sources of geothermal heat that can be accessed, geothermal energy will be available as a renewable alternative. That also goes a long way to solidifying geothermal energy’s reputation for sustainability. With sustainable energy as hot a commodity as cleaner, greener energy sources, the fact that geothermal energy can count as both is a substantial argument in its favor.


A criticism of wind and solar energy is that its reliability can fluctuate according to the weather. This is not a problem with geothermal energy, which can be accessed at any time, with geothermal reliability not subject to sunny or windy forecasts. Environmental conditions under the Earth’s crust are considerably less volatile than those above it, and thus, geothermal can provide constant, reliable natural energy, regardless of conditions that might affect the productivity of other sources.


What constitutes “eco-friendliness” is a more complex question than one might expect at first, and there are certainly environmental criticisms of geothermal energy. That said, it is indeed fair to say that, compared with fossil fuels, geothermal energy is a far more eco-friendly option. This is due in part to the fact that it produces a far smaller carbon footprint. The emissions of a geothermal plant, according to the United States Energy Information Administration, may even be as much as 99 percent lower than a fossil fuel plant of the same size (EIA, 2019).

On-Site Production

Another deviation from plants powered by coal and fossil fuels is the fact that geothermal energy is typically generated near the production plant itself. This reduces the cost of processing and transportation necessary with other fuel sources, reducing the overall cost of geothermal energy and making it more economically friendly than fossil fuels.

Benefits for Homeowners

Geothermal can be beneficial for homeowners, due in part to its lower production costs. Additionally, geothermal heating has a much higher efficiency rate than fossil fuel-based alternatives, and recent years have shown a trend toward geothermal heating in homes.

A Burgeoning Industry

One of the downsides of the fossil fuel industry, from an economic standpoint, is that it has hit a wall in terms of expansion. It is hard to imagine the industry growing any larger than it is at present. Between anxieties over “peak oil” and of the ecological harm that oil and carbon emissions have on our environment as part of the broader climate change issue, the oil industry’s best days are very possibly behind it. By contrast, it’s easy to imagine the much rosier outlook that industries tied to greener energies might enjoy in the near future, with greater potential to follow.

Drawbacks of Geothermal Energy

As with any technology, the use of geothermal energy still faces several drawbacks, despite the significant advantages of pursuing geothermal.

Environmental Issues

While most consider geothermal energy to be a more eco-friendly option compared to fossil fuels, that does not mean it’s free of its own environmental issues. At present, geothermal plants can sometimes release harmful chemicals, such as sulfur dioxide, as well as trace amounts of heavy metals like silica, mercury, arsenic, and boron. The digging process to create geothermal areas can also produce greenhouse gasses. That said, while this isn’t an idle concern, the amount of heavy metals and greenhouse gasses produced by current geothermal processes are far less damaging on the whole than fossil fuels, given the latter’s production of greenhouse gasses.

Upfront Costs

While it is fair to say that geothermal heating may save homeowners significant amounts of money in the long run, in the short-term, it can be costly to set up. Homeowners must invest in specialized equipment, which can be costly. The same holds true for initial investments in geothermal power projects, which can cost millions of dollars to set up.

Zone Specific Technology

With geothermal energy dependent on phenomena such as subterranean geysers and hot water to work, it is largely location-specific and, because of this, is not a viable alternative everywhere. However, this may also be said of traditional fossil fuels, since it is only certain regions that are rich enough in oil to spur drilling there.

Tectonic Action

While the type and degree of digging at present does not pose any serious risk of causing what would be considered serious earthquakes, digging deeply enough beneath the Earth’s surface to access geothermal energy does carry with it the risk of upsetting tectonic plates and causing minor tremors. 


In theory, it would be possible to use up the supply of reservoirs and geysers faster than they could be replenished. In practice, however, this is highly unlikely. Given the foreknowledge of this possibility, it’s also a potential conflict that could be easily managed and avoided. Geothermal’s possible sustainability issues register much lower compared to fossil fuels, though it could be argued that geothermal energy generation is not free of problems in this regard.

Comparing the Environmental Effects of Geothermal Energy Versus Fossil Fuels

While it is by no means without flaws, by every conceivable metric, geothermal energy compares favorably against traditional fossil fuels in terms of the impact each has on the environment. Oil and coal reserves are not sustainable at present, while the damage done to the environment in acquiring them presents an additional sustainability concern. Even if greater reserves of oil and coal were to be discovered and limited supplies themselves were no longer a concern, the short and long-term damage that using fossil fuels does to the environment would still present a threat to general sustainability. Given the rate at which sea levels and temperatures are rising, putting low-lying cities around the world at risk and already causing climate change on a global scale, oil and coal cannot continue to be used in the manner they are now without severe risk of further and irreparable global environmental harm. A switch to a more sustainable source of energy has been the focus of numerous global summits in recent years, and sustainability is one of the selling points of geothermal energy. While the process at present is not without some degree of CO2 emissions, at present, this does not pose the same kind of overwhelming threat to the environment as do fossil fuels. Moreover, the use of geothermal energy does not inherently release the CO2 and greenhouse gasses that fossil fuels do. Unlike oil and coal, the energy source itself is “clean,” and it is simply the methodology of extraction and production that could use refinement.

By contrast, so-called clean coal is widely regarded as a myth, and its negative impacts on the environment along with oil are well-documented (Conniff, 2008). Though the oil and coal industries have disputed this fact, the consensus of the global scientific community is that these industries negatively impact the environment and have contributed to the current climate crisis. Geothermal energy, by comparison, is less objectively harmful to the environment than fossil fuels and other traditional forms of energy.

Economic Indications of Geothermal Energy Versus Fossil Fuels 

Though geothermal energy enjoys many advantages over fossil fuels in terms of short and long-term environmental friendliness, the question becomes far murkier when considered in relation to costs, particularly those ranging beyond the initial costs in relation to setting up geothermal plants. A major cost issue of adopting further geothermal plants in the United States is the fact that 70 to 80 percent of the estimated geothermal national reserves are still underground, yet to be undiscovered (Mims, 2009). On one hand, this fact contributes to the sentiment that we have – literally and figuratively – only “scratched the surface” when it comes to geothermal energy’s potential. A race to uncover some of those still-hidden sources could lead one to draw comparisons to the rush to establish oil fields more than a century ago that prompted extensive growth and development – though, this time, with the ultimate result the establishment of a cleaner energy source than oil. However, funding such a revolution, in terms of technology and equipment, could still be quite costly.

Even so, recent years have seen the hourly cost of producing energy via geothermal and other green measures fall in relation to oil and coal. The fossil fuel industries used to be far less expensive than these greener alternatives, which was one reason for their sustained economic preference. This is no longer the case, with green energies like geothermal, as well as wind and solar, becoming more affordable while taxes are levied against oil and coal producers. As of 2019, hydro electric fuel is now the most affordable form of renewable energy, with an average cost of $0.05 per kilowatt hour (Dudley, 2019). Geothermal energy, meanwhile, is only slightly more expensive at $0.10 per kilowatt hour, with wind energy sitting at $0.13 per kilowatt hour.

For comparison’s sake, oil and gas plants usually range somewhere between $0.05 to $0.15 per hour. With the best eco-friendly options now rivaling oil plants and even the costlier green options set to decrease over time while not being faced with the same taxes and other growing headwinds as fossil fuels, green energy is already shaping up to be a better long-term financial bet. The biggest financial competition geothermal energy may see going forward, therefore, isn’t necessarily the fossil fuel industry, but rather other forms of green energy. As the race to develop the best alternative to fossil fuels continues, the efficiency levels of these energies have been on the rise, while their cost per kilowatt has plummeted. This, just as much as improved eco-friendly generation methods, can help determine which is the ultimate successor to coal and oil.

Geothermal energy is already being used as a viable replacement for fossil fuels elsewhere in the world. For example, Iceland already uses geothermal energy for 25 percent of its total electricity usage, while in 2014, indigenous renewable resources accounted for 85 percent of the nation’s total primary energy usage, 66 percent of which were geothermal resources (Orkustofnun, 2020). While Iceland enjoys fortuitous geography and natural geothermal reserves, its overall figures relating to not just geothermal energy, but green energy as a whole, demonstrate that embracing eco-friendly, forward-looking energy policies can work if given the chance. Given the importance of finding more environmentally-friendly energy sources, other nations may do well to consider a similar strategy. As the climate and energy crises worsen and the capabilities of green technologies improve, the impetus to give geothermal and other eco-friendly energy sources more serious consideration will likely only increase with time.


Conniff, R. (2008). “The Myth of Clean Coal.” Yale School of Forestry and Environmental Studies.

Dudley, D. (2019). “Renewable Energy Costs Take Another Tumble, Making Fossil Fuels Look More Expensive Than Ever.” Forbes.

EIA. (2019). “Geothermal Energy and the Environment.” U.S. Energy Information Administration. 

Mims, C. (2009). “Can Geothermal Power Compete with Coal on Price?” Scientific American.

Orkustofnun. (2020). “Geothermal.” National Energy Authority of Iceland.

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