Skip to content
A geothermal power plant producing clean geothermal energy.

Geothermal Energy Pros & Cons

In this article, we will be discussing a number of geothermal energy pros and cons.

Scientists have estimated that the temperature of the earth’s core is somewhere around 6000 degrees Celsius (about 10,800 degrees Fahrenheit.) This massive amount of geothermal energy heats rocks and reservoirs deep beneath our feet. We can harness these resources in order to generate electricity. With this process comes a number of advantages and disadvantages which you can see below.

The Pros

Renewable and Sustainable

Geothermal energy is both renewable and sustainable. This means that it will never run out – unlike non-renewable energy sources (such as coal, oil, and gas.) For as long as the earth supports life, geothermal energy will exist. Because of this, geothermal energy has an advantage over non-renewable alternatives.

Environmentally Friendly

Geothermal energy is an environmentally friendly energy source. When used to generate power, it has a much lower impact on the environment than fossil fuel alternatives.

Constant Supply

Unlike most other renewable energy sources, geothermal energy can provide a constant supply of electricity. Solar panels can only produce electricity during the day and wind turbines only produce power when there is enough wind. The advantage of a constant electricity supply makes Geothermal energy far more predictable than its rivals.

Small Footprint

Geothermal power plants have a smaller footprint than their coal, oil, and gas equivalents. Although they will reach far down beneath the earth’s surface, their land footprint will be small.

Cost-Effective

We can use geothermal energy to provide a source of cost-effective electricity. Power generated from geothermal energy is one of the cheapest power sources available today.

Low Maintenance

Geothermal installations are low maintenance when compared to traditional power plants. As a result of this, they are reliable and cheap to operate.

Low Noise

Generating electricity from geothermal energy produces little noise. Once the installation is in place, the main source of noise comes from fans contained in its cooling systems. Engineers often install dampening materials in generator houses to further minimize noise pollution.

Reduces Fossil Fuel Dependency

When we use geothermal energy, we cut our dependency on fossil fuel alternatives. This is great for the environment and means we are less vulnerable to supply and demand issues associated with fossil fuels.

Increases Energy Security

Geothermal energy can help to increase energy security. By using local geothermal resources, we reduce the need to source supplies from other countries. As a result of this, we are less reliant on external influences, which in turn helps to increase our energy security.

Job Creation

The creation of a global geothermal energy industry has helped to create jobs all over the world. In fact, the geothermal industry supported 35,000 American jobs between 2012-2013 (both direct and indirectly.) This figure is based on a 2014 report from the International Renewable Energy Agency (IRENA.)

Huge Potential

Geothermal power has huge potential in some parts of the world. A recent study by the Geothermal Energy Association (GEA) estimates that just 6.5% of this potential has been tapped so far. In fact, global geothermal energy potential could be in the range of 35 gigawatts (GW) to 2 terawatts (TW.) This figure has been estimated by the Intergovernmental Panel on Climate Change (IPCC).

The Cons

Geographical Limitations

Geothermal energy is arguably the most location-specific energy source known to man. Geothermal activity is at its greatest along tectonic fault lines within the earth’s crust. It is in these locations where geothermal power has the biggest potential.

The disadvantage of this is that very few countries are able to tap into geothermal resources. The United States, Iceland, Kenya, Indonesia, Philippines, and Mexico are the main producers of geothermal power.

Large Investment Needed

Geothermal power plants are very expensive and often require significant investment. Although they have low running costs, their initial construction cost can be far higher than coal, oil, and gas power plants. A large part of this cost concerns the exploration and drilling for geothermal energy resources. Traditional power stations don’t require exploration and/or drilling.

Environmental Impacts

A key disadvantage of geothermal energy is the impact it can have on the environment.

Below the earth’s surface lies an abundance of gases that are harmful to the environment and our atmosphere. During the production of geothermal power, these gases can be released into the atmosphere. The gases in question include the following, some of which can contribute to global warming:

  • Hydrogen Sulfide (H2S)
  • Carbon Dioxide (CO2)
  • Ammonia (NH3)
  • Methane (CH4)
  • Boron (B)

The process of producing electricity from geothermal energy can also affect water quality. Chemicals used at some geothermal power plants occasionally leak and pollute the water table. Although technology exists for the safe use of these chemicals, there is always the potential for leakage to occur.

Whilst there are numerous environmental factors to consider, geothermal energy is still one of the most environmentally friendly energy sources available.

Sustainability Concerns

Human activity can affect the sustainability of geothermal energy. Studies show that without careful management of geothermal reservoirs, they can become depleted. In such cases, geothermal power plants would be rendered useless until the reservoir recovers.

Geothermal technology advancements are helping to make sustainability concerns less of an issue. Now, after we have made use of geothermal fluids, we can inject them back to their source. As a result of this, there is less chance of a geothermal well becoming depleted.

Seismic Instability

Geothermal installations have been known to cause earth tremors in various parts of the world. Although often minor, this seismic activity can lead to building damage, injuries, and death.

In 2006, a geothermal exploration project in Basel, Switzerland was blamed for a series of earthquakes. Some of these quakes measured up to 3.4 on the Richter scale. A further study in 2011 found a strong correlation between geothermal exploration and seismic activity. This study focused on the area around the Salton Sea geothermal field in the United States.