What Are the Pros and Cons of Geothermal Energy?

Geothermal energy is a form of renewable energy that uses the constant temperatures below Earth's surface to generate power and directly heat and cool spaces. It's been around since the early 1900s and represents an enormous opportunity to accelerate the United States’ clean energy growth.

So, why does only 0.4% of the country’s total energy generation come from geothermal energy sources? To understand its potential and why it hasn’t been tapped yet, you first need to know the pros and cons of geothermal energy. 

In this guide, we’ll explain what geothermal energy is, how it can benefit us, the drawbacks associated with its adoption, and how you can take advantage of this energy source in your own home.

What are the pros and cons of geothermal energy?

What is geothermal energy?

In the simplest terms, geothermal energy is energy that comes from the ground in the form of heat. While the temperature at ground level fluctuates widely, temperatures around 40 feet below the surface remain relatively constant. Geothermal energy makes use of that constant heat level as a renewable resource.

There are two primary ways we can use the heat from the ground: 

• Direct use for space heating

• Using geothermal heat to produce steam that spins turbines to generate electricity, much like a traditional power plant. 

In a geothermal power plant, drilling beneath the earth’s surface exposes heat that can be used to create steam that then spins turbines. As the turbine spins, electricity is generated.

On a smaller scale, geothermal heat pumps can be used for temperature control in homes and buildings. An electric heat pump moves heat between your home and a geothermal well, where temperatures are constant and close to average annual air temperatures. In the summer, the heat pump takes heat from your home and moves it to the well, and in the winter, it pulls heat from the ground to heat air for your home. 

Heat pumps can also be used for hot water, although geothermal HVAC systems are more common.

What are the advantages of geothermal energy?

As a renewable resource, there are a few key geothermal energy benefits to consider that make it a viable option for energy generation and space heating. The top advantages of geothermal energy include:

• It’s reliable

• No risk of depletion

• No carbon emissions

• Minimal space required

• Lots of potential 

1. Geothermal energy is reliable

One of the biggest advantages of geothermal energy is that it’s reliable. Unlike solar and wind, geothermal energy is highly reliable even without a means of energy storage. 

The temperature at depth is constant, so the system won’t suffer from underproduction in certain weather conditions. Therefore, geothermal energy bridges the gap between highly reliable energy from burning fossil fuels and less reliable power from other renewable energy sources.

2. Geothermal energy releases no carbon emissions

Part of what makes geothermal a great energy source is that it doesn’t release harmful greenhouse gases like carbon dioxide into the atmosphere when it generates power. 

Geothermal energy is 100% clean in terms of greenhouse gases and emissions, and it doesn’t contribute to climate change. There are no emissions from the power production process other than steam.

3. Geothermal plants don’t deplete their heat source

Geothermal energy is considered a renewable resource, meaning it doesn’t get “used up” as we call on it for heat or electricity. So, using a geothermal power system doesn’t change the temperature below the surface.

This is in direct contrast to fossil fuels, which have a limited supply. Each time we use coal or natural gas, there is less of it for us to use later on, and it will eventually be depleted. 

4. Geothermal energy equipment has low space requirements

Most of the equipment you need to install to take advantage of geothermal energy as an individual homeowner sits underground, which means you generally don’t need a large property or to take up much space in your home or yard to reap the benefits. This is especially true compared to something like solar energy, which requires a full roof of panels or large solar farms for utility-scale power generation.

This is true for large-scale geothermal energy plants, too. According to a report by the Department of Energy, geothermal power plants require less land to produce the same amount of power as coal power plants, wind farms, and solar power stations. 

5. Geothermal energy has massive potential

A report by the International Energy Agency revealed that global energy demand increased by over 2% in 2024, and will likely continue to increase in years to come. We need to find new and innovative ways to power our society to meet the ever-growing electricity demand. The heat stored within the Earth could be key in creating a sustainable energy future. 

Geothermal energy has the potential to generate up to 15% of global electricity demand growth to 2050. Right now, it meets under 1% of global energy demand. There is lots of potential to expand geothermal energy to meet our electricity needs as they grow. 

What are the disadvantages of geothermal energy?

Of course, there are some drawbacks to geothermal energy, too. Some of the main disadvantages of geothermal energy include that it’s location-specific, has high upfront costs, and can impact the environment. 

1. Geothermal energy is location-specific

Drilling 40 feet down for a geothermal power plant or ground source heat pump is possible in most areas, but not everywhere. High altitude areas may need to drill deeper, driving up installation costs. Drilling deep wells where the water table is high, like in coastal areas, also isn’t always possible. Some areas are better suited than others, which limits geothermal’s potential. 

2. Geothermal systems have high upfront costs

Geothermal equipment is expensive, and so is the labor to excavate and install everything. Evaluation and excavation may make it more expensive than wind and solar solutions that are installed above-ground. 

3. Geothermal energy can impact the surrounding environment 

While geothermal energy is sustainable when it comes to emissions, the practice of drilling into the earth either to create ground loops for space heating or to expose sources of heat for geothermal plants raises concerns related to inducing earthquakes and weakening the Earth’s crust. Excavating large amounts of the Earth can also disturb the surrounding area and disrupt the local ecosystem. 

How to make use of this renewable energy source at home

Unlike installing solar panels, installing a geothermal system won’t give you access to electricity at home, as it’s not possible to install the type of geothermal energy system that extracts heat to spin a turbine and generate power like it is at a utility scale.

However, most homeowners can opt to install a geothermal heating and cooling system, which uses an electric heat pump to exchange heat between a well and your living space. These systems are extremely efficient, and short of the high heat pump installation costs and temporary disruption to a portion of your lawn, they’re a great option for sustainability in both heating and cooling. 

Since more than 40% of your utility costs go toward maintaining a comfortable living space, a geothermal heat pump system, while expensive upfront, can end up paying for itself and providing net savings over time.

If you live in an area where geothermal energy plants are prevalent and you’re in a state with a deregulated energy market, you might be able to find an energy plan that includes 100% renewable energy from geothermal sources. This would allow you to take advantage of clean energy without high upfront costs and without disrupting your lawn by installing a geothermal heat loop.

Alternatives to geothermal energy

Since geothermal energy is largely location-dependent and has a very high installation cost, you may want to consider some alternatives that can still reduce your carbon footprint and save you money on those steadily increasing electric bills.

• Wind power: Installing wind turbines isn’t feasible for individual homeowners, but if you live in a flat, open area like Texas, Iowa, Kansas, Oklahoma, or the Dakotas, you may have access to affordable wind power through your electricity provider.

• Hydropower: Hydropower uses natural water movement to spin water turbines that generate electricity. Like wind power, it’s not a technology you can install on your property as an individual, but if you live in Washington, Oregon, or California, especially, you may have access to this renewable resource through your utility company.

• Biomass: Biomass makes use of dead plant matter to generate electricity. A common biomass source is creating ethanol fuel from corn, but this is only feasible for large-scale production. However, you could install a biomass furnace in your home that uses wood, wood pellets, or other plant matter as a fuel instead of natural gas or oil.

• Solar energy: Going solar is the simplest and often the most affordable way for homeowners to make their homes more sustainable and save on their electric bills. You can install rooftop home solar panels or ground-mount panels to reduce or even eliminate your monthly bill. Depending on where you live, you may also be able to opt into community solar, which should save you money on your electric bills and reduce your carbon footprint without installing and maintaining equipment.