Is Geothermal A Potential?

Geothermal energy harnesses the heat from underneath the earth’s surface to generate renewable power. This heat can be extracted from hot water or steam reservoirs found deep underground and used to drive turbines that produce electricity. Geothermal is unique among renewable sources because it provides constant baseload power, unlike intermittent sources like solar and wind. With enormous untapped potential still untapped globally, geothermal may play a key role in the transition to clean energy. This article will provide an in-depth look at the potential of geothermal energy.

What is Geothermal Energy?

Geothermal energy is thermal energy generated and stored in the Earth (https://www.energy.gov/eere/geothermal/geothermal-basics). It is a renewable energy source that utilizes the natural heat within the earth’s crust to produce heat and electricity. The word “geothermal” comes from the Greek words geo (earth) and therme (heat) (https://www.eia.gov/energyexplained/geothermal/).

There are several types of geothermal energy systems that take advantage of the earth’s heat in different ways:

• Hydrothermal systems utilize hot water reservoirs found deep underground, often near tectonic plate boundaries.
• Enhanced geothermal systems (EGS) inject water into hot dry rock reservoirs to create an artificial geothermal reservoir.
• Direct-use systems use geothermal reservoirs near the earth’s surface to directly heat buildings, grow plants, or for other applications.
• Geothermal heat pumps use stable ground or water temperatures near the earth’s surface to control building temperatures above ground.

In each system, wells and pumps bring the thermal energy to the surface as electricity, direct heating, or cooling. Geothermal energy is considered renewable since heat is continuously produced inside the earth.

Geothermal Energy Pros

Geothermal energy has many advantages that make it an attractive renewable energy source. Some of the main pros of geothermal energy include:

It is renewable and sustainable. Geothermal energy taps into the natural heat within the earth, which is constantly being replenished and will never run out (1). This makes it a reliable long-term energy solution.

It provides constant baseload power. Unlike solar or wind power which depend on weather conditions, geothermal plants can generate electricity 24/7, 365 days a year (2). This makes geothermal a stable energy source.

It has low emissions. Geothermal energy has emission rates ranging from just 6 to 30 grams of CO2 per kWh, which is far lower than fossil fuels. This helps reduce greenhouse gases (3).

It has a small land footprint. Geothermal plants take up less land area compared to other renewable sources. The actual facility covers just a few acres, reducing environmental impact (1).

It contributes to grid stability. Geothermal provides constant “base load” power, which helps stabilize the electricity grid when renewables like solar/wind fluctuate in output (2).

It creates jobs & economic development. Constructing geothermal plants creates many skilled jobs. Once running, the plants provide employment opportunities for the local community (4).

It is suitable for a range of applications. Geothermal energy can be used for electricity generation, district heating, greenhouse heating, industrial processes and more (5). This versatility also makes it attractive.

Sources:
(1) https://www.enelgreenpower.com/learning-hub/renewable-energies/geothermal-energy/advantages
(2) https://www.twi-global.com/technical-knowledge/faqs/geothermal-energy/pros-and-cons
(3) https://www.geothermal.org/our-impact/blog/all-advantages-geothermal
(4) https://www.enelgreenpower.com/learning-hub/renewable-energies/geothermal-energy/advantages
(5) https://www.enelgreenpower.com/learning-hub/renewable-energies/geothermal-energy/advantages

Geothermal Energy Cons

While geothermal energy has many advantages, it also comes with some drawbacks and limitations:

High upfront costs – Drilling geothermal wells and installing the power plant equipment can cost millions of dollars upfront before any power is generated, making the initial investment significant [1].

Location specific – Geothermal power is only feasible in locations with adequate underground heat and permeability, limiting where plants can be built [2].

Resource depletion – Geothermal reservoirs can be depleted over time if fluids are extracted faster than replenished, requiring site management to sustain the resource [2].

Surface instability – There are concerns geothermal drilling could lead to increased seismic activity or instability, though evidence suggests it is low risk with proper precautions [1].

Land use conflicts – Large geothermal plants can require substantial surface land areas, potentially leading to conflicts over land use with other priorities like conservation [1].

Global Geothermal Energy Use

Geothermal energy currently provides less than 1% of total global electricity generation. According to the International Renewable Energy Agency (IRENA), the global installed capacity for geothermal power generation was around 16,000 megawatts (MW) as of 2021, generating around 95 terawatt-hours (TWh) of electricity annually (https://www.irena.org/Publications/2023/Feb/Global-geothermal-market-and-technology-assessment).

The countries with the most installed geothermal capacity are the United States, Indonesia, Türkiye, New Zealand, Mexico, Iceland, Kenya, Japan, Italy, and the Philippines. Some key examples of geothermal utilization include:

• The United States has around 3,800 MW of installed geothermal capacity, generating about 17 TWh of electricity in 2021 (https://www.eia.gov/energyexplained/geothermal/use-of-geothermal-energy.php).
• Indonesia has around 2,100 MW of installed capacity and is the second highest geothermal electricity producer after the US.
• New Zealand obtains about 15% of its electricity from geothermal power plants.
• Iceland generates about 30% of its total electricity from geothermal energy.

Several other countries also meet significant shares of their electricity demand from geothermal power, including Kenya (49%), El Salvador (25%), and Costa Rica (12%). Overall, geothermal energy represents a small but growing part of renewable energy generation worldwide.

Geothermal Potential in the US

Geothermal energy shows significant potential for expansion in the United States. According to the U.S. Department of Energy, the estimated geothermal power resource potential for the US is approximately 530 gigawatts (GW) [1]. To put this in perspective, the current installed geothermal electricity capacity in the US is around 3.7 GW as of 2019 [2]. This demonstrates there is still abundant untapped geothermal resource available.

The Western states, including California, Nevada, Utah, Hawaii and Idaho, offer the greatest potential due to ideal geothermal conditions with access to high temperature reservoirs [3]. With supportive policies, continued technological advances, and drilling cost reductions, the geothermal market could expand significantly in these key states.

The U.S. federal government and some state governments provide tax incentives to promote geothermal development. These policy supports help improve the economic feasibility of geothermal projects. Continued incentives and initiatives to unlock geothermal resources could help the U.S. tap more of its vast potential.

Key Geothermal Resources in the US

The western United States, specifically California, Nevada, Utah, and Oregon, have the greatest geothermal resource potential in the country ¹. High temperatures close to the earth’s surface make these areas ideal for geothermal power generation. According to the U.S. Geological Survey, over half of the geothermal power capacity in the U.S. is located in California’s Imperial Valley and The Geysers in Northern California ².

Other states with significant geothermal resources include Idaho, New Mexico, Colorado, Alaska, and Hawaii. Hawaii, in particular, generates over 25% of its electricity from geothermal sources. While geothermal projects require specific geological conditions, improved technologies are helping to expand geothermal energy production to new regions across the country.

Challenges for Geothermal

While geothermal energy has many benefits, there are also challenges facing greater deployment. Some key challenges include:

Technical challenges:

• Drilling to great depths can be difficult and expensive. Geothermal wells are deeper than gas or oil wells (RFF.org).
• There are risks of hitting dry wells that lack enough hot water or steam (RFF.org).
• The geothermal fluid can be corrosive and require specialized materials (RFF.org).

Economic challenges:

• High upfront capital costs for drilling and plant construction (Twi-Global.com).
• Longer payback periods compared to other energy sources (Twi-Global.com).

Policy challenges:

• Permitting for drilling and power plants can be lengthy and complex (RFF.org).
• Lack of tax incentives and favorable policies compared to other renewables (RFF.org).

Additionally, geothermal is restricted to suitable geological locations, so it cannot be easily scaled up nationwide. Ongoing research into enhanced geothermal systems seeks to mitigate some of these challenges and expand geothermal potential (RFF.org).

Future Outlook

Experts project significant growth for geothermal energy in the coming years and decades, both globally and in the United States. According to an analysis by MIT, global geothermal power capacity could grow over 26-fold, from 12.8 GW in 2015 to 340 GW by 2050 (The Future of Geothermal Energy). The International Renewable Energy Agency (IRENA) forecasts global geothermal capacity reaching over 127 GW by 2030 in their accelerated renewable energy scenario.

In the US, one projection estimates geothermal capacity growing from just under 4 GW today to 60 GW by 2050, a 15-fold increase (Full Steam Ahead: Unearthing the Power of Geothermal). This growth will be driven by advances in enhanced geothermal systems (EGS) technology and discovery of new conventional hydrothermal resources. Key areas for growth include the Western US, Alaska, Hawaii, and Gulf Coast region.

Realizing this potential will require surmounting technical and economic hurdles, as well as continued research, development and demonstration of EGS. If these challenges can be met, geothermal is poised to make a major contribution to a renewable energy future in the coming decades.

Conclusion

In summary, geothermal energy has significant potential as a renewable energy source, though it also faces some challenges. The key advantages of geothermal are that it provides constant base load power, has a small land footprint, produces minimal emissions, and utilizes an abundant resource. The main drawbacks are high upfront capital costs and the geographical limitation that a site must have adequate heat and permeability. However, advances in technology are helping expand the range of suitable locations.

The western United States, Alaska, and Hawaii host the most promising geothermal resources. With the ability to provide constant, emissions-free baseload power, geothermal should be considered among the renewables that can play a major role in a clean energy future, especially for direct heating applications and balanced power generation portfolios. While upfront costs are high, geothermal offers great value as a durable long-term energy solution. With continued research and technological improvements, geothermal can aid the transition away from fossil fuels.