How Does Geothermal Energy Work? Easy to Understand Guide from the Experts

There are three types of geothermal energy:
• Geothermal power plants that produce electricity
• Direct use and direct heating systems
• Geothermal heat pumps
Let’s explore each of these exciting natural possibilities. Why? So, we can use the earth to save the earth.
Across the United States and around the world, there are reservoirs of hot water. This water can be found near the earth’s surface, or deeper down. The water is extremely hot, with temperatures ranging from 300° to 700°F. Geothermal power plants use the steam from the hot water to produce electricity.
It’s a simple process. The steam creates energy that rotates a turbine. The turbine activates a generator and electricity is produced. And this is a natural resource, so we’re using these reservoirs in the earth to power the earth.
Geothermal power plants are built where the reservoirs of hot water are located. In the U.S., most of the reservoirs are in the western states, but there are also reservoirs in the South, Midwest, and East Coast. This means that we can be using this natural resource more than we are currently.
And scientists and engineers are working on innovative technologies that will allow geothermal power plants to be built anywhere around the world, serving clean and renewable electricity at any time!

There’s another kind of geothermal energy that’s readily available called geothermal direct heat. It’s a simple process: direct heat comes from the water found in rock beneath the earth’s surface. The hot water in the rock reservoirs produces heat and steam, but isn’t hot enough to be economical to generate electricity. This water is captured and piped into buildings to provide heat, melt ice on roads and sidewalks, and warm fishing farms, greenhouses, and swimming pools.
Direct heat systems are already in use all around the world to make our lives better. For example, direct heat systems provide heat for most of the buildings in Reykjavik, Iceland. Direct heat is also used for food dehydration, pasteurizing milk, and mining gold. It’s an easily accessible and effective geothermal energy source.

Finally, there are geothermal heat pumps. These heat pumps work by using the heat that naturally occurs in the ground. Did you know that temperatures in the earth 10 feet below ground range from 50°F to 60°F. This means that soil temperatures are typically warmer in the winter and cooler in the summer than the air. Geothermal heat pumps use the earth’s temperature to heat and cool buildings. How? During the winter, heat pumps take the heat from the ground into buildings. The process is and reversed during the summer.
According to the U.S. Environmental Protection Agency (EPA), “geothermal heat pumps are the most energy-efficient, environmentally clean, and cost-effective systems for heating and cooling buildings. All types of buildings, including homes, office buildings, schools, and hospitals, can use geothermal heat pumps.” In addition to heating and cooling buildings, geothermal heat pumps can provide hot water. Best of all, this is clean, renewable energy.

As demand for energy increases, geothermal energy will become an increasingly important energy source. Right now, California has 43 operating geothermal generating plants, and plans to build more. A 2019 U.S. Department of Energy (DOE) report, GeoVision: Harnessing the Heat Beneath Our Feet, says, “generating electricity through geothermal methods could increase 26-fold by 2050, providing 8.5 percent of the United States’ electricity, as well as direct heat.” And, in Boise, Idaho, geothermal energy is heating 92 of biggest buildings in the city.
Let’s all embrace geothermal energy: a clean, green, renewable energy that uses the earth to power the earth.

https://www.eia.gov/energyexplained/geothermal/geothermal-heat-pumps.php
https://www.eia.gov/energyexplained/geothermal/use-of-geothermal-energy.php
https://www.go-gba.org/resources/green-building-methods/geothermal-energy/
https://www.energy.gov/eere/geothermal/electricity-generation
https://e360.yale.edu/features/can-geothermal-power-play-a-key-role-in-the-energy-transition
https://www.energy.gov/eere/geothermal/downloads/geovision-harnessing-heat-beneath-our-feet
Executive Director's Message -- April 2022

Earth’s heat is ubiquitous. It’s everywhere below our feet at all times. All we need to do is drill deep enough and we’ll access a limitless supply of energy, available anywhere and at any time.
That makes geothermal technologies very versatile. We can use that subsurface heat energy for power generation, direct heat use for communities, heavy industry, and commercial buildings, and geothermal heat pumps for heating and cooling residential properties and businesses.
When we consider this holistic view of using Earth’s heat then the possibilities become extraordinary, unique, and very exciting. It means that as we transition to a carbon-neutral world over the next few decades then geothermal energy will play a critical linchpin role.

The realization of that role has led to an acceleration of activity in the geothermal market that includes:
- research, development, and demonstration of new technologies;
- entrepreneurs and startup companies receiving more investment monies; and,
- new partnerships being developed between governments, academia, and industry.
The geothermal community is a part of the wider renewables community. We need to work together as a renewables community to secure a successful transition to a clean and sustainable energy ecosystem for the good of our planet, our civilization, our economies, and our health and wellbeing across society.
The energy transition requires the following four actions to minimize the impact of climate change and build out an energy ecosystem that will work in practice:
- electrify everything we can in our daily lives;
- deliver zero-carbon, reliable, and sustainable electricity;
- optimize the efficiency of all our energy use; and,
- develop robust and long-term carbon and energy storage.
And we need to do these things with haste, which means we need to run all these actions in parallel and accelerate deployment in earnest. If we examine the opportunities for geothermal energy within the energy transition then we can understand how it will play that critical linchpin role.

As we build the technologies that enable scaling and accessibility of geothermal energy anywhere, at any time, then we have a huge opportunity to create impactful social and environmental justice due to Earth’s heat being widespread and technologically versatile.
Its 24/7 firm clean energy source provides reliability, resiliency, sustainability, and efficiency to a power grid that also uses intermittent energy sources and storage.
It will allow our power delivery to efficiently adapt to changing patterns of demand (diurnally and annually) as we electrify everything in our lives and robustly work through changing weather patterns and extreme weather events.
That same firm clean energy source will provide optimized heating and cooling efficiencies at different scales from an individual home to heavy industrial use.
With the help of an integrated and systemic energy policy that optimizes the use of all renewable technologies together then the decarbonization of heating and cooling, along with electrification and storage, will allow us to realistically make it to a 100% clean and renewable society.

Geothermal Energy: The Renewable Energy Source That Can Save Us All

There’s a lot of talk about impending climate doom. Make no mistake: if we don’t find clean, renewable sources of energy, we are certainly done for. The good news is we’ve already found a clean, renewable energy source that can save us all. It’s called geothermal energy.
If you’ve never heard of geothermal energy before, it might sound complicated or intimidating. But it’s really simple: geothermal energy is the energy from within the Earth.

Think back to elementary school science class. Remember learning about potential energy? Potential energy is energy that is stored, ready to be turned in to kinetic energy—energy in action.
Ok, now remember learning that heat rises? Even if you didn’t learn it in school, you’ve seen it in life. That’s why it’s usually warmer upstairs. That’s why hot water boils. That’s why hot air balloons float. Heat turns potential energy into kinetic energy.
The Earth is literally full of potential energy.
The Earth has many layers. The surface, or the crust—where we all live—may seem cold and hard. But dig a little deeper, and things get hot, fast. The center of Earth, the core, is as hot as the surface of the sun. This heat within the Earth rises, too.
The heat within the Earth is renewable because it will never run out. The core will always be hot, and heat will always rise.

You can see geothermal energy in action around the world. When Old Faithful spouts water high in the sky or Mt. Kilauea erupts, it’s because the heat from within the Earth rises and converts potential energy to kinetic energy.
Not all examples of geothermal energy are so explosive. Icelanders cook their famous hverabrauð, or lava bread, by burying a dough made of flour, buttermilk, and a few other ingredients in a metal container near geothermal steam vents that naturally occur throughout the country. 24 hours later, geothermal energy turns this dough into delicious rye bread.
Iceland doesn’t just use geothermal energy to bake bread. Geothermal energy powers 30% of Iceland’s electricity.

So, if the Earth holds all this potential energy, why aren’t we using it?
One reason is that we haven’t always had the technology to access geothermal energy around the world. Places where heat from within the Earth naturally rises to the surface, like Iceland and New Zealand, have always used geothermal energy—to bake bread, relax in hot springs, and heat their homes.
Today we have the technology to use geothermal energy to sustainably power daily life around the world. In fact, many of the tools we use to access unsustainable fossil fuels can be repurposed for unlocking this clean, renewable energy source. This will help ease and speed up the transition from a limited energy source that hurts the planet to an energy source that helps the planet that will never run out.
The main reason geothermal energy is not used today is that few people know about it. If people do know about it, they associate it with violent Earth events, like volcanoes. We can change that.
The Earth has enough renewable energy to save us all, if only we take steps now to use it.
Join us as we work to use the earth to save the earth.
Geothermal Rising 2022 Strategic Plan

Elements of the Strategic Plan
● Vision = What we want for the world.
● Mission = How we will achieve our vision.
● Goals = Our general long-term aspirations for the organization.
● Objectives = How we will achieve our goals in the given time frame.
Vision
A brighter future for Earth and all its inhabitants, powered by the planet itself.
Mission
To connect the geothermal community and champion geothermal energy in the United States and
around the world.
Goals
● Broaden awareness of geothermal energy and its important role in the energy transformation.
● Build positive public sentiment towards geothermal energy as a clean, renewable, and
ubiquitous energy source.
● Empower the geothermal community to advance through, technological innovation, education
and collaboration with other sectors
● Expand the demand for and use of geothermal energy.
Objectives
1. Raise Public Awareness of Geothermal Energy – increase the visibility of geothermal energy
through marketing and communications activities that inform and educate across a wide spectrum of organizations, agencies, and people.
2. Champion Innovation – serve as a platform for inspiring, encouraging and sharing new technologies that will accelerate the deployment of geothermal energy in an agnostic way.
3. Build an Enabling Environment for Geothermal Energy – work with government and regulatory agencies to incentivize demand and adoption of geothermal energy.
4. Expand GR’s Activities to Grow the Geothermal Industry – build a strong membership base of
individuals and corporations and arm them with the tools they need to engage outside the geothermal community.
5. Maintain Financial Sustainability – operate with a budget surplus through self-supporting activities.
6. Enhance Internal Processes – improve the professional quality of our products and services and integrate the functions of the GR team.
A PDF of the announcement letter can be downloaded in the upper right of this page.
President's Message -- March 2022

After a couple of busy years and a lot of change for Geothermal Rising and the geothermal community across the globe, we are looking forward to a productive year in 2022!
Geothermal Rising will be determining the best way to tap into our talented membership to create an impact on geothermal outreach in the US and globally, and will work to increase Geothermal Rising membership by 20%, and finally, strive to coordinate geothermal messaging across local and global geothermal associations.

Geothermal Rising’s volunteers have been working, growing and thriving over the last couple of years. This includes the Student Committee which have been putting on webinars, networking and training opportunities, and growing its social media presence exponentially. The Diversity, Equity and Inclusion Task Force has done incredible work over the last couple of years driving forward its goals and working to increase inclusivity within the Geothermal Rising membership that we hope will effect change on the broader industry. Lastly, the Communications Committee has been essential to our marketing improvements within Geothermal Rising and will have a large role in celebrating the 50th year anniversary for the association this year!
As the new President of Geothermal Rising, I have a million ideas about ways to help the geothermal industry and community throughout 2022. However, keeping that list short and impactful will be the goal. Please reach out to me with any thoughts, comments, questions, ideas you may have at grpres@geothermal.org.

Recommendations for Implementing Geothermal Demonstration Programs

Geothermal Rising
1121 L Street, Suite 700
Sacramento, CA 95814
March 2, 2022
Recommendations for Implementing Geothermal Demonstration Programs
This memo provides recommendations for implementation of geothermal demonstration programs within the U.S. Department of Energy (DOE).
Geothermal energy has the potential to provide massive amounts of clean electricity, heat, and storage. In its landmark GeoVision report, DOE described geothermal as an “always-on source of secure, reliable, and flexible domestic energy that can be utilized across industrial, commercial, and residential sectors.” By DOE’s estimate, geothermal could provide over 120 GW of clean, 24/7 electricity by 2050. Since GeoVision was published in 2019, geothermal innovators and DOE-supported projects are demonstrating a path to unlock these resources. With co-funded investment and strong policy support, the geothermal industry can unleash its full potential.
The Infrastructure Investment and Jobs Act (IIJA) of 2021 provides a unique opportunity to unlock the immense potential of geothermal energy. The IIJA includes several demonstration programs that are well suited to geothermal, including $84M for enhanced geothermal systems (EGS) and several programs under the new DOE Office of Clean Energy Demonstrations (OCED), including: regional hydrogen hubs; long-duration energy storage; clean heat for industrial applications; clean energy projects on current and former mine land; energy improvements in rural and remote areas; and upgrading the electric grid to ensure reliability and resilience.
The recommendations below are focused on supporting successful implementation of 1) the EGS Demonstration Program and 2) demonstration programs included in DOE’s OCED.
Enhanced Geothermal Systems (EGS) Demonstration Program
As DOE’s GeoVision report shows, EGS is a promising technology for deploying vast amounts of clean geothermal energy. To support geothermal’s growth, the IIJA included $84M for EGS demonstration projects from FY22 to FY25, as authorized by the Energy Act of 2020. The Energy Act directs DOE to fund four EGS demonstration projects for power production or direct use, utilizing diverse geologic settings and development techniques. Moreover, at least one project must be located east of the Mississippi River.
DOE should strive to issue its first funding opportunity before the end of FY22. To ensure a successful EGS Demonstration Program, DOE should focus on technological diversity, geographic diversity, use-case diversity, and a milestone-based approach. Each of these is explained in further detail below:
● Technological Diversity: DOE’s GeoVision report includes a broad but clear definition of EGS. Specifically, GeoVision defines EGS as unconventional geothermal resources that “contain heat similar to conventional hydrothermal resources but lack the necessary groundwater and/or rock characteristics to enable energy extraction without innovative subsurface engineering and transformation. Unconventional EGS resources can be found at any above-ambient temperature that supports energy conversion for a given end-use technology application.”
DOE’s definition of EGS is broad, allowing for a range of innovative subsurface technologies that can be applied to multiple use cases, including power generation and direct use. As such, DOE’s funding opportunities should follow the definition of EGS in the GeoVision report, applied across a diversity of geologic settings. This will ensure consistency across funding opportunities, provide clarity to potential applicants, and encourage a wide range of technologies to compete.
● Geographic Diversity: The Energy Act also requires demonstration projects to collectively demonstrate different geologic settings, such as hot sedimentary aquifers, layered geologic systems, supercritical systems, and basement rock systems. A mixture of geographic, geologic, and technical diversity can expand the scope of geothermal energy’s potential applications. To the extent possible, DOE should prioritize locations that demonstrate evidence of promising subsurface characterization.
● Use-Case Diversity: Geothermal has promising applications in power generation, direct use, thermal storage, clean heat for industry, and mineral recovery. The EGS Demonstration Program is authorized to fund projects in both power generation and direct use, so DOE’s funding opportunities should be written to be inclusive of all allowable use cases. The next section will explain how DOE can leverage other IIJA demonstration programs to fund promising geothermal projects with thermal storage and clean heat applications, among others.
● Milestone-Based Approach: DOE is explicitly authorized to utilize a milestone-based approach for the EGS Demonstration Program, as described in Section 9005 of the Energy Act. The Department should pursue this structure, while incorporating the best practices of the successful NASA COTS program, to the extent applicable. Section 9005 provides a clear framework for ensuring consistency, transparency, and accountability in funding opportunities. Crucially, the milestone-based approach includes specific “technical and financial milestones, including estimated project timelines and total costs.” By setting clear expectations, DOE can provide effective program management, mitigate risk, and maximize the impact of taxpayer resources.
DOE Office of Clean Energy Demonstrations (OCED)
In addition to the EGS Demonstration Program, the IIJA established a new DOE Office of Clean Energy Demonstrations (OCED) to support a wide range of clean energy technologies. The IIJA included several programs under OCED for which geothermal is both eligible and uniquely suited to compete, including:
● Regional Clean Hydrogen Hubs $8B ($1.6B for FY22, FY23, FY24, FY25, and FY26)
○ The IIJA includes $8B for DOE to fund at least four regional clean hydrogen hubs. The statute requires at least one project to demonstrate hydrogen production from renewable energy, which can include geothermal. The statute also requires diverse end-uses, including electric power, industrial, residential and commercial heating, and transportation. Geothermal could play a strong role in any of these end-use sectors, particularly residential and commercial heating.
● Energy Storage Demonstration Projects and Pilot Grant Program $355M ($88.75M for FY22, FY23, FY24, and FY25)
○ DOE is directed to fund three energy storage demonstration projects by Sep. 30, 2023 and establish a separate pilot grant program. Geothermal’s potential as a source of seasonal thermal storage makes it well suited to compete for funding under both programs.
● Long Duration Demonstration Initiative and Joint Program $150M ($37.5M for FY22, FY23, FY24, and FY25)
○ This is a joint program between DOE and the U.S. Department of Defense (DoD) to demonstrate long-duration storage technologies at DoD facilities and installations. DOE should ensure effective coordination with the Navy Geothermal Program Office, which is DoD’s lead agency for geothermal development.5
● Industrial Emission Demonstration Projects $500M ($100M for FY22 and FY23, $150M for FY24 and FY25)
○ This program is focused on demonstrating diverse technologies for reducing emissions in the industrial sector. Geothermal has significant potential as a source of clean heat to drive deep decarbonization of hard-to-abate heavy industrial sectors.
● Clean Energy Demonstration Program on Current and Former Mine Land $500M ($100M for FY22, FY23, FY24, FY25 and FY26)
○ Under this program, DOE is directed to fund not more than five clean energy demonstration projects on current and former mine land. Geothermal is explicitly included in the definition of “clean energy project” along with several other technologies.
● Energy Improvements in Rural And Remote Areas $1B ($200M for each FY22, FY23, FY24, FY25, and FY26)
○ The IIJA appropriates $1B over five years for OCED to support “energy improvements in rural and remote areas,” which can include generation resources, microgrids, and grid modernization, among others. Given geothermal’s significant production potential in rural and remote areas, the geothermal industry is well positioned to contribute to the program.
● Program Upgrading Our Electric Grid and Ensuring Reliability and Resiliency $5B ($1B for FY22, FY23, FY24, FY25, and FY26)
○ Under this program, DOE is directed to collaborate with the electric utility sector to demonstrate innovative grid reliability and resilience technologies. Given its capabilities as a firm and flexible resource, geothermal can play a key role.
The IIJA demonstration programs provide an unprecedented opportunity for geothermal. The $84M EGS Demonstration Program is an important foundation to de-risk and scale geothermal projects, while several programs under DOE’s OCED offer geothermal the opportunity to demonstrate its cross-cutting capabilities in energy storage, industrial decarbonization, rural development, and grid reliability. By prioritizing the above recommendations, DOE can help geothermal reach its full potential while maximizing the benefits of its IIJA demonstration programs.