Image caption: Geothermal power plants that tap into the planet’s heat, like the Nesjavellir Geothermal Power Plant in Þingvellir, Iceland that’s pictured above, have the potential to generate round-the-clock, carbon-free electricity. Photo credit: Gretar Ívarsson, geologist at Nesjavellir, edited by Fir0002/Public Domain
Script by: Megan Chan | Audio by: Jericho Rajninger | Blurb by: Keya Pardasani
What is Geothermal Energy?
Geothermal energy is heat generated in the earth. It is a renewable source of energy, and it is extracted from the inner earth for energy use. Typically, geothermal energy is harnessed through holes that are drilled allowing hot water or steam to be extracted. These resources then drive a turbine to generate electricity and energy. Harnessed in this way, geothermal energy has significantly fewer environmental impacts than fossil fuels.
The Pros and Cons of Geothermal Energy
Geothermal energy can provide base load power—available 24/7—which is generally not the case for wind and solar. Wind and solar are intermittent resources, requiring energy storage to be able to match energy demand during times when the wind is not blowing or the sun is not shining. Second, deriving energy from geothermal sources can be done highly efficiently, with less energy than from other sources. Dependability and cost make geothermal energy an appealing option under the right conditions.
However, like other forms of energy, geothermal energy also comes with drawbacks. Geothermal resources may be finite, as they can cool over time. Additionally, there is a high upfront investment cost for geothermal energy. Considering both the positives and negatives of geothermal energy is crucial for understanding future feasibility of this energy source.
What’s Next for Geothermal Development?
The US is currently the leader in geothermal energy, and policies and development of the resource may be expanding. Colorado has launched “The Heat Beneath Our Feet” initiative, which supports the development of geothermal energy generation. Additionally, the US Department of the Interior has voiced its support in favor of geothermal energy, for it believes that the expansion of geothermal energy carries many benefits.
The United States also produces the most geothermal energy, with California producing the second most geothermal energy after Nevada. As a result of new research and technology, we may only be tapping the surface (so to speak) of available geothermal energy. By some estimates, the United States is using less than 1% of the available geothermal energy. With developing technology, there is hope that this untapped energy can be accessed more broadly and in a cost effective manner.
About our guest
Pat Dobson is a staff scientist leading the geothermal assistance program at Lawrence Berkeley National Lab. He has many years of research experience, and focuses on volcanic rock and the effects of water-rock interaction. This has been the focus of much of his research and publications, and he is currently working on field and coupled process modeling studies of The Geysers with Lawrence Labs and Sanford Underground Research Facility.
- National Geographic, Encyclopedia entry: Geothermal Energy (2022)
- GreenMatch (UK), Advantages and Disadvantages of Geothermal Energy – The Source of Renewable Heat (2023)
- National Renewable Energy Laboratory (NREL) Full Steam Ahead: Unearthing the Power of Geothermal
- U.S. Department of Interior, Geothermal Energy Development, Statement of Tim Spisak (2019)
- Western Governors’ Association, The Heat Beneath Our Feet
- Center for Sustainable Systems, University of Michigan, Geothermal Fact Sheet (2022)
Ethan: I’m Ethan Elkind, and you’re listening to Climate Break. Climate solutions in a hurry. Today’s proposal: Using geothermal energy to generate round-the-clock, carbon-free electricity. Pat Dobson at Lawrence Berkeley National Lab explains how power plant operators can extract the geothermal energy from heat zones deep within the Earth.
Dr. Dobson: We drill bore holes into those zones and we extract hot water or steam from those resources. And we either flash the hot water to steam, by lowering the pressure, or we pass it through a heat exchanger and flash another working fluid. The steam or this, this working fluid would then drive a turbine and generate electricity.
Ethan: This carbon-free source of electricity provides reliable and consistent power.
Dr. Dobson: It provides a baseless source of, of power. And so intermittent, uh, renewable energy sources such as wind or solar: if the sun’s not shining, if it’s a cloudy day, if it’s nighttime, if the wind’s not blowing, you’re not generating electricity.
Ethan: Dobson explains that the big challenge facing geothermal energy right now is the high cost of drilling. The US Department of Energy’s Earthshot project is seeking to address this challenge.
Dr. Dobson: One of the objectives of the Earthshot is to make it economically viable and competitive with other types of renewable energy sources. It’s going to involve lowering the cost of drilling dramatically. And also lowering the risks associated with exploration and development of these resources. And making sure that the resource can be operated in a sustainable manner for long periods of time.
Ethan: Dobson also says that bolstering capacity for governments to conduct environmental review could help lower costs. To learn more about geothermal energy, visit climatebreak.org