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. 

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. 

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.

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)

For a transcript, please visit https://climatebreak.org/geothermal-power-tapping-earths-heat-for-a-carbon-free-future/