When we think about Utah’s clean renewable energy resources, solar and wind likely top the list. Yet there’s another option with limitless possibility. Geothermal energy is literally the heat beneath our feet, and it offers the potential for providing a nonpolluting, renewable and virtually inexhaustible source of energy.
Using the energy below the Earth’s surface isn’t new. For millennia, humans used the thermal energy manifested in hot springs for cooking and cleaning. Today, geothermal water is used for spas, space heating, agriculture, aquaculture and electric generation.
In southern Utah, poinsettias and chrysanthemums are grown in greenhouse complexes heated with geothermal water. Boise, Idaho, has used hot water to heat buildings since 1892. And the Carolyn and Kem Gardner Commons Building at the University of Utah is heated and cooled entirely by energy extracted from the earth, saving some $70,000 annually in energy bills.
Utah is also home to three geothermal power plants producing a combined 72 megawatts of electricity, or enough to supply about 72,000 homes.
For all of its attributes, there is an obstacle to wider adoption of geothermal energy. Currently, it is produced in areas where hot waters reach the surface forming hot springs. These natural geothermal systems require three components: heat, water to transport the heat toward the surface and permeable pathways in the hot rock for the water to extract the heat.
In 2019, the U.S. Department of Energy (DOE) set a goal of producing 60,000 megawatts of electricity from geothermal sources by 2050. Currently the country’s natural systems only generate about 2,500 megawatts, mostly from resources in California, Nevada and Utah.
The energy contained within natural geothermal resources is not sufficient to reach the 2050 goal. Although adequate heat can be found at depth, most subsurface rocks lack the water and permeability needed to form natural geothermal reservoirs. Studies show that even extracting a small percent of this energy from currently drillable depths would provide several thousand times the energy needed to power the U.S. for a year. To make this untapped resource a significant part of the nation’s renewable energy portfolio, and to make the DOE’s 2050 goal a reality, technologies must be developed for creating geothermal reservoirs where none exist naturally.
The Utah Frontier Observatory for Research in Geothermal Energy, or Utah FORGE, is a DOE-funded subsurface laboratory where new technologies and tools required for the creation of Enhanced Geothermal System (EGS) reservoirs can be tested. This laboratory, located near Milford in Beaver County is being built and managed by the University of Utah’s Energy & Geoscience Institute.
Formation of the geothermal reservoir will borrow tools and ideas being used by the oil and gas industry. The reservoir will be created by opening and connecting the tiny fractures that exist in the rock between two deep, highly deviated wells.
The first of these wells was successfully drilled in early 2021. The second parallel well will be drilled in late 2022. Together they will serve as the injection and production wells of this newly developed EGS reservoir. To serve the project and the environment, a state-of-the-art seismic monitoring system has also been installed to detect microearthquakes at magnitudes as low as -2, which cannot be felt by people.
Utah can play a vital role in the expansion of geothermal energy. Once achieved, the advances made in EGS research can be replicated nearly anywhere in the world providing a clean, constant and reliable energy source. It’s time we untap the heat beneath our feet.
Joseph Moore, Ph.D., serves as the managing principal investigator of Utah FORGE project. He holds appointments at the University of Utah as a research professor in the Department of Civil Engineering and Environmental Engineering and as an adjunct professor in the Department of Geology and Geophysics.