27 May 2025
Approximately 80% of our nation’s energy comes from deep belowground in Earth’s subsurface, an environment Berkeley Lab scientists have been studying for almost five decades. Partnering with industry and academia, their goal is to enable more effective and informed use of underground resources — from fossil fuels to geothermal energy to water.
Berkeley Lab’s researchers are advancing the science needed to access underground energy sources and store energy underground. They’ve made big advances in estimating lithium reserves and mapping rare earth elements, and are inventing new ways to measure earthquake risks to infrastructure and track groundwater. Read on to learn how Berkeley Lab is refining our understanding of the subsurface environment.
Geothermal Energy
Berkeley Lab geoscientists are advancing enhanced geothermal systems (EGS) — engineered reservoirs in Earth’s subsurface capable of providing access to round-the-clock energy. EGS technologies stimulate the flow of fluids through hot rocks that can be converted to electricity at the surface. Geothermal electricity-generating capacity has the potential to expand 20-fold in the United States by 2050 — enough to power up to 65 million homes.
With nearly 50 years of geothermal research behind them, geoscientists at Berkeley Lab study which geologic factors, such as depth and rock type, are most favorable for developing geothermal reservoirs. They led the U.S. Department of Energy-funded EGS Collab project, which focused on developing technologies to model and monitor rock fracturing at depths greater than two kilometers and temperatures exceeding 200°C. Now, they are testing methods to create and sustain EGS at Utah FORGE, a field-scale lab, and through other DOE-supported demonstration projects, including one exploring superhot conditions above 700°F. These can provide significantly more energy compared to geothermal reservoirs with lower temperatures.
Critical Minerals and Materials
The U.S. relies heavily on imports for critical minerals such as lithium, a key battery metal. With demand for some of these critical minerals expected to increase by up to seven times by 2030, Berkeley Lab scientists are finding new ways to tap into domestic resources and develop technologies for efficient mineral recovery. They use state-of-the-art tools to better understand how mineral systems form, evolve, and are transformed into important functional materials. Their research integrates fieldwork, laboratory experiments, and modeling to explore sources such as lithium in geothermal fluids and claystones, rare earth elements in mine tailings, and cobalt and cadmium in geological rock formations.
In a major step toward securing minerals domestically, Berkeley Lab scientists conducted the most comprehensive analysis yet of lithium reserves found in geothermal brines from Southern California’s Salton Sea. Their findings indicate the region could contain over 3,400 kilotons of lithium — enough to produce more than 375 million electric vehicle (EV) batteries, surpassing the total number of vehicles currently on U.S. roads.
AI and machine learning play a key role in characterizing and processing these critical minerals. The team is also mapping rare earth elements — like neodymium, used in high-performance magnets for energy and medical applications — from industrial waste such as coal fly ash. By combining drone-based geophysical sensing with AI, they are pinpointing neodymium hotspots at fly ash sites in Pennsylvania and developing processes to efficiently transform them into magnets.
Seismic Risk and Impact
Berkeley Lab researchers study seismic activity through real-world measurements and high-performance computing to predict major quakes and understand earthquake impacts on groundwater. Using the Perlmutter supercomputer at the National Energy Research Scientific Computing Center (NERSC), located at Berkeley Lab, they create high-frequency ground shaking simulations to identify the infrastructure within a region most at risk of a severe quake. This large database of simulated ground motions for the San Francisco Bay Area, shared with engineers via an open-access database, related to a M7 Hayward fault earthquake and is being replicated in the Los Angeles region and in a region of the Midwest that has experienced large quakes. This work is progressing in partnership with the Pacific Earthquake Engineering Research Center at UC Berkeley and with the University of California at Los Angeles. With partners at the University of Nevada-Reno, the researchers also developed the largest U.S. facility for studying how the soil around a structure influences building performance during quakes.
Another team deployed an ultra-sensitive sensor developed at Berkeley Lab’s Geosciences Measurement Facility into a 200-meter-long borehole along the San Andreas Fault to measure natural seismicity from earthquakes. An example of what the future of earthquake data collection could look like, these instruments capture in real-time the displacement, location, and any changes in water pressure associated with faults — representing the first time that datasets can be sourced from a singular, continuous, autonomous sensor. This can give unprecedented insights into important societal and environmental implications from seismic activity, such as water-level shifts.
Energy Generation and Storage
Building on their expertise in fluid behavior in underground rock from geothermal energy research, Berkeley Lab scientists are exploring ways to ensure year-round energy access through geologic hydrogen and underground water-storage systems. With support from DOE’s ARPA-E program, they conduct research essential to stimulating the production of geologic hydrogen through chemical reactions between certain rocks and water in the subsurface, and to extracting geologic hydrogen safely. Applying knowledge gained over several decades of observing how fluids behave in Earth’s subsurface, one team is studying how to inject fluids at varying pressures, temperatures, and pH levels to control the extraction of hydrogen without inducing harmful seismicity.
Geologic hydrogen generation occurs fastest in deep and hot environments that would be costly and commercially risky to access. Berkeley Lab researchers are using quantum chemistry simulations and experiments as they investigate how to speed up hydrogen-generating reactions in cooler, shallower environments safely and affordably.
In parallel, scientists are advancing aquifer thermal energy storage (ATES), which uses naturally occurring underground water to store energy for later use to heat and cool buildings — helping reduce power grid strain during extreme temperatures. These systems use deeper aquifers that don’t impact drinking water supplies and often rely on heat pumps to deliver energy at usable temperatures.
Water Management and Reuse
Approximately 40% of the U.S. water supply comes from underground reserves, but their location, volume, and availability are often uncertain. To better understand and manage these resources, Berkeley Lab geophysicists track water movement using a mix of traditional methods, new sensors, and modeling tools. Their work helps answer key questions about groundwater recharge — such as where water goes, whether it reaches the aquifer, and how subsurface geology affects recharge. They’ve developed a way to estimate aquifer volume changes by analyzing ground deformation with satellite images and advanced modeling, creating region-specific 3D groundwater maps.
A suite of software codes developed at Berkeley Lab, called TOUGH for Transport of Unsaturated Groundwater and Heat, helps solve complex problems requiring advanced simulation of the movement of fluids and heat in Earth’s subsurface. Originally developed to trace groundwater contamination, the TOUGH codes are now widely used in research and industry for applications like geothermal energy and oil and gas production.
Berkeley Lab also leads efforts through the National Alliance for Water Innovation (NAWI) to improve desalination technologies for treating groundwater and other salty waters. Supported by the DOE and several California agencies, NAWI aims to lower the cost and energy demands of using nontraditional water sources.
[Image]
(A) Berkeley Lab scientists are quantifying lithium and studying its recovery from the brines deep beneath the Salton Sea.
(B) Berkeley Lab researchers conduct a drone survey for rare earth elements at a coal refuse site in Pennsylvania.
(C) A scientist in the field sets up fiber optic sensing cables to monitor seismicity underground along the San Andreas fault.