Unlike traditional geothermal sites, EGS doesn’t rely on natural hot water reservoirs—it creates engineered systems where fluid is injected into hot rock, extracting heat in a controlled loop. While promising, long-term reliability remains an open question. The key challenge: ensuring that these engineered reservoirs stay open and efficient for decades. Over time, underground fractures can clog with minerals, limiting heat transfer and reducing energy output. These are the questions CUSSP is aiming to answer.
The demand for scalable, clean energy has grown sharply as sectors like cloud computing, manufacturing, and logistics look to decarbonize. Tech companies in particular have taken early interest: Google, in partnership with startup Fervo Energy, opened the first operational EGS power plant in the U.S. in 2023. But for most businesses, geothermal remains a long-term bet—one that still carries technical and financial risk.
That’s where the controlled environment of SURF becomes a key differentiator. By controlling variables such as rock type, water chemistry, and flow rate, researchers can study underground heat exchange processes with greater accuracy than field experiments allow. New sensor arrays and high-volume data collection allow the team to correlate geophysical signals—like seismic data or electrical resistivity—with chemical processes happening in real time underground.
PNNL earth scientist Jeff Burghardt notes that remotely monitoring subsurface chemistry remains a major challenge. However, if researchers can consistently link surface signals to underground activity, it could significantly improve how geothermal plants are operated and maintained.
SURF is also playing a role in building the future geothermal workforce. Dozens of undergraduate, graduate, and postdoctoral researchers are contributing to the CUSSP effort. Their work blends geoscience, mechanical engineering, and data modeling—skillsets that will be essential as more businesses explore geothermal as part of their energy transition strategies.
Similar geothermal initiatives are underway at DOE test sites across the U.S. But the precision and data coming from SURF are helping businesses, policymakers, and investors make more informed decisions about geothermal’s role in the energy mix.
