Key Takeaways
- Geothermal power plants can operate at maximum capacity nearly 24/7/365 because the Earth's heat is constantly available.
- There is a substantial amount of heat in subsurface rock essentially everywhere, but not all rock is permeable enough to allow fluid to flow through. By enhancing rock permeability, enhanced geothermal systems (EGS) technologies help improve access to this near-ubiquitous domestic source of 24/7/365 energy.
- The U.S. has an advantage to expand EGS because our substantial infrastructure and technology for oil and gas production is the basis of what's needed to expand geothermal energy to more places around the country using EGS and other next-generation geothermal technologies.
With its capacity to provide 24/7 power, many are warming up to the prospect of geothermal energy. Fluids flowing through hot rocks deep underground absorb heat, which can be brought to Earth's surface to generate steam that powers turbines and produces electricity. Geothermal electricity-generating capacity has the potential to expand 20-fold in the United States by 2050. In the United States, where decades of experience in unconventional oil and gas production can be applied to new geothermal technologies, geothermal energy could power the equivalent of 65 million homes by 2050.
Eva Schill, Berkeley Lab Staff Scientist and Geothermal Systems Program Lead (Credit: Thor Swift/Berkeley Lab)
Scientists are currently working to advance humanmade reservoirs in Earth's deep subsurface to stimulate the activity that exists within natural geothermal systems. EGS technologies have the potential to be expanded throughout the country, in both the western United States where geothermal conditions are optimal, and the eastern U.S., where accessing temperatures hot enough for geothermal electricity production or thermal production requires deeper drilling.
Eva Schill, Berkeley Lab Staff Scientist and Geothermal Systems Program Lead, shared insights on how EGS technologies could provide affordable domestic geothermal energy and what Berkeley Lab scientists in the Energy Geosciences Division are doing to advance this field.
"The U.S. has a great advantage to expand EGS, because the technology can be based on the experience of the country's extensive unconventional oil and gas production that can be transferred to geothermal engineering."
- Eva Schill
Q. Why is geothermal in particular a promising domestic energy source for the United States?
Geothermal power plants can operate at maximum capacity nearly 24/7/365 because the Earth's heat is constantly available. To a certain extent, geothermal power plants can also respond to changing electricity demand by increasing or lowering energy generation, offering flexible production. We can even store large capacities of excess energy, for example in depleted underground reservoirs once used for oil and gas extraction, to save or use at a time of particularly high energy demand.
The U.S. has a great advantage to expand EGS, because the technology can be based on the experience of the country's extensive unconventional oil and gas production that can be transferred to geothermal engineering. In a recently published Nature Reviews Clean Technology paper, my colleagues and I discuss how adopting oilfield drilling strategies has made EGS drilling easier and less expensive.
Geothermal power plants also bring hot liquids rich in critical minerals to Earth's surface, offering access to elements such as lithium, a key ingredient in most batteries.
