Steam rises from the Calpine steam power plants located on a ridge at The Geysers on April 28, 2014, near Healdsburg, California. | George Rose/Getty Images
Energy

Next-Gen Geothermal Could Unlock Vast Energy Supplies Just Below Earth’s Surface

Earth’s upper crust holds 50,000 times more energy than all of the world’s oil and gas combined, and US researchers are figuring out how to utilize that potential energy source.

Published On 08/16/2017
4:49 PM EDT
I I n the Mayacamas Mountains 70 miles north of San Francisco sits a power facility that literally turns toilet flushes into clean energy. The system, known as the Geysers, takes in 20 million gallons of filtered wastewater a day from the local community. That water is pumped deep underground through fissures in blazing hot rock, then sucked back to the surface as steam to run power generators.
‘You have to find hot rock, fluids in place, and the ability to flow through the rock.’
Berkeley Lab scientist Tim Kneafsey demonstrates how he places rock samples, from the Brady Geothermal Field in Nevada, into a stress permeability apparatus, which tests how long a fracture can remain open. | Marilyn Chung/Berkeley Lab