Extracting Heat From the Earth to Generate Sustainable Power
In a small town in northwestern Nevada, America’s first commercial, grid-connected enhanced geothermal system (EGS) is up and running.
The new 1.7 megawatt “Desert Peak 2” EGS installation, harnesses the boundless supply of heat found thousands of feet below the earth’s surface to generate clean, renewable electricity. The project is being led by Ormat Technologies.
While a largely untapped resource, EGS could play a critical role in America’s energy future. Whereas traditional geothermal systems are largely limited to deployment in the western United States, EGS can be deployed all across America – extending geothermal’s overall reach. Geologists estimate EGS can supply more than 100 GW in the U.S. alone — a 40-fold increase over present geothermal power capacity.
To deploy EGS, production wells are drilled to depths of 10,000 feet and beyond to access the hot rock that makes up the earth’s crust. Under carefully controlled conditions, pressurized water is injected into the wells to open pre-existing fractures along the surface of the rock – creating permeability. This increased permeability allows the water to flow through the openings in the rock – capturing the rock’s heat. The heated water is then pumped back to the surface and the resulting steam is used to power a turbine to generate electricity. The water is cooled back into a liquid and injected back into the ground to repeat the cycle again in a closed loop system. Learn more about the process by taking a look at our new Geothermal 101 Infographic.
To generate electricity, the Desert Peak EGS project utilizes a production well at a previously built geothermal site in Churchill County. Since beginning production, the project has increased power output at the site by nearly 38 percent.