Inquiring Minds
9:24 am
Wed December 1, 2010

Inquiring Minds - Geothermal Energy

Phoenix, AZ – This is Inquiring Minds insights from the campus of Northern Arizona University.

There are about 600 geologically young volcanoes in northern Arizona's volcanic field. They stretch from Williams to Grand Falls. The youngest are those farthest to the east.

Wendell Duffield has been studying these and other volcanic areas for more than 40 years. During one of his early projects, he helped assess the geothermal-energy potential of the Coso (CO-SO) Volcanic Field in southern California. Geothermal steam there now generates enough electricity for a city of about 250,000 people.

Geothermal power is tapped by drilling into very hot water or steam in the Earth's crust. Steam from the wells then drives a turbine to generate electricity. The intense heat comes from the roots of young volcanoes.

Some of northern Arizona's volcanoes are good candidates for such energy production, because they are no more than a few thousand years old. Simply put, the younger a volcano, the greater the likelihood that its magmatic roots will still be hot enough to create a resource of high pressure geothermal steam.

Northern Arizona's volcanic field doesn't have any hot springs, which scientists use to determine how hot the steam is below the surface. This probably has discouraged energy companies from drilling test wells. But as the need for new energy resources increases, power companies may look to northern Arizona.

Along with NAU professors Nancy Riggs and Michael Ort, Duffield continues to study the world's volcanoes, with an eye to those in our backyard and the renewable energy they might one day produce.

Inquiring Minds is a production of KNAU, Arizona Public Radio. I'm Bonnie Stevens.