Figure 1. Schematic of an Enhanced Geothermal System. Shown are the injector and producer wells, and man-made fractures in the rock at depth between the wells. The injected fluid is pushed from injector to producer all the while picking up heat from the rock.

October 10, 2008:

The Washington Post last week had an interesting article about geothermal energy in the Philippines and beyond, featuring Stanford's Roland Horne. Roland can also be heard in an interview and a seminar on geothermal energy on this site.

Following up on his lecture on geothermal energy, Professor Roland Horne met with some of my students. Horne is an expert in extracting heat from the earth. Hear more about the engineering and science behind traditional geothermal energy, and the promising “hot dry rock” process.

In Iceland and a few other countries, geothermal energy delivers a large part of the energy used for heating or cooling, through geothermal heat pumps. You may be surprised to hear that there are hundreds of thousands of buildings in the U.S. that are also hooked up to such systems. Geothermal energy is also applied at larger scales for electricity generation in various countries. Roland Horne, who leads the geothermal institute at Stanford University, gives an overview of existing and future geothermal energy systems. In future podcasts, we’ll take a closer look at the interesting Enhanced Geothermal Systems, aka Hot Dry Rock, which Roland discusses as a potentially important future energy source.