During the 2008 elections, Americans have become locked in a debate over the best way to reach energy independence while minimizing our impact on the planet. This discussion quickly turned into a national security issue over the summer, as volatile energy markets and economic recession produced catch phrases such as "drill baby drill" and "Picken's Plan". While the merits and costs of alternative energy sources like wind and natural gas are debatable, there has been an absence of discussion over geothermal energy. So, what is geothermal energy and how does someone go about getting some?

Geothermal energy is heat trapped within the earth in the form of water. It is captured through three processes: district heating, electric generation and heat pumps.

First, district heating--as used in Reykjavik, Iceland--uses hot water found near the earth's surface and pipes it directly into buildings to provide radiant heat within large sections of a city; thus the term "district".

Second, electric generation uses water or steam at very high temperature to turn a turbine creating electricity in a process similar to those found in hydroelectric dams. Geothermal power plants of this type are generally built where geothermal reservoirs are located within a mile or two of the surface limiting their use to specific geographic regions.

Finally, heat pump systems rely on stable ground or water temperatures near the earth's surface to pump water into and out of the earth. Heat pump systems have the potential to become the most widespread form of geothermal energy because they are relatively easy to install.

While geothermal systems have their limitations, geographic and otherwise, all three processes have the potential to help America move towards domestic energy sustainability.