Enjoyed the conversation yesterday with the Antioch College president about their commitment to green energy - specifically "geothermal" energy for heating and cooling the buildings on their campus in Yellow Springs, Ohio.
Unfortunately the term "geothermal" is used in several confusing contexts and Mark Roosevelt and Mr. Hartmann were using two different concepts. Thom was thinking about the thermal energy and extreme temperatures associated with the molten core of the Earth that we can tap into (often at extreme depths) to create steam to drive turbines to produce electrical power or heat buildings as indicated by the graphics displayed prior to the interview. That's not the energy concept being used by Antioch. Unfortunately "geothermal" is also used to refer to "geoexchange" or "ground source" energy systems that Mr. Roosevelt was describing. This use of "geothermal" refers to the thermal energy of the ground (just below the frost line ) that remains at relatively constant temperature year round (50-60 degree F in the lower 48) that can be used to moderate the temperatures of our buildings with the help of a heat pump (same technology as that used in a refrigerator). So in the summer when the air temperature rises to 100 degrees and your building warms, the heat pump transfers excess heat into the 55 degree ground. But in the winter when the air temperature is -15 degrees, the heat pump will pull thermal energy from the ground to heat the building. The heat pump is powered by electricity harvested from the Sun. No burning of ancient hydrocarbons is required. See the DOE website for details. http://energy.gov/energysaver/articles/geothermal-heat-pumps
I personally can verify this version of "geothermal/geoexchange" technology works. We transitioned our home from burning to harvesting sunlight in 2010. We added 40 solar PV modules on our roof and now produce our own power from the Sun. We replaced our natural gas furnace with a geothermal/geoexchange heat pump furnace. There is no burning in our home. Our energy needs are now provided by the Sun - not just for our home, but also the Sun provides the energy for us to drive a plug-in hybrid (Chevy Volt) about 10,000 miles a year with zero emissions.
Thanks for the Green Energy information - and your discussions about how we can repair our broken economic system, by internalizing externalities ( ignored costs) associated with the "burning industry." Implementing a Pigovian Correction in the form of a market-based revenue-neutral carbon burning fee-dividend program seems like an excellent approach. For example, we can correct the market price of tar sands oil products by tacking on a Pigovian Correction as the Keystone XL oil flows across the Canada-U.S. border. By having the extractor pay a carbon burning fee that covers the Reparation Costs (to re-sequester CO2) and the Replacement Cost (to replace an equivalent amount of energy by harvesting energy from inexhaustible sources (solar, wind, hydro...) so this energy is put back into the Earth's energy bank for future generations), the market price of this oil will increase by over $200/barrel. Having eliminated two externalities and corrected the market, then let the free market decide.