A Few Things Ill Considered

I know I am a bit late on this one, but CBC Radio's "Quirks and Quarks" had a very interesting segment on geothermal energy February 2. You can listen to the segment directly here.

The page for that day's show is here, where you can read the following teaser and find links to related material:

We're familiar with geothermal energy from mountain hot springs, geysers like Old Faithful in Yellowstone Park, and perhaps from the way Iceland has developed an entire energy system based on volcanic-heated water. However, geothermal energy is still just a niche player in the global energy picture. But that may be changing. Currently, we generate geothermal electricity from places where heat from the Earth's core runs into underground water, which can produce high temperature steam, but these sites are rare. Dr Alan Jessop, who worked for Natural Resources Canada and led the geothermal energy program there, surveyed Canada's resources, but there were relatively few promising natural sites. Several nations, however, are working on new technology to create artificial geothermal reservoirs. These are enhanced geothermal systems in which deep holes are bored and water is pumped in to generate a source of very hot water. Dr. Jeff Tester, a professor of Chemical Engineering at the Massachusetts Institute of Technology, and Dr. Michal Moore, a Senior Fellow in the Institute for Sustainable Energy, Environment and Economy at the University of Calgary, helped prepare a report on the potential of enhanced geothermal energy. They think that up to ten percent of the US's electricity could be generated this way in the next fifty years - some 100,000 Megawatts.

Extremely hot rock isn't the only way to use geothermal energy, though. You can also get energy from relatively cool ground using a technology called geo-exchange. Currently, thousands of Canadian homes are heated this way using devices called ground-source heat pumps. Gary Poyntz, the Vice President of Clean Energy Developments (CED) in Toronto, installs these systems to replace heating and cooling systems, at an energy savings of 75% or better. Mark Douglas, an engineer at Natural Resources Canada, says that the systems run by extracting the small amount of energy from water circulated through a loop usually buried in the ground, and using that energy to heat the home. Paul Mertes, the President of CED, expects his business to grow immensely in the next few years, as the financial, energy and carbon emission savings from geo-exchange are very large.