Deep Geothermal Energy
See these links for more information on deep geothermal energy:
http://e360.yale.edu/content/feature.msp?id=2077
http://dtenergy.org/index.php?id=276
http://dtenergy.org/fileadmin/dateiliste/Dokumente/DTE_Engineering/Medienberichte/St.Tagblatt_24.03.2011.pdf