On the BBC News Science and Environment web pages, there is an interesting article on large heat pumps using geothermal energy. The article is available here.
A web page on Geothermal energy in Slovenia published by Geološki zavod Slovenije (Slovenian Geological Survey) is available here. A Geothermal map of Slovenia (in grade Celsius at 1000 m depth) is shown above. The Slovenian Geological Survey is a member of the European Geothermal Energy Council. More on renewable energy can be read on web pages of the International Renewable Energy Agency.