Topic 27: Geothermal Energy a clean, safe, environmentally friendly and sustainable energy source
(http://www.renewableenergyworld.com/rea/tech/geothermal-energy) This is a very clean, environmentally friendly and sustainable energy source. It is the heat from the earth crust. The heart of the earth is about 12000 degrees farenheit. Geothermal systems tap into this inexhaustive though not generally available energy source. Example is Reykjavik the capital of Iceland which islocated near hot springs.