books.google.com - Geothermal energy is produced by heat deep inside Earth, and we can use it to power machines, as well as to heat our homes, schools, and offices. How do we harness geothermal power? Will it ever run out? Can it provide us with the energy we need in our power-hungry world? Book jacket....http://books.google.com/books/about/Geothermal_Power.html?id=_0ayqSIO0OgC&utm_source=gb-gplus-shareGeothermal Power
