The GEA is the trade association for the geothermal energy industry. Their website http://www.geo-energy.org/ http://www.geo-energy.org/ has a 72-page booklet w

The GEA is the trade association for the geothermal energy industry. Their website http://www.geo-energy.org/ http://www.geo-energy.org/ has a 72-page booklet with a lot of info including details on how a geothermal plant works (pp. 9-16) and a comparison of the capitalized cost of geothermal energy per megawatt hour compared to other energy resources (p. 58). See http://geo-energy.org/reports/Gea-GeothermalBasicsQandA-Sept2012_final.pdf http://geo-energy.org/reports/Gea-GeothermalBasicsQandA-Sept... [pdf] I'm a big fan of 2000AD and Judge Dredd comics. Mega-City One is powered by geothermal energy. A description of the "Power Tower" appears in prog #122, "Judge Dredd: Father Earth, Part 1": "Power Tower is Mega-City One's southern electricity generating complex. It is built around a di-crystal central bore hole that descends one hundred miles into the Earth's crust tapping power from the planet's molten core." Source: http://dreddalert.blogspot.com/2013/12/judge-dredd-father-earth-part-1.html http://dreddalert.blogspot.com/2013/12/judge-dredd-father-ea... So MC-1's fictional bore hole descends about 40 times deeper than the real one in Iceland described in this article.