[Update: Lost in the press blitz about the Google.org investment was the fact that Altarock took $26.25 million in total. Advanced Technology Ventures, Khosla Ventures, Kleiner Perkins and Vulcan Capital all participated.] Here’s a fact: If you go outside, wherever you are, and start drilling a hole, once you get deep enough it will become very, very hot. Using that heat for electricity is the cornerstone of geothermal power, and it’s great if you can reach the hot spots — just ask Iceland. But much of that heat is difficult to reach or use, a detail that has inspired the latest investment by Google.org.