So far, we’ve been able to harvest only a tiny fraction of geothermal energy resources, taking advantage of places where local geology brings hot water and steam near the surface, such as in Iceland or California, where such phenomena have long been used to produce electricity. But new oil-field stimulation technology, developed for extracting oil from sources such as shale, makes it possible to harvest much more of this energy by allowing engineers to create artificial geothermal reservoirs?many kilometers underground.
Tester calls it?”universal geothermal” energy because the reservoirs could be located wherever they’re needed, such as near power-hungry cities worldwide. Technology Review spoke with Tester about the potential of universal geothermal energy and what it will take to make it a reality.
Technology Review: How much geothermal energy could be harvested?
Jefferson Tester: The figure for the whole world is on the order of 100 million exojoules or quads [a quad is one quadrillion BTUs]. This is the part that would be useable. We now use worldwide just over 400 exojoules per year. So you do the math, and you know you’ve got a very big source of energy. – more on techreview
The photo is from another geothermal idea: ground source heat pumps.