Everywhere on Earth, a few miles below the surface, the bedrock is hot, and the deeper you go the hotter it gets. In some places, water heated by this hot rock comes naturally to the surface or close to it, where it can be easily tapped to drive a turbine and generate electricity.
We're familiar with geothermal to heat homes and buildings, but industrial scale geothermal carries with it concerns about earthquakes being caused by disrupting large systems that we aren't totally familiar with.
Research is underway in the alternative energy pursuit for cleaner, less climate changing methods of powering our insatiable hunger for air conditioning and electrical gadgets.
But where naturally heated water is not available at or near the
surface, this process can be recreated by drilling one very deep well
to inject water into the ground, and another well nearby to pump that
water back to the surface after it has been heated by passing through
cracks in the hot rock.
Such systems are known as Engineered Geothermal Systems, or EGS.
Grants recently awarded to MIT researchers by the U.S. Department of Energy (DoE) could help to pave the way for a method of generating electricity that produces no greenhouse gas emissions, and that could become a major contributor to meeting the world's energy needs.Most energy analysts agree that geothermal energy -- tapping the heat of bedrock deep underground to generate electricity -- has enormous potential because it is available all the time, almost anywhere on Earth, and there is enough of it available, in theory, to supply all of the world's energy needs for many centuries.
But there are still some unanswered questions about it that require further research. DoE last year awarded $336 million in grants to help resolve the remaining uncertainties, and three of those grants, totaling more than $2 million, went to MIT researchers.
A 2006 report by an 18-member team led by MIT Professor Jefferson Tester (now emeritus, and working at Cornell University) found that more than 2,000 times the total annual energy use of the United States could be supplied, using existing technology, from EGS systems, and perhaps 10 times as much with improved technology.