“EGS offers important opportunities for increasing the contribution of geothermal energy to U.S. power production: by a few-fold over the next few years, according to our estimation, and much more so if this initial success is appropriately leveraged over subsequent years,” the report concluded.
As described in the report, EGS entails drilling deep into the Earth’s crust — 1 to 5 kilometers or more — and forcing a fluid (water or brine) through hot, permeable rock. Energy from the heated fluid can then be extracted.
Of course, the technology is not without hazards. One is the potential for pollution of potable water acquifers. Another more ominous concern is “induced seismicity” — or artificially-generated earthquakes.
“Induced seismicity is a relatively well-documented phenomenon associated with changing fluid pressures at depth,” the report notes. The JASONs assert that “there is a basis for controlling the induced seismicity and therefore for minimizing this potential hazard attributable to EGS.”
The new JASON report is elegantly written and can be at least partially understood by non-specialist readers who may have forgotten their heat and mass transfer equations. A copy was obtained by Secrecy News.
Over the past year, the JASONs completed eight classified studies containing sensitive compartmented information (SCI) that have not been disclosed. Several other unclassified reports were also performed and their release is pending.
In 2012, the Central Intelligence Agency refused to release a JASON report entitled “Metamaterials.”
Update: For more background on enhanced geothermal systems, see this story in Scientific American.