Hot dry rock: What does it take to make it happen

The ubiquitous heat in hot dry rock (HDR) is an abundant, widely distributed form of geothermal energy. Until recently, development of this energy source has been largely focused on understanding the scientific and engineering principles involved in forming and operating HDR reservoirs. During the past year, however, a pilot facility at Fenton Hill, NM has been run under steady-state conditions simulating the operation of a commercial HDR energy plant. Issues important to commercialization such as sustainability of thermal production, water loss, operating costs, and others have been addressed to the extent possible. The results, while not always definitive, have been encouraging. The stage is now set for the formation of an initiative led by private industry to take HDR technology from its current state of scientific and engineering demonstration to the production and marketing of energy in commercial quantities. Because of the technology risks involved, this can probably only be accomplished through a cost-shared industry/government effort. The potential rewards are great, since HDR represents the best, and perhaps the only, opportunity for geothermal energy to take its rightful place as a major energy source for the 21st century.