Geothermal energy is heat taken from below the surface of the earth in the form of either steam or hot water. This energy can be used to generate electricity, but also has use in heating and cooling homes and some direct uses, such as gold mining, food dehydration, and milk pasteurizing. There are four basic types of geothermal power plants including steam, flash, binary, and enhanced geothermal system (EGS). The first three rely on permeable aquifers that have water flowing through them such that hot water or steam can be extracted. EGS, however, extracts heat from deep in the earth by injecting water and creating artificial fractures in the rock. A great deal of the world’s potential for geothermal energy exists in the so-called Ring of Fire, a ring of volcanoes around the Pacific Ocean.
Progress on Heat Transfer in Fractures of Hot Dry Rock Enhanced Geothermal System
