Excellent write-up on EGS
Again, from Renewable Energy Access: (these folks are on a roll today…)
A report prepared by the Massachusetts Institute of Technology (MIT) considers the immense potential from Enhanced Geothermal Systems (EGS), sometimes referred to as Engineered Geothermal Systems. The MIT report, called “The Future of Geothermal Energy – Impact of Enhanced Geothermal Systems (EGS) on the United States in the 21st Century,” was released in January 2007…
…As you probably know, geothermal power plants have been producing electricity for many years. Conventional geothermal power plants make use of underground steam or hot water and are known as “hydrothermal” systems. In order for hydrothermal systems to work, they must have: (1) high enough temperatures; (2) water or steam saturation of the field; and (3) good permeability. Rocks are permeable due to minute fractures and pore spaces between mineral grains.
With EGS technology, heat is extracted by fracturing rocks underground to make the subsurface more permeable. After the fracturing process, water is added to the system through injection wells. Injected water is heated by contact with the rock and returns to the surface through production wells, as in naturally occurring hydrothermal systems. With an EGS system, the three critical factors listed above (temperature, water, and permeability), are not essential. Even if the water isn’t present or the rock structure isn’t sufficiently permeable, the systems can be “engineered” by manually fracturing the rocks and adding water…
…So how can the U.S. become a leader in EGS development? First, the White House should reinstate funding for the Department of Energy’s Geothermal Technologies program, which has been zeroed out for the second year in a row.
Second, the program should be funded at the level needed to advance geothermal technology development. According to the MIT study, a modest investment in EGS over fifteen years — $800 million to $1 billion — would be sufficient to develop EGS potential. That’s roughly what the Bush Administration proposes to spend on fusion energy research in just two years, or less than one-half of the expected cost of one next generation nuclear power plant, as estimated by another MIT study…
After seeing the cooperation other governments are providing in the renewable energy space, it would be a good idea for the US to step up to the plate around this and other opportunities.
