Energy Technologies: How They Work and Their Induced Seismicity Potential - Induced Seismicity Potential in Energy Technologies - page 38

The most likely regions for commercial development of geothermal power are gener-
ally the same regions that have experienced recent volcanism (Figure 3.1). Such areas are
concentrated in the western portion of the country. The U.S. Geological Survey (USGS)
estimates that the total power output from the hydrothermal (vapor- and liquid-dominated)
geothermal resources in the United States can probably be increased to 3,700 MWe per
year, and a 50 percent probability exists that it can be increased to about 9,000 MWe per year
(Williams et al., 2008). Two recent studies have produced nationwide estimates of the
electric power potential that might be achieved by a successful implementation of enhanced
geothermal systems (EGS) technology, perhaps contributing 100,000 MWe of electrical
power per year (MIT, 2006). More recently the USGS (Williams et al., 2008) has published
a mean estimate for potential EGS development on private and accessible public land at

The Geysers

Coso Geothermal
Field

Heat Flow (mW/m )

2
25-29 30-34 35-39 40-44

45-49 50-54 55-59 60-64 65-69 70-74 75-79 80-84 85-89 90-94 95-99 100-149 150+

FIGURE 3.1 The location of the geothermal provinces in the United States. Within the United States the
regions of relatively high thermal gradients, shown in red, exist only in the West. The typical local geologic
setting for these high-geothermal-gradient areas is within sedimentary basins located near or intruded by
recent volcanics, or within (as part of) the buried volcanic rocks themselves. Only one vapor-dominated
reservoir has been developed in the United States (The Geysers); the remainder of the areas in red and
orange may host viable liquid-dominated or enhanced geothermal system reservoirs. SOURCE: SMU
Geothermal Lab; Blackwell and Richards (2004).