mirrors used in trough systems. A primary drawback of tower technology is the large investment required, with only large-scale plants making economic sense.
Dish concentrators (see Figure 5.12) are an emerging technology that functions on a principle similar to that of a solar tower but is scalable to smaller units. A reflective parabolic dish tracks the Sun and focuses onto a small power-conversion unit. A heat-transfer fluid is heated several hundred degrees Celsius and is subsequently
FIGURE 5.12 A dish solar thermal power generation module test unit in Phoenix, Arizona. The dish is approximately 75 feet in diameter. SOURCE: Courtesy of Southwest Solar Technologies.