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CONCENTRATOR SOLAR TECHNOLOGIES 235
Emission reduction Emissions benefits of CSP technologies depend on many
factors, including whether they have their own storage capacity or are hybridized with
other electricity- or heat-producing technologies. CSP technologies with storage produce
zero emissions, and hybrid technologies can reduce emissions by 50 percent or more.
PASSIVE PARABOLIC HEATING TECHNOLOGIES
In this technology, a large field of parabolic systems that are secured on a single-axis
solar-tracking support is installed in a modular parallel-row configuration aligned in a
north-south horizontal direction. Each of the solar parabolic collectors tracks the
movement of the sun from east to west during daytime hours and focuses the sun’s
rays to linear receiver tubing that circulates a heat-transfer fluid (HTF). The HTF, in
turn, passes through a series of heat-exchanger chambers where the heat is transferred
as superheated vapor that drives steam turbines. After propelling the turbine, the spent
steam is condensed and returned to the heat exchanger via condensate pumps. Figure 6.9
is a photograph of a parabolic heater installation.
At present, the technology has been applied successfully in thermal electric power–
generation. A 354-MW solar electric power–generation plant installed in 1984 in the
California Mojave Desert has been in operation with remarkable success.
SOLAR TOWER TECHNOLOGIES
Another use of CSP technology that generates electric power from the sun is a con-
struction that focuses concentrated solar radiation on a tower-mounted heat exchanger.
The system is basically configured from thousands of sun-tracking mirrors, commonly
Figure 6.9 Passive parabolic concentrator installation. Courtesy of Solargenix.