2.2. Process modelling and economics
Fig. 2 depicts the overall methodology employed in this study.
The elements of the methodology used in this study are elaborated
in the succeeding tables and equations discussed in this section.
Table 1 presents the typical dimensions and thermodynamic
outputs of the commercially available CSP parabolic troughs for
electricity production, and the methodology used to derive the values
in Table 1 is now discussed.
The value of DNI (Direct Normal Irradiance, ie direct sunlight) of
750 W/m2 is a conservative number, representative of locations
with high concentrations of direct sunlight on an average basis
(e.g. desert regions of North Africa, the Middle East, and the
Americas) or peak levels of direct insolation in more temperate
latitudes. For reference, DNI at the top of the earth’s atmosphere
(the so-called ‘‘Solar Constant”) is approximately 1380 W/m2).
Table 1 also includes optical and thermal loss values from a