A User's Manual for DELSOL3 - prod.sandia.gov - Sandia National ...

Receiver System Efficiency: The ratio of the thermal power absorbed by
the receiver working fluid and delivered to the base of the tower to the solar radi-
ant power delivered to the receiver under reference conditions.
Reflectance: The ratio of the reflected radiant flux to the incident radiant
flux on a surface. For a solar thermal system, the specular reflectance is of inter-
est.
Repowering: The retrofitting of existing fossil-fueled utility or process heat
power plants with solar energy systems in order to displace a portion or all of the
fossil fuel normally used.
Riser: The pipe carrying the cold heat transport fluid up the receiver tower.
Shadowing or Shading: The shading of the reflective surface of one helio-
stat from the sun’s rays by another heliostat.
Smart Aiming: An aiming strategy of heliostats in which aimpoints on the
receiver are spread out to reduce peak flux levels. This usually refers to the op-
tion IAUTOP=l for external receivers and IAUTOP=3 for cavity or flat plate
receivers.
Smart Optimization: The process in DELSOL of finding the optimum sys-
tem based on levelized energy cost, where not every possible combination of re-
ceiver and tower dimensions allowed by the user will be examined. Instead, DEL-
SOL will assume that each variable has a single minima which is not affected by
other variables and that all dimensions tend to increase as the power level in-
creases. Also, if a receiver power cannot be obtained for a given tower height for
any size receiver, no further systems will be examined for that tower height. This
option, which is controlled by the input variable IALL, is used as a method of re-
ducing computer execution time during system optimization.
Solar Multiple: The ratio of the thermal power that is absorbed in the re-
ceiver fluid and delivered to the base of the tower at the system design point to
the peak thermal power required by the turbine-generator (or other end use).
Solar Noon: See Solar Time.
Solar One: See Ten Megawatt Electric (10 MWe) Solar Thermal
Central Receiver Pilot Plant.
Solar Thermal Central Receiver System: A solar power system which
concentrates the available solar energy by means of an array of computer con-
trolled heliostats to a tower-mounted receiver. The energy absorbed at the re-
ceiver is removed as thermal energy in a working fluid.
Solar Time: The time as reckoned by the apparent position of the sun. So-
lar noon occurs when the sun reaches its zenith.
Specular: Having the qualities of a mirror which reflects with no scattering.
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