Abstract :
The heliostat field layout is an essential task for any solar tower plant optimization process. Radially staggered and
other distributions are usually optimised by computer codes using different approaches. In most of those cases, due to
the CPU time required, the heliostat field layout is optimised by several mathematical models and simplifications. With
today s computers, it is possible to calculate the yearly energy available at any point in a site for a given tower height,
the yearly normalized energy surface (YNES). Yearly efficiency maps can be generated based on the cosine factor, the
spillage factor and the atmospheric attenuation coefficient of the site using real Direct Normal Irradiance (DNI) data,
within a reasonable computing time. It is therefore easy to find the place where the yearly energy available is the highest
for location of the first heliostat. It is also possible to calculate the effect of shadowing and blocking by this heliostat on
the YNES, so YNES can be re-calculated and the best position for the next heliostat can be found. Although this iterative
method is time-consuming, it is worthwhile if either the efficiency of the solar plant can be increased or the capital
cost reduced. This YNES-based layout generation method enables better flexibility than pre-determined gridding strategies
such as used in DELSOL. The paper includes a description of the optimization procedure.
2005 Elsevier Ltd. All rights reserved
