Simulation of Utility-Scale Central Receiver System Power Plants

The operation of solar energy systems is necessarily transient. Over the lifetime of a concentrating solar power plant, the system operates at design conditions only occasionally, with the bulk of operation occurring under part-load conditions depending on solar resource availability. Credible economic analyses of solar-electric systems requires versatile models capable of predicting system performance at both design and off-design conditions. This paper introduces new and adapted simulation tools for power tower systems including models for the heliostat field, central receiver, and the power cycle. The design process for solar power tower systems differs from that for other concentrating solar power (CSP) technologies such as the parabolic trough or parabolic dish systems that are nearly modular in their design. The design of an optimum power tower system requires a determination of the heliostat field layout and receiver geometry that results in the greatest long-term energy collection per unit cost. Research presented in this paper makes use of the DELSOL3 code (Kistler, 1986) which provides this capability. An interface program called PTGEN was developed to simplify the combined use of DELSOL3 and TRNSYS. The final product integrates the optimization tool with the detailed component models to provide a comprehensive modeling tool set for the power tower technology.