ADAPTIVE HELIOSTAT SOLAR ARRAYS USING SHAPE-OPTIMIZED COMPLIANT MIRRORS

In a Solar Power Tower (SPT) system, the ideal shape of a heliostat concentrator is a section of paraboloid which is a function of the location in the array and the incidence sun angle. This shape is difficult to achieve and limits the system efficiency. A shape-optimized compliant (SOC) design of parabolic heliostats is presented here to solve this problem. An approximation of the ideal shape is suggested to use an optimized stationary paraboloid shape which only varies with heliostat location in the array. A compliant structure design is proposed that to use a simple flat mirror with a two-dimensional tailored stiffness profile to form the required parabolic surface using adjustment mechanisms at each corner. This design is validated by numerical simulations including FEA tools, ray tracing, and classical nonlinear optimization. The annual performance shows that the SOC heliostat will substantially improve the efficiency and benefit the SPT system