Variable Density Heliostat Field Layout

Abstract

A heliostat array having a variable field density for use in a concentrating solar power (CSP) plant. Heliostats are arranged into subgroups and configured to track the sun and reflect light to a receiver tower. Heliostats are deployed onto structures, wherein the structures can be arranged in rows separated by a service gap. The structures can comprise cross members that can be varied in size. By altering the size of cross members in a structure, heliostats in one row can be deployed farther apart or closer together than heliostats in a different row. Heliostat field density can vary with distance from the receiver tower, wherein heliostats close to the receiver are more tightly packed and heliostats further from the receiver are spaced farther apart. Heliostat subgroups can exhibit variable heliostat density using one or more of the following features: variable spacing of heliostats within the same row, variable spacing of heliostats mounted to the same structure, or by varying the width of the service gap between rows. The result is a field configuration that reduces the blocking and shading of heliostats by their neighbors.

1 . A heliostat array comprising:
 a plurality of heliostats mounted onto structures;   a plurality of heliostat subgroups comprising at least one heliostat structure, wherein the density of heliostats varies throughout at least one of the subgroups; and   a receiver tower facing the plurality of subgroups from at least one side.   
     
     
         2 . The heliostat array of  claim 1 , wherein each heliostat comprises a two-axis drive assembly and a reflector mounted to the drive assembly. 
     
     
         3 . The heliostat array of  claim 2 , wherein the heliostats in the array are configured to track the sun and reflect light from the reflector onto the receiver tower. 
     
     
         4 . The heliostat array of  claim 2 , wherein each heliostat structure comprises at least one structure post having an interface for attaching to the drive assembly of at least one heliostat, wherein the structure posts are fastened to the ground. 
     
     
         5 . The heliostat array of  claim 4 , wherein adjacent structure posts are interconnected by cross members. 
     
     
         6 . The heliostat array of  claim 1 , wherein the heliostats in each subgroup are arranged in rows, and wherein rows are separated by a service gap. 
     
     
         7 . The heliostat array of  claim 7 , wherein the service gap between heliostat rows in the same subgroup or in different subgroups varies depending on the distance of the rows from the receiver tower. 
     
     
         8 . The heliostat array of  claim 7 , wherein the distance between adjacent heliostats mounted to the same structure varies depending on the distance of the structure from the receiver tower. 
     
     
         9 . The heliostat array of  claim 7 , wherein the distance between adjacent heliostats in the same row varies depending on the distance of the row from the receiver tower. 
     
     
         10 . The heliostat array of  claim 7 , wherein adjacent heliostats in row or mounted to a structure are connected to each other via inter-drive cables that distribute both power and data communications.