HelioSliders: Novel Heliostat Field Design Approach based on Collision Analysis of Shadow Projections

This paper presents HelioSliders, an innovative, pattern-free methodology for heliostat field design that is applicable to both single-focus and multi-focus Solar Tower systems. By projecting the heliostat mirror outlines onto a horizontal plane - using perspective projection from a designated aim point for blocking and parallel projection along the sun vector for shading - the algorithm generates two-dimensional blocking and shading contours. These representations are used in a 2D rigid-body simulation in which each heliostat is dynamically repositioned within defined inner and outer boundaries. The algorithm ensures that the overlapping of the blocking and shading contours of neighboring heliostats is minimal. An artificial gravitational force draws the heliostats toward the receiver, thereby minimizing spillage and atmospheric attenuation. The HelioSliders method is demonstrated through optical benchmarks using ray tracing, where its performance is compared with three reference designs that cover both conventional single-focus Solar Tower systems and advanced multi-focus Beam-Down configurations. Compared to the reference designs, HelioSliders achieved a relative increase in annual optical efficiency of 1.4%, 0.9% and 0.8% and a relative reduction in field area of 21.0%, 13.2% and 0.3%, for the Gemasolar, PS10 and Bi-Focal Beam-Down scenarios, respectively. Sensitivity analyses show that optimizing parameters - HelioSliders algorithm-related, but also system-related, such as the heliostat aspect ratio - can further improve annual optical efficiency and reduce the field’s physical footprint. The results highlight that HelioSliders offers a versatile, computationally efficient, and adaptable framework for designing highly efficient heliostat fields.