Design of a low-profile two-axis solar tracker

• A low-profile solar tracker design is proposed for utility scale PV and CSP.
• The new design utilizes two linear actuators that distribute load.
• The new design features low installation cost and lighter parts.
• Ground cover ratio is enhanced compared to a mast type tracker.

This paper proposes a low-profile tracker comprised of two coplanar and perpendicular linear actuators coupled with a single linkage arm and pivots. Two-axis solar trackers are a necessary component to all types of concentrating solar power systems with the exception of parabolic trough systems, and have also been incorporated into grid-scale photovoltaic power facilities resulting in 30% energy production gains. Use of trackers, however, necessitates additional capital and careful placement to minimize shading by adjacent trackers, as well as sturdy foundations and heavy capacity hardware when high accuracy is required. The proposed tracker is inherently accurate and sturdy due to its large base and unique linkage geometry. A prototype was built and tracking capability was demonstrated by measuring the receiver temperature from a concave mirror. The shadow footprint of the tracker is simulated and compared to existing mast-style trackers. The simulation is run to coincide with the winter solstice, when the sun is lowest in the sky, and shadows are largest. Although the tracker utilizes translational motion, no significant change in the shadow footprint is observed.