Motorless Microtracking for Rooftop CPV

Abstract

Planar microtracking concentrating photovoltaic systems allow higher power generation in area-constrained applications. Maintaining the form factor of traditional solar panels requires a high-accuracy integrated lateral-microtracking system. We constructed a shape memory alloy-based actuator which can translate the microcells between a catadioptric pair of lenslet arrays using a few of the cells offset for feedback. This motorless approach provides a simple mechanical microtracking system with $10~\mu \mathrm {m}$ precision over a 14mm throw powered by $ < 1$ % of the panel-generated power.