Optimizing CPV Systems for Thermal and Spectral Tolerance

Abstract

Martifer Solar, in collaboration with the Instituto de Energía Solar of the Universidad Politécnica de Madrid (IES) in Madrid, has developed a new CPV system. The IES provided the optical design and helped to select component suppliers. The scope of the project is to provide a state-of-the-art system with minimal technical risk: i.e. a well-executed rather than novel system that leveraged the capabilities of the current CPV supplier ecosystem. Early on, a choice was made to use all-glass optics: a silicone-on-glass primary lens combined with a molded glass secondary optical element (SOE) as the choice that would combine high performance and reliability. As recent work has shown, when designing concentrator systems with SOG lens their high sensitivity to temperature must be taken into account, and it is shown how an appropriate SOE can reduce this sensitivity. In this paper, we discuss best practices for implementing concentrator systems using SOG primaries and DTIRC SOEs, and show how a range of characterization techniques may be used to optimize them, including the study of their performance sensitivity to focal distance and temperature. We discuss early performance results for the system and show how the final system shows reduced thermal and spectral sensitivity compared to other systems.