Aggregated total internal reflection optics for solar: Electrical performance and thermal validation for a 7X concentrator module

An agglomeration of factors has stifled the economic promise of CPV. Foremost among these factors are: insufficient optical efficiency, misfit with existing solar infrastructure, high costs, and inadequate reliability of the optic-receiver package. These difficulties are significantly driven by the choice of optic. The CPV industry is constrained in a paradigm of bulky reflective or refractive optics that operate best at either low concentration (2-5×) or high concentration (100× and above). Low concentration approaches are plagued by marginal economics, while high concentration approaches face additional technical risks associated with 2-axis tracking and thermal management. Using aggregated total internal reflection (ATIR) as the primary optical mechanism, a cost effective, line-focus optic can be produced at scale to provide superior optical performance in a flat profile and operate at a mid level of concentration (7-10×) to optimize the tradeoff between economic benefit and adoptability. ATIR optics have been proven to have high optical efficiency, provide adequate acceptance angles, deliver uniform light on the cell and work well with a variety of existing cell architectures. Prior to initiating a full reliability program for an ATIR module, module integration and demonstration of manageable thermal performance is essential to substantiating the design. Electrical and thermal performance data from an arrayed module and traditional module correlates serves to bolster the case for the ATIR approach.