A high concentration rooftop photovoltaic system

Abstract

The commercial rooftop environment poses difficult challenges for concentrating photovoltaic (CPV) systems. Rooftop CPV must not only meet low cost and high energy production targets common to ground mounted systems but also must solve safety, wind loading, and area usage requirements in ways that are compatible with the rooftop environment. To meet these requirements we have developed a low-profile carousel-mounted array of Fresnel concentrators using triple junction solar cells. In this paper we describe the key features of the opto-mechanical and thermal design for manufacturability and reliability. These features include the concentration level, the mechanical drive scheme, the configuration of the lens with secondary optical element, and passive cooling. Also described are elements of the optical component testing and assembly methods. We present exemplary results of environmental testing and measurements of electro-optical performance.

Benchmarking concentrating photovoltaic systems

“…Recently, systems emerged trying to put high concentrating photovoltaic systems on rooftops. 29,30 For these new design and tracking concepts, the question of their cost-performance is vital. To address this problem, a metric for comparing rooftop concentrating photovoltaics to silicon photovoltaic cell panels can be energy per rooftop surface area in a given period of time, e.g.…”