Efficient light collection in solar concentrating systems

Thesis (Ph. D.)--University of Rochester. Institute of Optics, 2018Light collection plays an important role in solar energy applications. The more efficiently solar irradiance can be transferred to photovoltaic (PV) or thermal receivers, the higher the total system efficiency can be. The scope of this research is twofold: 1. novel optical designs of spectral splitters for concentrated photovoltaic (CPV) applications and 2. concentrator and receiver modeling and design for concentrated solar power (CSP) systems. This research uses novel optical design forms to collect and deliver light to more than one photovoltaic detector for efficient conversion of solar light into electrical current. A back surface reflector (BSR) on a primary high efficiency solar cell allows light to be absorbed and then redirected to a secondary high efficiency cell. This type of spectral splitting has the added value over the typical dichroic that is used in a multi-cell module because a BSR is polarization independent and is effective over a wider range of incident angles. Innovative geometries for concentration and alignment are presented. Efficient light collection in CSP and thermal applications such as large-scale thermal power towers is important to effectively heat the receivers or heat transfer fluid. This research models two existing solar simulators and designs novel solar thermal receivers for use in these two simulator settings. The chosen thermal receiver is built and tested in laboratory experiments to study the heat transfer under a range of heat transfer fluid flow rates