Thermo-optics of Luminescent Solar Concentrators

ABSTRACTWe present a numerical study on effect of temperature on the performance of a waveguide luminescent solar concentrator (LSC). The purpose is to determine how changes in temperature of the ambient environment of an LSC affect device performance. The thermo-optical coefficient of the polymer waveguide is modeled using the well known Prod’homme formulation and applied in a forward Monte Carlo ray-tracing simulation. We show that the number of collected photons decreases almost linearly as the ambient temperature increases from -50 ºC to +50ºC. This behavior is associated with several competing loss mechanisms in the waveguide. For example, increases in optical confinement due to increased refractive index at low temperature are opposed by increases in cone loss (escape loss) of photons. Other competing mechanisms that exhibit temperature dependence are explained in terms of a detailed balance treatment of the LSC as a function of temperature.