Design and modeling of an optical band gap matched temperature controlled indoor concentrated light transmission system for photovoltaic energy production

Abstract

This paper reports, the design, and modeling of a band gap matched, actively temperature controlled indoor photovoltaic optical system for solar spectral irradiance ranging from 350 nm to 870 nm (visible and part of near infrared) by employing Cadmium Sulfide/ Cadmium Telluride (CdS/CdTe) thin layer solar cell. In this case, an existing indoor daylighting system having 45.91% efficiency is remodeled to be a more an efficient light concentrating source with an improved light transmission efficiency of 51.65% for the proposed system. Under band gap matched conditions of the light spectrum and active temperature controlled environment, for a CdS/CdTe solar cell with 0.06%/mV as temperature coefficient, a 0.5% increase in cell efficiency and negation of ∼1.7% efficiency decay due to 12 °C temperature rise is theoretically predicted. A commercially available CdS/CdTe solar cell with 860.73 W/m2 as integrated input solar irradiance and of 0.085 m2area, an outdoor efficiency of 14.52% produces 10.62 W. The modeled system theoretically predicts ∼1.16 times more energy from the same system in addition to an extended life due to indoor conditions. Modeling and simulation of the proposed system are performed by using MATLAB V-9.2 and OptiSystem V-14.0 software showing a good agreement with theoretically predicted results.