Building integrated concentrating photovoltaic window coupling luminescent solar concentrator and thermotropic material

Abstract

Building integrated concentrating photovoltaic window (BICPVW) has been proven to be used in sustainable building transparent envelopes. Unfortunately, the balance between optical and electrical properties is difficult. This paper proposes a building integrated concentrating photovoltaic window coupling luminescent solar concentrator and thermotropic material (LT-BICPVW). The luminescent solar concentrator and thermotropic layer were fabricated by bulk polymerization and glass sandwich structure, respectively. Optical models are built based on the optical properties of optical waveguide and thermotropic layer, and optical simulations are performed with Monte Carlo ray tracing technology. Window prototypes are characterized under controlled indoor experimental conditions. The experiment found that as the temperature of the thermotropic film increased from 30 °C to 42 °C, the solar transmittance of LT-BICPVW decreased by 43.3%, and the maximum output power increased by 25%. Compared with, building integrated concentrating photovoltaic window coupled with thermotropic material (T-BICPVW), the power conversion efficiency was improved by 59% at the termination temperature. The LT-BICPVW system can effectively reduce solar heat gain and avoid glare hazards, while using renewable energy to significantly increase power output. A series of predictions are made using validated optical model and tracking technique to better guide the design of PV windows in actual buildings.