Lighting performance investigation of heat insulation solar glass (HISG) for potential utilization in greenhouses as facade material

In this short communication, a novel thin-film photovoltaic glazing material called heat insulation solar glass (HISG), which has recently been developed at the University of Nottingham, is introduced and its lighting efficiency for the potential utilization in greenhouses as a unique facade material is theoretically and experimentally investigated. Within the scope of the research, lighting performance assessment of HISG is presented in a comparable way with the conventional facade technologies such as ordinary single or double glazed building elements. Two test houses consisting of HISG and ordinary glass are constructed, and the lighting efficiency is evaluated for each glass house for different climatic conditions. Visual quality is also investigated through several retrofitting cases. The results indicate that HISG curtain walls provide 24.9% better lighting performance than ordinary glass curtain walls in terms of average values. This result can be attributed to the superior sandwich structure of HISG containing photovoltaic module and highly reflective film, leading to notable increase in light reflection into the house and thus sensible enhancements in lighting levels.