System-Scale Modeling of a Building-Integrated, Transparent Concentrating Photovoltaic and Thermal Collector

Abstract

The buildings sector is a principal contributor to global greenhouse gas emissions, but consistently falls short of targets for harnessing on-site energy resources towards sustainable operation. Emerging integrated solar technologies could transform buildings and urban settings into resilient, self-sufficient, and healthy environments. But if effects of these technologies are not understood in the multiple contexts in which they operate (human-scale, building-scale, district-scale), their potential is difficult to project. To explore building-scale metabolization of solar energy, a previously-developed analytical model of a Building Envelope-Integrated, Transparent, Concentrating Photovoltaic and Thermal collector (BITCoPT) was run to project electrical and thermal energy and exergy production (cogeneration) in a range of orientations and operating temperatures. Simulated annual cogeneration efficiency was noted at 27% (exergy) at an operating temperature of 55°C, and up to 55% (energy) at 25°C. Exergetic efficiency remained nearly constant as operating temperatures increased through 75°C, indicating the thermal energy collected would be some heat-engine-based applications. Although the scope of this study excludes broader architectural benefits of daylighting (lighting load reduction), and reduction of solar gains (cooling loads), these results suggest BITCoPT merits further investigation for on-site net-zero and energy-positive commercial building design, and might contribute to expanding net-zero and energy-positive architecture opportunities.