Modelling the effect of BIPV window in the built environment: Uncertainty and sensitivity

Abstract

BIPV (building-integrated photovoltaic) window has been proven as a promising technology to increase renewable energy and reduce environmental effects of the building. The effect of BIPV window in the built environment could change significantly with the window configuration, building materials, and urban landscape, which have a large variability within cities. In this study, we adopted a newly developed building energy model coupled with a single-layer urban canopy model (BEM-SLUCM) to characterize the uncertainties of BIPV window effect at the neighbourhood scale in a hot desert climate city, Phoenix, USA. Using an advanced Markov chain Monte Carlo algorithm, extensive simulations were conducted to quantify the sensitivity of extreme outdoor microclimate, building cooling load and renewable energy generation to various input parameters. Results show that the canyon aspect ratio, window coverage, and power generation efficiency are pivotal to maximize the electricity generation by BIPV window. Canyon air temperature and building cooling load are highly sensitive to momentum roughness length above canyon, thickness of building envelope, air conditioning setpoint temperature, and canyon aspect ratio. This indicates a strong dynamic interaction between building's indoor space and the surrounding canyon environment. In contrast, thermal and optical properties of BIPV window have negligible effects on the urban thermal environment. Findings in this study reveal key mechanisms that regulate the urban microclimate and building energy consumption, provide guidance for BIPV applications in the built environment, and shed new lights on the sustainable design of urban neighbourhoods.