Multi-criterion optimization of integrated photovoltaic facade with inter-building effects in diverse neighborhood densities

Inter-building effects have been proved to have significant impacts on the energy and indoor environmental performance of adjacent building developments in densified urban environment. Therefore, this study presents a multi-criterion design optimization and decision-making approach for an integrated PV facade design considering miscellaneous inter-building factors as well as corresponding criteria specification in major green building assessment schemes. The impact of the surface reflectance and façade geometry is quantified for the lighting energy demand, HVAC energy demand, photovoltaic (PV) energy supply and indoor visual discomfort time respectively with a robust global sensitivity approach in diverse urban density scenarios. Wall reflection is determined to be the most important urban design factor contributing to 34%–66% variation of different performance indicators as per the availability of solar radiation on different building surfaces. Multi-dimension parametric analyses and design optimizations of PV envelope design parameters are then conducted for different neighborhood densities with fixed surface properties of peripheral building facades. Sensitivity indices of window and shading design parameters are subject to significant variation when considering surface properties of peripheral buildings. Furthermore, the performance of two different decision-making strategies (i.e. Technique for Order of Preference by Similarity to Ideal Solution and Minimum Distance to the Utopia Point methods) is compared based on criteria weightings from green building assessment schemes. The final optimum solution closest to the ideal is then determined by two-dimensional charts of objective functions. The integrated design optimization considering peripheral reflection can change the estimated net energy demand by up to 8.84% (mainly in PV supply and lighting demand). These research findings can promote the integration of synergetic energy and indoor environment design strategies and expand the penetration of renewable applications in urban areas.