Experiment and simulation to determine the optimum orientation of building-integrated photovoltaic on tropical building façades considering annual daylight performance and energy yield

Building-Integrated Photovoltaic(BIPV)on vertical façades is a potential PV application in today’s buildings.The performance of BIPV on façades is significantly influenced by the façade orientation.For tropical cities,the optimum façade orientation,in terms of maximum energy yield and daylight performance,cannot be simply determined,due to relatively symmetrical sun path throughout the day.This study therefore aims to determine the optimum orientation for BIPV on tropical building façades.To achieve the objective,experiment,modelling,and computational simulation are conducted to evaluate the BIPV energy yield and to predict the indoor daylight performance in a scale-model building with a 105Wp monocrystalline silicon PV,facing each cardinal orienta-tion in Bandung,Indonesia.The South orientation yields practically zero ASE_(1000,250),providing the best annual daylight performance,and yielding the most desirable value in four out of five daylight metrics.The greatest annual energy yield is at the North orientation,providing 179-186 kWh(95%prediction interval)per year,but with larger uncertainty compared to that at the South,due to direct sunlight occurrence.Based on three different objective functions,the South orientation is considered optimum for placing the BIPV panel on the prototype façade in the location.

Layout graph model for semantic façade reconstruction using laser point clouds

Building façades can feature different patterns depending on the architectural style,function-ality,and size of the buildings;therefore,reconstructing these façades can be complicated.In particular,when semantic façades are reconstructed from point cloud data,uneven point density and noise make it difficult to accurately determine the façade structure.When inves-tigating façade layouts,Gestalt principles can be applied to cluster visually similar floors and façade elements,allowing for a more intuitive interpretation of façade structures.We propose a novel model for describing façade structures,namely the layout graph model,which involves a compound graph with two structure levels.In the proposed model,similar façade elements such as windows are first grouped into clusters.A down-layout graph is then formed using this cluster as a node and by combining intra-and inter-cluster spacings as the edges.Second,a top-layout graph is formed by clustering similar floors.By extracting relevant parameters from this model,we transform semantic façade reconstruction to an optimization strategy using simulated annealing coupled with Gibbs sampling.Multiple façade point cloud data with different features were selected from three datasets to verify the effectiveness of this method.The experimental results show that the proposed method achieves an average accuracy of 86.35%.Owing to its flexibility,the proposed layout graph model can deal with different types of façades and qualities of point cloud data,enabling a more robust and accurate reconstruc-tion of façade models.