Assessing heat transfer characteristics of building envelope deployed BIPV and resultant building energy consumption in a tropical climate

Abstract

Building-Integrated Photovoltaic (BIPV) is a viable technology towards increasing renewable energy production and achieving low carbon footprints for buildings. Mauritius, with a daily average of 5.6 kWh/m2 of solar radiation over 2350 h annually, has been targeting at achieving its low carbon goals by focusing on photovoltaic technology including the uptake of BIPV. However, BIPV has not been well researched in terms of its overall thermal impact especially overheating on the building envelope and the resultant energy performance for buildings for the tropical climatic condition in Mauritius. This research, by means of validated simulation modelling, adopted a novel approach of coupling thermal finite element analysis (FEA) with whole building dynamic simulations to assess the heat transfer characteristics of BIPV either on facades or roof and the resultant energy consumptions of a typical office building in Mauritius. The façade scenario had two options, namely BIPV curtain wall and BIPV double-skin façade (BIPV-DSF), while the roof scenario also had two options, namely uninsulated and insulated roof BIPV membranes. Results show that roof BIPV membrane options had a better thermal performance in reducing overheating for the building compared to the BIPV façade options, with a reduction in cooling load of 8% and 15% for the uninsulated and insulated BIPV membranes, respectively. In terms of energy performance, both BIPV façade options were not capable of reducing the energy consumption of the building, as the BIPV curtain wall resulted in 1.66% more net energy consumption on a yearly basis. This shows an ineffectiveness of using vertical BIPV glazing for typical office buildings in Mauritius. Although the BIPV-DSF achieved an annual net energy saving of 5.16% benefited from the BIPV energy production, it was not as good as the net savings of 160% and 172% from the respective uninsulated and insulated roof BIPV membrane options.