Two-Stage Lifecycle Energy Optimization of Mid-Rise Residential Buildings with Building-Integrated Photovoltaic and Alternative Composite Façade Materials

Abstract

Reducing the lifecycle energy use of buildings with renewable energy applications has become critical given the urgent need to decarbonize the building sector. Multi-objective optimizations have been widely applied to reduce the operational energy use of buildings, but limited studies concern the embodied or whole lifecycle energy use. Consequently, there are issues such as sub-optimal design solutions and unclear correlation between embodied and operational energy in the current building energy assessment. To address these gaps, this study integrates a multi-objective optimization method with building energy simulation and lifecycle assessment (LCA) to explore the optimal configuration of different building envelopes from a lifecycle perspective. Major contributions of the study include the integrated optimization which reflects the dynamics of the whole lifecycle energy use. Insights from the study reveal the optimal configuration of PV and composite building façades for different regions in sub-Saharan Africa. The lifecycle energy use for the optimized building design resulted in 24.59, 33.33, and 36.93% energy savings in Ghana, Burkina Faso, and Nigeria, respectively. Additionally, PV power generation can efficiently cover over 90% of the total building energy demand. This study provides valuable insights for building designers in sub-Saharan Africa and similar areas that minimize lifecycle energy demand.