Simulation-based retrofit design for energy efficiency in detached social housing amid rising CO2 emissions

Amid the global increase in the residential sector’s electricity supply, demand, and consumption due to growing population and affluence, a sizeable amount of the UAE’s residential properties continue to depend on conventional electricity supply from the national grid. Nevertheless, the annual rise in residential sector electricity uses and subsequent carbon emissions can be mitigated by promoting grid-tied photovoltaic installations, especially in social housing developments, to serve as exemplars to the private sector. Therefore, this study aims to demonstrate a simulation-based method in proposing energy efficiency retrofitting measures for the Sheikh Zayed Housing scheme, which is a public housing estate in Ajman, UAE. This study utilized Sketchup and Sefaira, which are digital design and analysis software to determine building energy and daylighting performance of seven retrofitting concepts for four different villas. The concepts include baseline, baseline with photovoltaic systems covering 50%–100% roof areas, baseline with photovoltaic, window shading, and/or internal Venetian blinds. This study also estimated the performance of proposed photovoltaic systems using PVWatts and calculated the simple payback time with a sensitivity analysis. It was found that four concepts are able to either produce more than 30% excess electricity for future electricity consumption expansion (Y6 and Z6) or offset up to 78% of simulated annual electricity demand (ZT7 and ZS7). The sensitivity analysis highlighted that high tariffs and strong PV yields guarantee rapid payback (<1 year). Overall, the methodology used in this study can be replicated onto other housing schemes, while the findings can be used as a benchmark for future energy efficiency retrofits in the UAE.