The combined impacts of global warming and urban heat island on energy demand and balance of a zero-energy building

Zero-energy buildings (ZEBs) are essential for achieving carbon neutrality. However, global warming and the urban heat island (UHI) effect have a significant impact on building energy demand, and their combined effects have been largely overlooked in current studies. This can lead to inaccuracies in evaluating the future energy performance of ZEBs. This study investigates the combined effects of global warming and UHI on the energy demand and energy balance of a ZEB located in Virginia, USA, under future climate conditions. Vatic Weather File Generator (VWFG) and Urban Weather Generator (UWG) models are used to downscale future climates based on RCP 4.5 and RCP 8.5 scenarios. Then, the influence of combined effects on the future energy demand is assessed using Design Builder. Results indicate that total energy demand for space heating and cooling is predicted to increase by 24% under the RCP4.5, and by 38% under the RCP8.5 scenarios from 2021 to 2100, driven by global warming and the UHI effect. Additionally, photovoltaic (PV) power generation designed based on current climate conditions are expected to fall short of meeting zero-energy requirements in the future 80 years. This study highlights the critical needs to consider the UHI and global warming impacts on the building energy demand to design more accurate and reliable the energy system of ZEBs.