Impact of urban heat island and global warming on multi-energy complementarity optimization of buildings: application to typical office buildings in Hangzhou, China

Amid global warming and urbanization, building energy systems face the dual challenge of balancing growth in energy demand with environmental sustainability and resistance to future climate change. This study proposes a predictive framework that integrates the effects of future climate change and urban microclimate into energy consumption prediction and energy system optimization for typical office buildings in Hangzhou, China. First, optimal general circulation models (GCMs) from CMIP6 are selected through a performance evaluation, and statistical downscaling is employed to generate future typical meteorological year (TMY) data. Next, the urban weather generator (UWG) is used to simulate urban heat island (UHI) effects. Empirical formulas are applied to calculate urban wind speeds, while DesignBuilder is used to model solar radiation and hourly energy consumption. These data are then used to optimize the building energy system. The results reveal that future climate change significantly increases cooling demand (28.9%–103.0%) and reduces heating demand (19.7%–52.6%), with urban microclimates further amplifying these trends. The energy system optimization demonstrates that the net present value (NPV) of future climate and urban microclimate scenarios is 5.1%–16.7% higher than that of historical climate scenarios. Additionally, future climate scenarios result in higher peak energy demand and thus necessitate larger system capacities to ensure reliability. While the initial required investment is higher, buildings optimized to account for global warming are more reliable and carry lower operational costs. We comprehensively quantify the effect of future urban microclimate on building energy systems, emphasizing its critical role in energy system planning and providing insights for addressing the challenges of climate change and urbanization.