Energy consumption simulation and renewable energy integration analysis of nearly zero-energy buildings in hot summer and cold winter climate

Abstract Nearly zero-energy buildings have become a global trend in building energy conservation. While China has achieved success in implementing such buildings in severely cold regions, improvements are still needed in hot summer and cold winter regions. This study analyzes the climate characteristics and heat transfer properties of buildings in China’s hot summer and cold winter regions, proposing both active and passive energy-saving strategies suitable for this climate. Using a residential building in Hangzhou, Zhejiang Province as a case study, we conducted a comparative analysis between conventional and nearly zero-energy buildings using GBVEL software. Through detailed GBVEL simulation modeling, we established a comprehensive analysis of building system structures including envelope configurations, material properties, and thermal performance characteristics. The simulation results demonstrate that optimized envelope structures can reduce heat transfer coefficients by up to 47% compared to conventional buildings. Various energy-saving measures were evaluated through parametric analysis, revealing that integrated approaches combining enhanced insulation, optimized window systems, and renewable energy integration can achieve energy reductions of up to 89.5%. The renewable energy integration analysis shows that a 100 m² rooftop photovoltaic system combined with ground-source heat pumps can offset 25.8% of cooling and 44.7% of heating energy demands. The study provides practical guidance for implementing nearly zero-energy buildings in hot summer and cold winter regions through a comprehensive assessment of building layout, green areas, material optimization, and energy efficiency improvements.