Journal of Korean Institute of Architectural Sustainable Environment and Building Systems ISSN:1976-6483(Print) 2586-0666(Online) 한국건축친환경설비학회논문집

As Zero Energy Building (ZEB) certification has become mandatory, photovoltaic (PV) systems are being more actively considered in building design. However, ECO2, the government-approved evaluation tool for ZEB certification in South Korea, does not support 3D visualization or shading analysis. To address this limitation, this study developed a SketchUp-based PV system design tool that integrates ECO2 with a GPU-accelerated ray-casting shading analysis algorithm. To examine its applicability, simulations were conducted for 30 buildings near M University in Daejeon, and PV generation results with and without shading consideration were compared. The results showed that 17 out of 30 buildings exhibited reduced PV performance when surrounding shading was considered, with a maximum annual loss rate of 6.7%. Module-level analysis also showed that, even in buildings with low average shading impact, some modules experienced substantial power loss, with a maximum of 41 kWh/yr. In addition, shading effects were more pronounced under conditions of relatively low building height, short separation distance from adjacent buildings, and winter solar conditions. These results indicate that shading should be considered in PV planning for dense urban environments. The proposed tool presents a method for combining ECO2-based performance evaluation with 3D design review in the early stage of PV system planning.