Development of a rooftop solar photovoltaic rating system considering the technical and economic suitability criteria at the building level

The successful deployment of distributed solar generation in urban areas involves the evaluation of how suitable a building is for installing the rooftop solar photovoltaic (PV) system within a region. When evaluating the rooftop solar PV suitability of a building, it is crucial to consider not only its technical but also its economic performance as the difference in technical performance can lead to different financial returns for rooftop solar PV adopters. Towards this end, this study aimed to propose a method for developing a rooftop solar PV rating system using cluster analysis based on the technical and economic suitability criteria. As a result, a rooftop solar PV rating system was developed for 21,681 buildings in the Gangnam district in Seoul, South Korea by dividing them into four grades according to their rooftop solar PV potential, return on investment, and payback period. The effectiveness of the proposed rating system was validated by comparing it with the rating systems developed using the classification method and suitability criteria from the previous studies. This study has significant contributions in that it can provide the rooftop solar PV suitability information on a grade scale for intuitive decision-making based on scientific evidence and reasonable criteria.