The Effect of Urban Morphology on Solar Potential: A Detailed Assessment of the City of Milan in Italy

Solar energy plays a fundamental role in achieving decarbonization in the construction sector, and therefore, a detailed assessment of solar potential at the urban scale is a key tool in supporting this process. Within this framework, the present study focuses on the high-resolution evaluation of photovoltaic (PV) potential in urban environments, specifically targeting the city of Milan, Italy, where two representative study areas are selected. In detail, 3D city models are developed using Rhino3D 7 software, and a solar radiation analysis was performed using Ladybug components. The solar radiation received by the surfaces that comprise the roofs and facades of buildings is estimated for each floor and orientation, taking into account local climate conditions and shadows cast by surrounding buildings. To define the economic viability of PV system deployment, two threshold criteria were introduced: one concerning the size (area) of the PV system and the other the minimum annual solar radiation level that each surface receives. Based on the obtained data, it is found that approximately 28% of roof surfaces and 5% of facades meet these cost-effective thresholds for PV integration. Further analysis indicates that the balcony self-shading can be considered negligible in the high-density urban context analyzed. The results are beneficial for urban energy management, considering energy savings and investment approaches, and the possibility to transform existing buildings into zero-carbon buildings powered by renewables.