Harnessing rooftop photovoltaic potential: Adoption disparities across building types in Tarragona Province, Spain

In recent decades, climate change and the global energy transition have prioritised renewable energy adoption. Rooftop photovoltaic (PV) systems have emerged as a promising solution, aligning with sustainability, decentralisation, and local energy production while efficiently using built spaces. Despite their potential, rooftop PV systems are still unevenly adopted due to technical and economic barriers. A lack of consistent data limits the ability to track adoption and support energy transition planning. This study focuses on Tarragona province (Spain) and assesses the solar PV potential of public and private buildings, including town halls, schools, libraries, and residential properties. Using GIS-based modelling and high-resolution geospatial data, including LiDAR-derived elevation models and cadastral records, we estimate that 38.72% of rooftops in the province meet suitable technical conditions for PV installation under a conservative scenario. A key contribution is the creation of a geolocated database of 18,577 rooftop PV installations through detailed photointerpretation, enabling spatial assessment of where systems have been deployed and how adoption varies by building type. Statistical analysis reveals contrasts in adoption, with residential buildings showing higher uptake, while public buildings adopted PV later. Results confirm that adoption is shaped by technical potential and sector-specific policy barriers. Findings suggest public buildings could foster broader PV uptake, leveraging peer effects and targeted incentives. This study highlights the need for accurate, publicly accessible PV installation databases to support energy planning, especially in urban and mixed-use areas. By clarifying PV adoption dynamics, this research supports informed policymaking for a more equitable, effective energy transition.