Application of solar PV in commercial buildings: Utilizability of rooftops

Solar PV is one of the most successful renewable energy technologies being used in buildings. Buildings however pose different types of hurdles towards their utilisability for PV. Given the low power density of solar PV, buildings’ restrictive features can have a significant impact on the application of renewable technology. This study aims to investigate the utilisability of commercial buildings’ roofs for solar PV focusing on four types of buildings - shopping malls, office buildings, hotels, and hospitals. The study investigates the wide-ranging features of rooftops of these buildings which can restrict the application of PV. A total of 117 buildings have been examined in the study with the help of remote sensing techniques. Site visits are carried out for an in-depth assessment of the roof characteristics and to validate the results of the roof area estimation made through the satellite images. 16 different types of physical hurdles have been identified and classified under four main categories: architectural/structural, services, miscellaneous and associate restrictions. Roof utilization factors for the studied buildings, calculated for five different orientations, have been found to range between 0.45 and 0.52. The PV utilizable area at the city level has also been calculated with the help of a regression analysis.