Commercially available silicon solar cells have reached efficiencies approaching their theoretical limit. This implies that the performance of Si-based photovoltaic (PV) modules is depended on the materials utilised within the module. As the PV market is working towards sustainability and a circular economy, the performance and longevity of PV modules is vital. Outdoor Electroluminescence (EL) imaging of large-scale PV power plants has become a standard practice to identify defects and electrical problems in modules. A technique that is similar to EL imaging is photoluminescence (PL) imaging. PL imaging has its advantages compared to EL imaging, as this can be done in daytime while the PV plant is in operation, utilising the sun as the photo-excitation source. In this study, outdoor PL imaging of commercially available silicon PV module is demonstrated and the usefulness of the technique to identify performance limiting defects and abnormalities in PV modules is illustrated.