Some modules with back-sheet scratches were detected. Cables loosely hanging from the modules were found. Module-to-module earthing is absent. It is recommended to (i) add earthing connections between modules, (ii) replace the cleaning equipment used, (iii) replace modules with back-sheet damage and melted connectors, (iv) replace rusted components of the mounting structure, and (v) install a weather station or at least an irradiation sensor on the module plane to quantify and monitor the performance ratio. The estimated production boost expected by the retrofitting actions lies between 7% and 9%.