This work focuses on identifying the applications, critical challenges and future opportunities of autonomous unmanned aerial vehicles (UAV) in solar photovoltaics (PV) inspection. This paper places emphasis on aspects that require more research attention and depth that are mostly overlooked in most published research works. It therefore presents a state-of-the-art overview on the current use of autonomous UAV systems in solar photovoltaics, highlighting its major challenges and untapped potentials requiring more research. Major challenges and opportunities are identified within recent non-conventional large rooftop systems, floating and vertical solar PV systems where autonomous inspection applications are required starting from the pre-construction stage and where the requirements vary from standard ground mount systems. This is largely because autonomous systems are found to be more impactful in demanding environments. Aside from the technical aspects related to autonomous navigation, the types of sensors required and solar PV monitoring, beyond visual line of sight (BVLOS) and safe autonomy are also examined by using on-board backup/monitoring systems to assist with navigation and emergency landing. This is essential due to the nature of the application within complex-urban environments. It is considered that the “open research” areas will deepen regional impact, efficiency, accessibility and use of autonomous UAV inspection for solar PV and inspection activities in other sectors. Thus, enabling enormous transformation for both manned and autonomous inspection landscapes. This work therefore provides technical input on the current procedures applied, identifies the challenges, and provides recommendations on aspects where significant future progress would be most advantageous.
