Photovoltaic (PV) systems have gained global acceptance in terms of green, replenishable energy resources to meet energy demand with no emissions. However, PV systems are susceptible to operational and environmental stresses. Moreover, due to their no supervisory control, PV panels monitoring is necessary to keep its performance and efficiency intact. Therefore, this study monitors PV panels based on health into three sub-classes: healthy, hotspot, and faulty through infrared thermography. Thermographs key points are selected using an 8x8 uniform pixel grid and speed-up robust features (SURF) are extracted from grid intersection points. Afterwards, k-mean clustering algorithm due to its simplicity, creating single level clusters based on actual observations similarities and similar observations closeness within cluster and dissimilarity to other clusters observations, is used to transform features into visual words. Finally, shallow classifiers because of low training time and high prediction speed are utilized. After extensive testing and compressive analysis, the proposed approach was found economical, fast, and showed high testing accuracy of 97% through a multi-class shallow classifier (support vector machine) with low computational complexity and less storage size. Thus, this approach can be employed to monitor mega-watt PV systems with high accuracy and to keep performance and emissions mitigation potential high while lowering payback time.