## 4 Measures to Overcome the Challenges
### Dust Accumulation on BIPV  
The accumulation of dust on PV modules can deteriorate the energy output of the PV modules by around 20% to 40% [58]. It has become essential to rectify the problem of dust accumulation and significant losses in the PV system. The percentage or rate of dust accumulation may vary as per the wind pattern and ambient condition of the surroundings. Practically, the accumulation rate was higher in areas with dry winds and high vehicular movement, dust storms, etc. After the accumulation of dust, a layer was formed over the surface of the PV modules This affects the performance of the PV modules. Figure 17 shows  
Figure 16: Proposed architecture for fault detection using edge computing with AI/ML. the scenarios of the BAPV system on the rooftop with and without scheduled cleaning. In Figure 18 the variation in PV module efficiency due to the dust accumulation on modules was shown, it can be observed that the reduction in efficiency varied from 10% to 80%. In general, manual cleaning of PV panels whether installed on building roof or facade was performed within a certain time interval The cleaning can be performed manually using the long stick brushers or through the washing technology (Figure 19). However, manual cleaning of a panel on buildings is a high concern for safety. In automated cleaning, fully or partially automatic robots were used. The robotic cleaning can be water-based or water-free. Robotic cleaning demands low consumption of fuel, and no labor cost and with no intervention of a human, it also resolves the safety concerns of manual cleaning. It was reported that with fully automated cleaning the soiling rates can be reduced by 95% [58]. The researcher experimentally studied the potential of cleaning solar panels using a low-cost automated robotic cleaning system (Figure 20) [47]. The system consists of a silicon rubber brush foam mounted on an aluminum core. It  
Figure 17: The Solar PV plant was installed at the Science and Technology Park, in Doha (State of Qatar) (**a**) scheduled cleaning and (**b**) dust particles accumulated on PV modules [59]. Figure 18: The monthly reduction in PV module efficiency due to the dust accumulation [58]. was observed that the robotic arm was capable of minimizing the solar panels' dust and providing an increase in power output compared to weekly-cleaned PV modules. The author [46] used an image processing technique for predicting the accumulation of dust on PV modules. The high-resolution images were captured from the aerial robots. The dust detection algorithm was developed, and performance was assessed in the MATLAB image processing toolbox. Further, the algorithm is validated against electrical measurement where it showed a variation of 5% to 5.5% of detection variation in the developed algorithm. The author [45] develop a central monitoring system for detecting the dust accumulation over the PV panels using drones as shown in Figure 21. A radiometric sensor was connected with the Arduino platform. The sensor detects the emissivity level of the PV modules, which determines the presence of dust over the modules, further the results were validated through IR images taken during the analysis. The results were sent and analyzed through IoT. However, different angles and height of the UAV have to be monitored for analysing the accuracy. Further controlling the data acquisition from the sensor (ON/OFF) with the help of a Wi-Fi-enabled switch according to the requirement can save around 58% of energy as well as the life of sensors [61]. Figure 19: Manual cleaning of PV modules on the building rooftop [60]. Figure 20: The robotic cleaning system was installed in the test field [47]. It was found that most of the module cleaning studies were performed on the horizontal and tilted PV panels installed either on the building rooftop or on the open ground. For high-rise buildings, the cleaning of panels can be implemented as discussed by [62], and the cleaning robots can be installed on the top or bottom of the envelope edge.