## 4 Measures to Overcome the Challenges
### High Temperature of BIPV System  
The author [51] experimentally examined the developed unglazed transpired collector (UTC) prototype with black-framed PV modules of 70% area, and the remaining area has a porosity of 0.6% to allow fresh air to enter as shown in Figure 8. It can be observed that a fan was provided at the top of the facade duct for cooling the PV modules and providing pre-heated air for other purposes. A study also experimented with a DC fan on the wall upper vents, and it was reported that PV cell temperature was reduced by 1.28 \({}^{\circ}\)C, and the pre-heated air was further utilized as per the thermal comfort requirement (Figure 9) [52].  
It was found that the DC fan electrical efficiency of the PV modules was 10% to 11%. The author [53] experimentally performed cooling of the PV module through a DC fan controlled by the PIC18F4550 microcontroller, which depends on the average value of module temperature (Figure 10). It was seen that cooling can increase the electrical conversion efficiency by 7-8% compared to without cooling. The energy consumption required during forced ventilation was not reported by the researchers which needs to be considered when applied on a large-scale basis. Moreover, as the solar radiation, wind velocity, and ambient temperature are intermittent parameters, the duct width and airflow therefore have to be controlled as per the average temperature of the PV arrays and the optimum temperature requirement for the thermal comfort in the buildings.  
Figure 8: Schematic for BIPV/T system [51].  
In the above discussion, there are different methods implemented for cooling the PV panels through the fans manually. To implement IoT in automating the fan to cool the panels based on sensory data. Figure 11 illustrates an IoT-assisted architecture for cooling the fan through sensors and wireless communication protocol. The 'n' number of sensor nodes and fan controller units are the two different units that will be embedded in the building for the automation of fans to cool the solar panel temperature. The number of sensor nodes and fan controlling units can be customized depending on the building area. The sensor node embedded in the PV panels monitors the temperature and in case the temperature exceeds the normal range, the sensor node alerts the fan controller unit to  
Figure 10: (**a**) Development of DC fan cooling mechanism and temperature distribution through the front surface PV panels for different mode operation PV panel temperature, (**b**) rear side of the panel having a (**c**) DC fan [53].  
Figure 9: BIPV facade provided with vents and DC fan [52].  
turn on the cooling fan through LoRa communication. The fan controller unit controls the cooling fan through the relay.  
The sensor node connects the PV panel temperature monitor and cooling to the cloud server through the LoRa-based gateway. The LoRa connection is established among the sensor node, fan controller unit, and the LoRa-based gateway enabling long-range transmission of data along with low power consumption. As LoRa can transmit the data in the long-range, it is feasible to place a LoRa-based gateway in such a location where the internet connectivity is stable. The Wi-Fi module in the gateway enables connection to the internet and logs the information on the cloud server that is received from the sensor node. The cloud server is managed by the authorities, and they can monitor the PV panel's temperature and cooling fan on the digital platform from any location in real-time through internet connectivity.