Effects of Environmental Factors on Photovoltaic Module Temperature Monitoring Using BOTDR

To ensure the stable operation of photovoltaic (PV) panels, this work investigates temperature monitoring using Brillouin Optical Time Domain Reflectometry (BOTDR). Optical fibers were first installed on the back surface of the PV panels, and outdoor experiments were conducted under varying ambient temperature, solar irradiance, and wind speed to measure panel temperature. Then, a temperature field model of the PV module was then developed in ANSYS under the same conditions as the experiment. The simulation results closely matched the experimental data and the model is validated. Using this model, the effects of wind speed, solar irradiance, and ambient temperature on the temperature of optical fiber and panel were systematically investigated. The difference between the average panel temperature and the optical fiber temperature was defined as the measurement error. Results show that measurement error increases with rising ambient temperature and solar irradiance, while it first decreases and then increases as wind speed increases. At higher ambient temperatures, variations in solar irradiance have a more pronounced effect on measurement error, whereas the influence of wind speed becomes weaker. In contrast, as solar irradiance increases, the effect of wind speed on measurement error becomes more significant. When the ambient temperature ranges from 5 to 35 °C, the solar irradiance ranges from 300 to 1200 W/m², and the wind speed ranges from 0 to 6 m/s, the measurement error varies between 0.62 °C and 3.07 °C, with an average value of 1.72 °C. This work provides a reference for improving the accuracy of PV panel temperature monitoring using BOTDR.