Modelling of solar irradiance and daylight duration for solar-powered UAV sizing

Abstract

Solar energy from the sun is the largest available renewable energy that enhances the endurance of a solar powered unmanned aerial vehicle. However, harnessing this solar power is a great challenge. This is due to having solar module system's power output efficiency of only about 15-30%. However, a solar powered unmanned aerial vehicle has the potential to outperform a battery only operated unmanned aerial vehicle, especially when task being a pseudo satellite which requires long operating hours. The atmospheric conditions and geological locations undoubtedly the main cause for poor performance of these solar modules. In spite of its prolific improvement in solar cell efficiency over the years, the overall solar module system barely converts half of sun's power into electricity. Therefore, this situation makes the current system unattractive to be widely used for energy harvesting. Recent attention has been focused not only on type of solar cells but on its positioning system. However, there were lack of understanding and research on the solar irradiance intensity and daylight duration's effect on the power output. Therefore, a comprehensive model was developed to study on how the sun movement affects the solar module system's performance. This simulation model has identified the daylight duration is more important in comparison to the available solar irradiance. Moreover, the higher the solar irradiance and daylight duration, the solar module system gives the most power output. The daylight duration also depends on the latitude where the higher the latitude gets, the longer the daylight duration. Besides, the longitudinal coordinates and elevation have minor effect on the daylight duration estimation. In other words, in summer, the northern hemisphere has more advantage compared to the southern hemisphere locations and vice versa.

Influence of the Sun Position and Platform Orientation on the Quality of Imagery Obtained from Unmanned Aerial Vehicles

“…The article shows changes in the direction of the illumination of the array depending on the difference of yaw angle and Sun azimuth. Including these parameters in the UAV image correction is necessary because (as shown by other studies), the solar irradiance angle is influenced not only by the height of the Sun, but also by its azimuth [32].…”

Perpetual Solar-Powered Flight across Regions around the World for a Year-Long Operation

“…The SI density varies widely [16,17] because every city has different climate conditions; thus, the optimal sizing of solar-powered UAVs also differs because of the number of required solar cells along the wingspan to supply the required power during the flight. No specific optimization design for solar-powered UAVs suitable for continuous flying at various SI intensity environments has been reported.…”

“…The total platform weight management, ratio of the solar module to the wing area, and solar module power are crucial factors to achieve a lightweight UAV that contributes to long flight endurance [16,17]. Hence, the power obtained from the solar module, which then charges the battery pack, must produce the required power, Prequired (see Equation (5)) to sustain a level flight.…”

Development of Design Methodology for a Small Solar-Powered Unmanned Aerial Vehicle

“…The power available through the solar module facilitates the sufficiency of the solar energy harnessed for the power required. The equation is adopted from [23][24][25][26][27], which begins by determining the input parameters, including the day of the year, latitude, longitude, and altitude of the place of interest.…”