Session: 08-01 Thermal Energy Conversion Techniques

Paper Number: 114754

114754 - Minute-Level Solar Irradiance Estimation via the Sun-Blocking Index Derived From Sky Images 

Solar radiation also plays a critical role in determining thermal load and thermal comfort in vehicles. The irregular and unpredictable nature of cloud formation and extinction often leads to fluctuations in solar irradiance, making it challenging to maintain a comfortable climate inside the cabin without overreliance on air-conditioning systems. Cloud parameters, such as cloud amount, cloud fraction, and cloud cover, offer a limited understanding of cloud formation and do not account for the amount of cloud cover surrounding the sun disk locally. To address this limitation, this study proposes a new parameter, the sun-blocking index (SBI), to model the partial blocking of the sun by clouds. The SBI is calculated using sky images and captures the spatial and temporal variability of cloud cover in the vicinity of the sun disk, providing a more accurate representation of cloud formation. The relationship between the SBI and the clearness index is established to improve the estimation of solar irradiance. By incorporating the SBI into the clearness index, this study shows that the accuracy of solar irradiance estimates can be significantly improved. The results of the study demonstrate that the SBI model outperforms the conventional cloud cover model, achieving a relative root-mean-square error of 16.21% in estimating global horizontal irradiance.

Presenting Author: Rial Arifin Rajagukguk Kookmin University

Presenting Author Biography: Rial Arifin Rajagukguk was born and raised in Indonesia, where he developed a keen interest in the field of renewable energy. In 2017, he graduated from Institut Teknologi Bandung with a Bachelor's degree in Aerospace Engineering. With a strong passion for advancing his knowledge and skillset in the field, Rial pursued a Master's degree at Kookmin University in the Republic of Korea, where he deepened his understanding of solar irradiance forecasting. He graduated from the program in 2020 with high honors. Building upon his previous academic achievements, Rial is currently pursuing a Ph.D. at Kookmin University, where he continues to explore his interest in solar irradiance forecasting using sky camera, satellite image, and AI.