Combining ray-tracing and a linear thermal model to predict the performance of a panel solar cooker under varying solar angles

Panel-type solar cookers are low-cost, lightweight systems that are easy to assemble using readily available materials, making them well suited for sustainable energy initiatives in low-income or displaced communities. These cookers usually rely on manual azimuthal sun-tracking, but their optical performance is sensitive to the solar elevation angle, which can vary significantly during a typical cooking session. Such variability directly affects the overall thermal performance of the cooker, reducing the probability of successful cooking. This work introduces a combined optical and thermal simulation workflow capable of predicting the performance of a panel-type solar cooker under varying solar angles. The method is applied to the Copenhagen solar cooker, whose complex, non-analytical panel geometry is reproduced using a structural simulation of the folding process. These geometrical models form the basis for ray-tracing simulations that generate two-dimensional optical performance maps coupled to a simplified thermal model to predict heat gain under different solar angles. Simulated and experimental results agree well, demonstrating that the proposed workflow is a practical and transferable tool for performance prediction and design optimization of simple solar cooking technologies.