Exploring aluminum as a solid thermal storage medium for solar cooking application: An experimental investigation coupled with numerical modeling using OpenFOAM.

The intermittent nature of solar energy presents a significant challenge to its reliability, particularly in applications that require a consistent energy supply, such as cooking. This issue is especially critical in emerging economies with abundant solar resources, where sustainable energy solutions are needed to reduce reliance on traditional fuels. To address this challenge, this study introduces a novel solar thermal storage (STS), utilizing a metal-based material to accumulate and retain heat for off-sunshine hour cooking. The research focuses on optimizing aluminium as the STS material, evaluating its temperature suitability, efficiency, and heat retention capabilities for household solar cooking applications. Numerical simulations using the OpenFOAM framework were conducted to analyze heat transfer within the cooker, determining the optimal size of the aluminium block based on existing literature and predefined parameters. Practical experiments, including solar-induced heating-cooling cycles and controlled cooking tests, were carried out to validate the findings. Experimental results demonstrate STS's ability to efficiently absorb and retain heat, reaching a maximum of 235 °C during a 5.5-h heating session. The water boiling experiment further confirmed STS's practical utility, effectively transferring stored heat to cooking tasks and sustaining temperatures up to 160 °C even after the test. Additionally, experiments with black lentils and chicken stew highlighted aluminium's suitability for practical cooking applications, showcasing its ability to sustain high temperatures and efficiently transfer stored heat despite longer cooking times. The study's novelty lies in integrating numerical modeling with experimental analysis to optimize STS systems, providing practical guidelines for efficient thermal storage in cooking applications. This research advances beyond previous efforts by providing a validated methodology for the design and optimization of thermal storage systems. It improves the reliability and adaptability of solar energy for cooking applications.