Abstract

Numerous types of heat storage materials have been tested to achieve a higher solar cooking rate globally under different designs of solar cookers. Here, efforts have been made to provide a low-cost solution to box cookers using two different high-capacity sensible heat storage materials (SHS), such as pebble stones and a newly developed energy storage material prepared by mixing black cement with carbon black powder in an optimum ratio of about 15:85. Results have been compared with a similar cooker to observe the variations. Cooking trials have been conducted during sunny days in March to obtain the required thermal performance parameters. Results of the cooking trials for the optimally configured (newly developed SHS) showed that F1 is about 0.12, thermal efficiency is about 59.1%, and the overall heat transfer coefficient is about 45.1 W m?2 K?1 including the heat loss coefficient of about 4.75 W m?2 K?1. Both modified cookers (SBC-B and SBC-C) took less time to boil water compared to the reference cooker. The cost of the best-configured cooker is approximately $44.59 with a payback period of about 3.51 years. The tested cooker is suitable for cooking under low ambient conditions and during off-sunshine hours, and can be adopted by financially deprived people from rural or urban areas. © Akadémiai Kiadó Zrt 2025.