The paper examines the experimental performance of air–rock bed, oil only, and oil–rock bed systems for storing heat suitable for cooking applications. The air–rock bed system is charged using hot air from a compressed air tank, while the oil–rock bed system employs a resistive heating element to heat a small volume of oil, which then circulates naturally. The charging process for the oil systems was controlled by adjusting funnel heights, and temperature measurements were taken using thermocouples connected to a data logger. Both systems can store thermal energy ranging from 4.5 kWh to 8 kWh and achieve temperatures between 150 °C and 300 °C, depending on supply temperatures. The simpler oil–rock bed allows for the direct boiling of water using the high temperature produced, and tests indicated comparable boiling times between systems. The findings suggest that these heat storage systems could enhance the advancement and integration of solar cookers, enabling more flexible cooking options.

The study introduces a solar-powered electric cooking system designed for households in sub-Saharan Africa. It uses a 330W photovoltaic (PV) panel directly connected without a battery, to ten parallel Positive Temperature Coefficient (PTC) heating elements mounted on a 20 cm diameter circular aluminium plate to form a “PTC hot plate.” An Arduino controller manages the load and records system data (current, voltage, power, and temperature). Cooking tests under different weather conditions showed practical performance: 0.5 kg of beans cooked in ~3 h using 1.4 kWh; 1.0 kg of beef in 1.5 h using 1.1 kWh; and 0.5 kg of rice in 1 h using 0.73 kWh. Boiling 2 liters of water took about 25 min. Sequential cooking (rice then beans), starting at 9:45 h was completed by 14:30 h. The average cooking efficiency was evaluated to be about 54%, dependent on the duration of cooking and the food type being cooked. A minimum solar irradiance of about 400 W/m2 per day was required for effective cooking. These results demonstrate that the solar PV-PTC cook stove is a viable and promising solution for meeting household cooking needs in the sub-Saharan African region.