Designing a controlled-temperature cooking pot for power-limited photovoltaic applications

The transition to clean electric cooking offers the most sustainable and environmentally friendly pathway for rural Sub-Saharan Africa, where most households still rely on traditional cooking methods and polluting fuels. However, recent electrification in these regions has primarily come from power-constrained solar photovoltaic systems, which cannot support conventional e-cookers. This creates an urgent need for specialised e-cookers operable under such limitations. This study investigates the operating conditions of such e-cookers, the optimal placement of a single external temperature sensor on them, and the implementation of temperature control functionality. Experiments using the water boiling test on a typical household aluminium pot (24 cm diameter, 10 cm height) equipped with six external and three internal thermocouples were used to examine the effects of lid use, insulation, water volume, and power input. Additional tests determined sensor placement under varying water levels and insulation thicknesses, followed by validation of temperature control using a proportional–integral controller. Results show that simple interventions such as using a lid and insulation significantly improve heating efficiency under power-limited conditions. Lower power levels (150–200 W) consumed similar energy to 250 W but required slightly longer heating times to reach steady sub-boiling temperatures, making them more compatible with slow cooking systems. A 4 cm height was identified as the optimal external thermocouple position, enabling precise temperature control within ±1 °C of the set point. These findings highlight key design strategies including consistent lid use, pot insulation, and external sensing for developing low-cost, energy-efficient smart e-cookers suited to power-limited photovoltaic systems.