Volume 9: Sustainable Energy Solutions for Changing the World: Part I

Storage and heat utilisation efficiencies of two solar storage cooking pots using different cooking loads Ashmore Mawire, Katlego Lentswe, Prince Owusu, Adedamola Shobo, Jo Darkwa, John Calautit, Mark Worall

Abstract

Two storage cooking solar pots are compared experimentally during solar and storage cooking periods. For off-sunshine storage cooking periods, the pots are placed inside insulated wonderbag slow cookers. The first storage pot contains sunflower oil as the storage material, while the second pot contains erythritol as the storage material. Storage and heat utilisation efficiencies are evaluated using five different water heating loads (0.5, 1.0, 1.5, 2.0 and 2.5 kg). The sunflower oil pot shows slightly higher storage efficiencies (3.2-4.4 %) compared to the erythritol pot (2.5-3.9 %). The storage efficiencies reduce marginally for both pots with an increase in the load. Heat utilisation efficiencies increase significantly with the load for both storage cooking pots. The erythritol storage pot shows higher heat utilisation efficiencies for most of the investigated loads (1.3-49 %) compared to the sunflower oil pot (17-46 %). The change in the cooking load has a more significant effect on the heat utilisation efficiency compared to the storage efficiency.

Keywords Erythritol; Heat utilisation efficiency; Storage cooking pots; Storage efficiency; Sunflower oil