Experimental Comparison of Two Specialized Cooking Pots During Partly Cloudy Conditions Using Parabolic Dish Solar Cookers
Abstract
Solar cookers perform well during sunny days, but their performance during cloudy periods is poor. Most of the solar cooking tests presented in recent literature, including the test protocols, are for ideal clear sky sunny conditions with little or no clouds. Very little work has been reported on solar cookers in partly cloudy conditions. This work compares two specialised cooking pots using 1.5 m parabolic dish solar cookers to evaluate their performance during partly cloudy conditions. A 4-litre pressure-cooking pot is compared to a 4-litre heavy base cooking pot under partly cloudy conditions to see if it is possible to boil water in variable high and low solar radiation conditions caused by cloud cover. With an average partly cloudy solar radiation value of 549 W/m^2 for the heating period up to boiling, the pressure-cooking pot can boil 4 litres of water in 1.1 hrs. This is faster than the 1.3 hrs the heavy base pot takes at an average solar radiation of 570 W/m^2. The average thermal (water heating) efficiency is 33 % for pressure-cooking, greater than the heavy base pot of 26 %. Two additional experimental tests performed with 2.0 and 4.0 kg of water also show better performance for the pressure-cooking pot than the heavy base pot. The results obtained support the use of the pressure-cooking pot during partly cloudy conditions.
Keywords
Experimental, Partly cloudy conditions, Parabolic dish solar cookers, Specialised cooking pots, Thermal efficiency