A review of vacuum tube based solar cookers with the experimental determination of energy and exergy efficiencies of a single vacuum tube based prototype

Solar cookers may be generally classified into direct and indirect types. The direct types include the box type and parabolic type, while the indirect types include the vacuum tube based cookers. This paper reviews the gradual progress made in the second type. The energy and exergy analysis of a single vacuum tube based prototype has been carried out experimentally. Performance parameters indicate a high peak exergy power of 55.6 W, while the temperature difference gap at half power is 38.75 K and the quality factor is 0.042. The energy efficiency of the cooker is 20-30%, while the exergy efficiency is 4-6%. These results make this compact single family solar cooker comparable in performance to large community based Scheffer type solar cookers. Results have been compared to a number of other solar cooker types.