Performance and testing of two models of solar cooker for animal feed

Two simple solar cookers, one made of clay and locally available materials, and the other of exfoliated vermiculite and cement tiles, have been designed, fabricated and tested. The comparative performance of both cookers is described, and their efficiencies are 22.6 (clay) and 24.9% (vermiculite), respectively. The cookers are capable of boiling 2 kg of animal feed per day, and represent the equivalent of 1350 MJ of fuel per year at Jodhpur. Payback periods for solar cookers made of vermiculite tiles vary from 0.50 to 3.47 years, depending upon the fuel they replace. The shorter payback period suggests that the use of the cooker is economical.