Keywords: thermal efficiency, exergy efficiency, passive solar stills, active solar stills, solar distillation
Exergetic analysis of passive and active solar stills
This paper presents an exergetic analysis for passive and active solar distillation systems. The analysis is based on mass, energy and exergy balance equations, which has not been attempted in the past for active solar stills. In the present paper, it has been tried to compare the hourly exergy and thermal efficiency of passive and active solar stills. The values of hourly exergy and thermal efficiency of passive solar still are 0.1?0.8% and 2?17% while those for active solar still are in the range 0.1?1.1% and 3 15%, respectively. In case of active solar still, the effect of water depth and number of collectors on overall exergy and thermal efficiency have been obtained.