PRODUCING DISTILLED WATER WITH SOLAR STILLS

ABSTRACT Solar stills of various types have been used for producing distilled water in the Caribbean for the past eighteen years. This paper deals with aluminium cascade solar stills operated with or without preheated feed water from flat plate solar collectors and with concrete cascade solar stills which are longer lasting and cheaper to construct and maintain. Thermal and economic performance characteristics are evaluated and their relative importance assessed under typical Third World conditions. Preheating the feed water in a G3 solar still resulted in an increase in distillate production of approximate 27%. Further increases in the yield are expected with refinement of the system.