Abstract

The long-term aim of this study is to develop low cost technology for the poor rural dwellers of Nigeria along the coastal areas. To this end, a comparative evaluation of two basin type passive solar stills was undertaken by distillation of salty water. The solar stills were rectangular-shaped and pyramid-shaped type. Both stills were made of the same material and of the same size. The top of the rectangular-shaped type is sloped and inclined 22^o to the horizontal in the north-south direction. The temperature analysis of the systems show that during the day the rectangular-shaped still performed better giving a higher basin and subsequent higher saline water temperature with lower glazing temperature when compared to the pyramid-shaped with lower basin and saline water temperature but with higher glazing temperature. The rectangular-shaped solar still gave an average efficiency of 36.8% while the pyramid-shaped type performed at 28.9% efficiency. Hence the rectangular-shaped solar still in comparison with the pyramid-shaped type is recommended for use to especially people living in coastal areas.

Key words: Solar still, distillation, saline-water, rectangular, pyramid.