Sunlight concentration effect analysis of lenses on single-slope solar still

In this paper, an experimental study has been conducted to monitor the productivity of a single-slope active solar still with three lenses and one mirror. The lenses and the mirror were proposed to be attached to a basin-type single-slope active solar still because of their concentration effect for sunlight. After 24-hour performance monitoring, a higher yield was observed in the new style of solar still as compared with the conventional single-slope still. The lenses refract and aggregate the sunlight from three side walls, and one mirror set on the back of the evaporator can avoid sunlight loss. Model-3 with three lenses produced about a 21.03% yield increment, and an extra 8.77% yield was observed by adding one mirror in Model-4. The yield of the proposed solar still could reach the maximum freshwater production through Model-4 (adding three lenses and one mirror) of 0.8 kg/m².d on 1/8/2016. Compared with the traditional still, there was a 29.8% increment in yield through Model-4 at 0.15 m water depth, and the production reached its peak at about 16:00.