The feasibility of a roof-type multistage solar still for agricultural use was studied by estimating the protection effect of plants from strong radiation and the capability of self-supply of required water. The results showed that when using a 5-stage solar still as a simple shelter for plants in hot arid climates of the Middle East, it produces distillate 8 fold the crop consumption at initial crop stages, 2 fold at crop midseason, and 3.8 field before crop harvest. When using it as a roof for greenhouses, the distillate productivity reaches 17-fold evapotranspiration inside the greenhouse. © 1989.