Solar energy was utilized as a clean renewable heat source for operation of a multistage flash (MSF) distillation system in Benghazi to produce distilled water. The optimum T-h for operation of the MSF system with a typical Aat-plate collector is 80 degrees C; 1 m(2) of a flat-plate collector produces annually 8.2 m(3) of distilled water at T-h = 80 degrees C. When 1 m(2) of a compound parabolic collector (CPC) is used at T-h = 122 degrees C, 13.1 m(3) of distilled water are produced.