The Experimental Investigation of a Solar Still Coupled with an Evacuated Tube Collector

Solar distillation is a promising method for clean water supply to rural communities where the quality of water is poor and sunshine is abundant. Due to a lower yield of water distilled in a passive solar still, it is not popularly used and commercialized. Various active methods were developed to overcome this problem. A newly designed solar still coupled with an evacuated tube collector (active solar still) and passive solar still for comparison purposes were fabricated and tested at Solar Energy Park, Tamilnadu College of Engineering, Coimbatore (Latitude: 11 degrees N; Longitude: 77 degrees E and an altitude of 409 m above sea level), Tamilnadu, India. Experiments were conducted under various meteorological conditions from June 2009 to March 2010. It has been found that maximum daily distilled water production of 7.03 and 3.225 kg obtained in active and passive solar stills, respectively, at a water depth of 0.04 m. It has also been observed that the efficiency of an active solar still is lower than the passive solar still in high temperature operations.