In this work, an attempt was made for improving the performance of single basin solar still using Omani rock stone bed as an energy storage medium. The Omani rock stone bed would absorb solar energy during day time and would release the energy for vapourizing the seawater during night time. Two sets of experiments (one without rock stone bed and another with Omani rock stone bed) were conducted in this study. The productivity and thermal efficiency of the still in both cases were analyzed. It

more »

... s observed that the use of Omani rock stone bed was able to produce 2.5 litres of daily yield and able to obtain 25% thermal efficiency, which are about 19% greater than the performance of the solar still with the absence of stone bed. The quality of fresh water was verified through water quality test and confirmed its suitability for the domestic use. Keywords: single basin solar still, Omani rock stone bed, thermal efficiency, yield, water quality. INTRODUCTION The shortage of rainfall and the increase of population create water scarcity in many countries. In addition, the economic development and global warming also make a worldwide imbalance between supply and demand of fresh water. To meet out the demand of fresh water, most of seashore countries utilize various desalination techniques such as multi-effect evaporation, multi-stage flash distillation, thin film distillation, reverse osmosis and electro dialysis. The desalination techniques are energy intensive and costly towards operation and maintenance. Most of the existing desalination plants use fossil fuels as sources of energy. The use of conventional energy sources (hydrocarbon fuels) to drive these techniques has a negative impact on the environment [1-3]. Solar distillation is a most attractive, environment friendly and simple technique compared to other desalination techniques. It is well suited at the locations where solar energy is abundant. When saline or brackish or contaminated water is kept in a closed container under the open sky, it gets evaporated. The solar energy is used to accelerate the process of evaporation in the solar still [4-5]. The function of a solar still is to capture the evaporated water vapour by condensing it on a cool surface. Solar stills are classified broadly into two categories namely passive and active solar stills. Passive solar stills require solar energy for evaporation of saline water whereas active solar stills require an additional thermal energy by external mode for faster evaporation [6-8]. The passive solar still is the most economical solar still to provide drinking water for domestic applications at decentralized level. This is due to the fact that it is simple in design and fabrication, easy to handle, long life and low production cost [9-12]. Passive solar stills are available in the different configurations like basin type solar still, wick type solar still, tubular solar still, spherical solar still, parabolic solar still; fibre reinforced plastic solar still, vertical solar still, cascade solar still, staircase solar still,