Effect of Cover Plate Transmittance on Solar Still Performance

The year round performance of solar still mainly depends not only on the variations of solar radiation incidence on the glass covers and also on the solar energy transmittance variations of the covers. In this work, a single basin double slope solar still has been theoretically modeled. The year round variations in radiation energy incidence, transmitted and lost at the covers and the total production of the still for the local place, Kovilpatti (9 degrees 11'N, 77 degrees 52'E), India, have been studied using the model. During January, February, November, and December, the north cover experienced around 25% of energy loss. But, the loss at south cover is only 15-20% during different months of the year. The still production is minimum (2.7 L/m(2)/day) during June and maximum (6.5 L/m(2)/day) during March. The yearly average production of the still is 4.75 L/m(2)/day. The payback period of the still is one and half years. The actual production of the fabricated still was close with the estimated values.