A novel experimental approach is presented to study the effect of specific height (defined as the average gap between basin and glass cover) on solar still productivity for a constant water depth. Solar still with an additional absorber was proposed and fabricated for desalination of water. Distillate yields were compared for the same basin area with different specific heights (or Cavity Aspect Ratio from 1.94 to 2.67). Average daily productivity for the period of experimentation improved from 1.341 to 4.186 L/m(2)-day. A new correlation based on the experimental data is proposed to estimate Nusselt Number which accounted for the complex interaction of cavity aspect ratio and Rayleigh Number encountered in the solar still. Daily efficiency was observed to increase from 11.25% to 39.59% with reduction in specific height Water obtained from solar still was found to have improved quality suitable for drinking. It was estimated (based on economic analysis) that cost of distilled water reduced from $0.074/L to $0.024/L. Payback period of the system was found to decrease from 972 days to 234 days. The water from the solar still had an average cost estimated as $0.04/L-m(2) along with a payback period of 350 days. (C) 2017 Elsevier B.V. All rights reserved.