Cleaner production of freshwater using multi-effect tubular solar still

Tubular solar still is a promising technique for freshwater cleaner production. However, the main reason lowering its productivity is the heat lost from the tube surface to the surrounding atmosphere during the condensation process. The present study introduces a techno-economical feasibility study and evaluation of using multi-effect tubular solar still to introduce a clear vision for stakeholders in the desalination market in Saudi Arabia. The heat lost by the first-effect is utilized in the second-effect to evaporate more saline water which then condensates on the inner surface of the outer tube of the second-effect and so on. Minimum condensation energy is subjected to the last effect causing considerable lower heat loss to the surrounding. Major findings of the present study showed a great opportunity for the enhancement of the double and triple-effect active tubular solar still performance more than that of the higher effects. The proposed device is expected to increase the freshwater productivity by 60.5%, 97.8% and 122.4% for double, triple and quadruple-effect TSS, respectively. The optimum number of effects is the double and the triple-effect due to having the lower cost ($0.007) of water production per liter.