Economic evaluation of stand-alone solar powered membrane distillation systems

Economic evaluation was carried out to understand the main contributors to water production cost in solar-powered membrane distillation (SP-MD) systems. Three SP-MD systems (Direct Contact (DCMD), Air Gap (AGMD), and Vacuum (VMD)) were modeled and economically analyzed. A parametric study was conducted on the AGMD, the most frequently used SP-MD configuration, to understand the relationships between various design and operation parameters and water production cost. The parametric study results show that, in the AGMD system, increasing the feed inlet temperature had a significant effect in lowering the cost while higher feed flow rate resulted in increased water production cost. This study also shows that higher effective membrane length and lower air gap width and feed channel depth reduce the cost of water. Finally, the choice of MD configuration (AGMD, VMD, DCMD) in SP-MD systems will impact the final water cost.

► Solar-powered membrane distillation (SP-MD) systems were studied from economic viewpoint.
► Three SP-MD configurations were considered; AGMD, VMD and DCMD.
► Study starts by modeling the performance of a typical SP-MD system, then doing the cost analysis.
► Impact of several SP-MD system design and operation parameters on production cost were evaluated.
► Study makes several suggestions to reduce water production cost via SP-MD.