Salinity Gradient Power: An overview of applications and experiences

A huge potential to obtain clean energy exists from mixing water streams with different salt concentrations. Salinity gradient power (SGP) is based on thechemical potential difference between concentrated and dilute salt solutions. In This paper we discus about typical applications and experiences forpressure retarded osmosis (PRO) systems that is a kind of SGP systems, summarizing the current state of PRO technology at the pilot and industrialscale, and discussing future perspectives for salinity gradient energy from PRO. The first PRO configuration explored has been river-to-sea water andalthough this configuration has the potential to be a reliable source of baseload renewable energy, the low-energy density associated with this salinitygradient makes commercialization of PRO in this configuration unlikely. Additional PRO configurations include reverse osmosis (RO)–PRO. Thehigher salinity gradient available for power production in RO–PRO systems is likely to make them a more promising component of an alternative energyportfolio.

Keywords:

Pressure Retarded Osmosis (PRO) , Salinity Gradient Power (SGP) , Membrane.