Researchers at MIT and King Fahd University of Petroleum and Minerals in Saudi Arabia have improved feasibility for pressure-retarded osmosis (PRO) systems by reducing the size of the costly membrane. PRO relies on a difference in salinity between two water sources divided by a membrane, and the higher water level on the salty side can be used to run a turbine, generating clean and reliable energy. Future applications for PRO could include powering side-by-side desalination and wastewater treatment plants, but membrane size still needs to be scaled down further.
Source: WSJ