McGill team develops hybrid membrane that could enable osmotic (blue) energy systems Osmotic energy—also known as blue energy—capitalizes on the energy naturally released when two solutions of different salinities mix—conditions that occur in countless locations around the world where fresh and salt water meet. The key to capturing blue energy lies in selectively permeable membranes, which allow only one constituent of a saltwater solution to pass through—either the water molecules or the dissolved salt ions—but not the other. To date, large-scale blue energy projects such as Norway’s Statkraft’s osmotic power plant at Tofte, Norway, have been impeded by the poor efficiency of existing membrane technology. Statkraft shelved its osmotic effort in 2014, saying that the technology could not be developed within the then current market outlook to become competitive within the foreseeable future.