Estuaries could harvest ‘blue energy’

TECHNOLOGY

Engineers from Rutgers University in the US have paved the way for harvesting ‘blue energy’ wherever river water flows into an ocean. Blue energy is generated by positive sodium ions flowing from a container with salt water through a membrane and into a container with fresh water, as the membrane holds back the negative chlorine ions. The result is a voltage difference between the two containers, which can generate electricity by connecting electrodes in a circuit.

Previously scientists have created membranes full of boron nitride nanotubes through which the ions could flow, but these have not proven sufficiently efficient. The need is to make the nanotubes sit closely together and perpendicular to the surface