Rivers Could Generate 2,000 Nuclear Power Plants Worth of Energy With ‘Blue’ Membrane

sciencehabit shares a report from Science Magazine: Green energy advocates may soon be turning blue. A new membrane could unlock the potential of ‘blue energy,’ which uses chemical differences between fresh- and saltwater to generate electricity. If researchers can scale up the postage stamp — size membrane in an affordable fashion, it could provide carbon-free power to millions of people in coastal nations where freshwater rivers meet the sea. Blue energy’s promise stems from its scale: Rivers dump some 37,000 cubic kilometers of freshwater into the oceans every year. This intersection between fresh- and saltwater creates the potential to generate lots of electricity — 2.6 terawatts, according to one recent estimate, roughly the amount that can be generated by 2,000 nuclear power plants. By pumping positive ions to the other side of a semipermeable membrane, researchers can create two pools of water: one with a positive charge, and one with a negative charge. If they then dunk electrodes in the pools and connect them with a wire, electrons will flow from the negatively charged to the positively charged side, generating electricity.