Salinity gradient energy of 109 first-class water systems in Japan

Salinity gradient energy (SGE) is the physico-chemical energy released from an aqueous solution when freshwater is mixed with salt water. SGE is expected to be an alternative energy source that is not affected by weather or time of day, especially near estuaries, where large amounts of water can be taken from rivers and the sea. In this study, we theoretically evaluated the SGE potential and electric power available in 109 major rivers in Japan to identify suitable locations for SGE applications. Furthermore, we examined the usefulness of SGE by comparing the amount of electric power extractable from SGE to that obtained from other power generation methods. • Estimated the salinity gradient power (SGP) available at 109 estuaries in Japan • Compared the SGP values to existing renewable energy output • Demonstrated theoretically the usefulness of SGP generation in Japan