Salinity differential (Gradient)  energy resource

Salinity differential (Gradient)  energy refers to chemical potential differential energy between seawater and fresh water, or seawater with different salt content, which is mainly present in the neighboring of river and sea. While the salt lake, which is fertile of fresh water and the underground salt mine, can also utilize its salt differential energy. Salt differential energy has been one of renewable energy with the largest power density in ocean energy. Generally, the chemical potential difference between seawater with the salt degree of 3.5% and fresh water equals the power density in 240 water head difference. Such potential difference can be realized in the neighboring of sea water and freshwater by utilization of semi-infiltration membrane in which can only flow water instead of salt. Electricity can be generated directly by turbine hydro generator by use of such water head difference.

It is theoretically estimated that the potential of salt temperature differential energy is in the scale of about 10¹⁰kW in the world and 1.1´10⁸kW in China, which is centralized in the marine outfall of each river. Moreover, some inland salt lake in Qinhai province can be utilized.