Concept for energy harvesting from the salinity gradient on the basis of geothermal water

Abstract

The use of renewable energy resource is usually directed to solar, wind or hydroelectric stations. However, there are other sources for getting the ‘green energy’. One of them is geothermal source, the energy stored in the underground fluids. In the world, geothermal water is used mostly for heating purposes, greenhouses, agriculture, for generation of warm water, therapeutic and recreational purposes and to generate electricity in power stations. After these uses, geothermal water is usually seen as waste water. This research presents the idea for innovative energy harvesting from the salinity gradient on the basis of waste geothermal water. Two methods are analyzed to be used: capacitive mixing (CAPMIX) and reverse electrodialysis (RED). The aim of the research concept is analysis for testing the applicability of both methods in energy harvesting from mixing of saline geothermal water and RO brine with water, before its re-injection to underground reservoirs.