Energy is one of the critical resources determining the overall socioeconomic development. Global warming and natural resource demand had made the world to look into renewable energy like solar, wind, and fuel cells. Salinity gradient energy is the concept of extraction of energy from the concentration gradient between saline and clean solution. In this review, we present different novel systems to generate electricity by salinity gradients by reverse electrodialysis technology integrated with capacitive electrodes and also different types of reverse electro dialysis. This capacitive reverse electrodialysis system synergistically combines previous developments in capacitive mixing and reverse electrodialysis. This review work consists of the study of various reverse electrodialyses, comparing the recent advancements with the novel process and integrates the various results and experiments, and reviews of all reverse electrodialysis are incorporated.