Salinity gradient energy is not a competitive source of renewable energy

Abstract

In this perspective, we critically assess the competitiveness of salinity gradient energy (SGE) as a renewable energy source. While scientifically intriguing and gaining research attention, SGE encounters formidable challenges in competing with established renewable technologies, such as solar and wind energy. Even the most advanced SGE technology, pressure retarded osmosis, remains far from cost competitive, primarily because of its low energy density and conversion efficiency. These constraints appear to be fundamental, unlikely to be resolved solely through material or process advancements. While integrating SGE in applications such as energy storage or desalination has been actively explored, it still fails to present compelling value propositions in the context of their specific applications. Therefore, we strongly encourage the research community to critically examine the practical impacts of research aiming to advance the technical aspects of SGE.