Effects of water pretreatment on the extractable salinity gradient energy at river mouths: the case of Magdalena River, Caribbean Sea

• Published in: Journal of ocean engineering and marine energy Vol. 5; no. 3; pp. 227 - 240
• Main Authors: Alvarez-Silva, Oscar, Maturana, Aymer Y., Pacheco-Bustos, Carlos A., Osorio, Andrés F.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.08.2019; Springer Nature B.V
• Subjects: Coastal Sciences; Design flow; Electric power generation; Energy; Energy consumption; Energy harvesting; Engineering; Engineering Fluid Dynamics; Formulations; Mechanical Engineering; Membranes; Natural resources; Natural waters; Oceanography; Offshore Engineering; Power consumption; Power plants; Pretreatment; Pretreatment of water; Renewable and Green Energy; Research Article; River mouth; River mouths; Rivers; Salinity; Salinity gradients; Magdalena River; Salinity gradient energy; Magdalena River mouth; Water pretreatment; Design flow; Water quality
• ISSN: 2198-6444; 2198-6452
• DOI: 10.1007/s40722-019-00141-y

River mouths are locations with high theoretical potential for harvesting salinity gradient energy (SGE) since waters of different salinities are abundant in these places. However, the net extractable SGE potential—or site-specific potential (SSP)—is determined not only by the available natural resources but also by the energy consumption required for operating the power plant. Particularly, the required inputs for water pretreatment prior to energy generation to preserve the proper functioning of the membranes and other components within the systems, have been identified as a major drawback for SGE generation from natural waters. In this paper, the required energy consumed during water pretreatment was estimated, comparing conventional and membrane-based methods. This energy input was included in the formulations of the SSP, as a function of the design flow of the power plant and was used to assess the extractable SGE potential at the Magdalena River mouth, a top-ten system for SGE generation worldwide. The results showed that water pretreatment produced an important reduction of the SSP in the case study, while high potentials were still found for appropriate design flows.