Salinity gradient energy harnessing at river mouths. From theoretical to extractable resources

Abstract: salinity gradient energy (SGE) is the clean and renewable energy that can be obtained from controlled mixing of two water masses with different salt concentration. River mouths, where fresh water mixes with saline seawater, are manifest locations for harnessing SGE, since provide the sought salinity gradients and abundant water resources worldwide. Most of the research in SGE has been focused on improving the performance of the energy generation techniques; however, as these techniques reach higher stages of development, more attention must be paid to the challenges that harnessing SGE from natural systems will bring. This thesis addresses persistent gaps on the research of suitability, available potentials and extractable resources of SGE at river mouths. These topics are approached at global and local scales from three strategies: hydrodynamic modelling of temporal and spatial variability of the salinity structure of river mouths; analysis of databases of variables and resources related with SGE at river mouths; and parameterization of the physical relations among environmental forcings, stratification and SGE potentials. The results of this research show that only river mouths with mean tidal range lower than 1.2 m are suitable locations to generate SGE; 20% of the mean discharge of rivers may be extracted for SGE generation; harnessing SGE at river mouths is very reliable with average capacity factor of 84%; and 625 TWh/y of SGE are extractable from river mouths worldwide considering site-suitability and environmental constraints. But beyond these numbers, most important contributions of this thesis are: development of the concept of site-specific potential for more precise assessment of the SGE resources at river mouths; description of the relation between stratification and SGE potential; classification of river mouths according to the suitability for harnessing SGE; mapping of the global distribution of available SGE resources; proposing a methodology to assess extractable SGE resources from particular systems; and overall discussion of physical and environmental constraints for SGE generation at river mouths. Together, these findings constitute a significant progress in the study of opportunities of harnessing SGE at river mouths in the upcoming future

• Autores: Alvarez Silva, Oscar Andrés
• Tipo de recurso: Doctoral thesis
• Fecha de publicación: 2015
• Institución: Universidad Nacional de Colombia
• Repositorio: Universidad Nacional de Colombia
• Idioma: spa
• OAI Identifier: oai:repositorio.unal.edu.co:unal/54191
• Acceso en línea: https://repositorio.unal.edu.co/handle/unal/54191; http://bdigital.unal.edu.co/49046/
• Palabra clave: 55 Ciencias de la tierra / Earth sciences and geology; Tidal power; Renewable energy sources; Saline water conversion; Energía maremotriz; Recursos energéticos renovables; Conversión de aguas salinas
• Rights: openAccess
• License: Atribución-NoComercial 4.0 Internacional