Technical and economical aspects of solar desalination with particular emphasis on solar pond powered distillation plants

Abstract

Desalination remains an important and interesting application for the use of solar radiation as a source of undepletable energy. After almost a decade of research and development including the installation and testing of various smaller pilot systems, our solar desalination technology - among others - is now becoming available on a commercial level. The paper discusses the evolution of the technology both of the desalination and the collector-subsystems as a result of the technical and economical constraints associated with the utilization of solar energy, a highly fluctuating energy source of low surface density. Performance data is presented in particular for the coupling of a selfregulating MSF unit with a solar pond energy collection and storage system, both inhouse developments. The performance and layout data was obtained both from computer simulation and experimental results with a small sized solar pond and desalination subsystem in Switzerland. The economy assessment, which is presented for Middle East climate conditions, clearly demonstrates that solar desalination already becomes competitive for medium sized installation at remote locations. Potential further cost reductions also through upscaling may lead to the use of desalinated water for agricultural applications one day.