Recent trends and challenges in applications of
INTRODUCTIONAdequate and dependable fresh water resources are major issues confronting many nations worldwide (Maila, 2006;Goosen et al., 2011aGoosen et al., & 2011bHuang, 2010; Lund, 2007; Mahmoudi et al., 2010a Mahmoudi et al., & 2010b. With the world's energy demand increasing much research has been directed at overcoming these challenges and in particular in using renewable energy to help meet the power needs for water desalination (Huang, 2010; Lund, 2007; Mahmoudi et al., 2010a;Serpen et al., 2010). However, Goosen (2012) and Gottinger and Goosen (2012) argued that while development opens up and advances economies, and creates new wealth, millions are forced to struggle to make meaning of the darker side of development that is not environmentally sustainable. In the past, the world's ecosystems (i.e. air, land and water) were able to absorb the environmental damage resulting from extensive industrialization and development. Nevertheless, with the rapid increases in global population and industrialization, as well as enhanced demands on natural resources such as fresh water supplies, the earth is no longer able to sustain a healthy and balanced ecosystem (Laboy-Nieves, 2009; Laboy et al., 2009; Mahmoudi et al., 2010a Mahmoudi et al., , 2010b Misra, 2000). The sustainability of the society in which we live is determined not only by technical and economic progress, but also by environmental management (Abdulla et al., 2009; Gottinger and Goosen, 2012; Laboy et al., 2010; Maila, 2006). Sustainable development using more renewable energy sources, by improving energy efficiency and reducing water demand and waste production is now considered by many as being the model to follow (Goosen et al., 2004; Goosen, et al., 2009aGoosen, et al., , 2009b Misra, 2000). Elimelech and Philip (2011), for example, reported on the possible reductions in energy demand by desalination technologies, and the role of innovative technologies in improving the sustainability of desalination as a technological solution to global water shortages ( Figure 1). They argued that future research to improve the energy efficiency of desalination should focus on, for example, the pre-treatment and posttreatment stages of seawater reverse osmosis (SWRO) plants. Furthermore, Peñate & García-Rodríguez (2012a) presented a comprehensive review of the main innovations and future trends in the design of SWRO desalination technology with an emphasis on improving process performance and efficiency. They concluded that desalination with renewable energies is an attractive combination that will help to reduce stress on existing water supplies.The economic potential and environmental benefits of renewable energies, such as geothermal, solar, wave and wind, and their applications to reducing overall energy requirements have been described in a number of recent articles (Cataldi, et al., 1999;Huang, 2010;Goosen et al., 2011b; Lund, 2007; Mahmoudi et al., 2010a;Serpen et al., 2010;Stefansson, 2005)....