By Ahmed S. Nada
Nobel Laureate in Chemistry, the late Richard Smalley, once ranked the "top 10 problems of humanity for the next 50 years". Interestingly, energy and water came in first and second on that list. His rationale for energy featuring at the top was that most, if not all, of the other problems could be either resolved or alleviated by the availability of affordable clean energy for all.
Affordable, clean energy and ready access to freshwater are also arguably two of the most pressing challenges for the Middle East. Studies suggest that, today, the average citizen in the region has access to a little over 1,000m3of renewable freshwater, as compared to a global average of over 7,000m3.In fact, according to the World Bank, 14 of the world's 20 most water-scarce countries are in the Middle East and North Africa (MENA) region. To further intensify the issue, experts estimate that domestic water demand will more than triple over the next three decades as a result of a growing population, rapidly developing urban economy and projected climactic changes.
To meet the rising water demands in a region that is typically arid, governments have turned to large scale desalination and wastewater treatment. Notably, the MENA region accounts for about 38% of global desalination capacity. While Egypt has historically relied on the Nile for its freshwater needs, it is rapidly ramping up its desalination capacity, in particular to supply the requirements for the nation's tourism industry and for power generation.
Desalination is typically the process of seawater or brackish water separation into a freshwater component and a brine concentrate. Desalination methods are predominantly of two types - thermal desalination which uses heat to vaporise freshwater, and membrane desalination or reverse osmosis (RO), which makes use of high pressure to separate freshwater from seawater, using a membrane. Reverse osmosis is now a mainstream desalination technique, primarily because it is more energy efficient than thermal, requiring only electricity to operate, while thermal also requires heat in addition to electricity.
In fact, the desalination process, by nature, is highly energy-intensive; in RO systems, energy consumption can account for almost 30% of the cost of desalinated water. Furthermore, when desalination is powered by hydrocarbons, whether the country consumes its own resources or imports fuel, the economic cost is significant.
SOURCE and rest of srticle: http://www.dailynewsegypt.com/2015/01/26/desalination-solar-solution/