The national programme for sea water desalination in Saudi Arabia is assigned to the Saline Water Conversion Corporation (SWCC), a government entity loosely affiliated with the Ministry of Agriculture. In addition to water production, SWCC generates considerable electric power in its dual purpose power/water plants, selling excess power to the national grid. SWCC also builds and maintains certain major fresh water pipelines that connect its plants to important municipal water systems. SWCC's pride is the Research, Development and Training Center (RDTC) located in Al-Jubail. The goals at RDTC include improving plant efficiency and minimizing scale formation and corrosion problems. It also trains Saudi engineers and technicians in the operation and management of SWCC plants. As a result, Saudi nationals now represent 65% of the workforce and are heavily involved with all aspects of plant specification and tender analysis. Working at the plant site, SWCC has been able to optimize the power/water production ratios to minimize the cost of base load plants; use multi-stage flash (MSF)/reverse osmosis (RO) hybrid plants to further reduce water costs; optimize the selection and design of materials; make improvements in the process of site selection and intake design; reduce operation and maintenance costs through the field testing of new process concepts; continue the development and training of plant operators; use local workshops and suppliers whenever possible; field test new products, processes and materials; and, in total, reduce water costs to as low as US $0.53/m(3). Looking to the future, SWCC is aware that it must adopt new policies with respect to pricing and consider the long term implications of subsidized water. It also recognizes that desalination costs will continue to decrease because of economies of scale; use of lower cost materials; more efficient operation; increased use of automation and sophisticated controls; and continuing high competition among suppliers. All these points are, of course, of benefit to the eventual customer. In terms of technical developments, MSF is mature and will see only incremental improvements in cost and performance. Multi-effect distillation (MED) and thermal vapour compression (TVC) are still developing towards larger unit sizes, better efficiency and greater reliability. RO will continue to advance through longer operating histories from which to learn; improved pretreatment techniques, including membrane pretreatment; and improved membranes with lower operating pressures, a higher flux and higher salt rejection. Overall, 50% water recovery will become the norm. Beyond this, new versions of hybrid plants will appear, including membrane/membrane membrane/adsorption and membrane/electrochemical systems. The eventual result will be plants with 100% recovery (zero discharge). The prospects for desalination with nuclear energy are bright, but it must be remembered that most coupling options are not unique to nuclear. Social and political issues are critical and must be addressed early and often. It can be concluded that sea water desalination is now reliable and of reasonable cost; desalination costs will continue to decrease; MSF is close to optimization; MED and TVC are growing in competitiveness to MSE especially in smaller sizes; RO continues to strengthen as a viable candidate under nearly all conditions; the final choice of technology should be reached by an educated customer, not dictated by suppliers; and international co-operation is vital to the further productive reset that is so critical to success.
