A thermal seawater desalination plant which utilizes waste heat from flue gases upstream, flue gas desulphurization (FGD), is discussed. This type of "low-grade" heat is suitable for low-temperature desalination technologies such as multi-effect distillation (MED) technology. Two different alternatives for using the heat is analyzed and compared. In these schemes, about 8,500-10,000 m(3)/d of high-quality water (similar to 10 mg/l TDS) may be produced from one 575 MW generating unit. Moreover, a great amount of water is saved due to reduction in flue gas temperature and therefore reduction in water evaporation in the flue gas scrubber. An economics evaluation of the alternatives is presented. The water cost obtained is in the range of 53-62 US cent/m(3) and depends on the MED and gas cooler capital costs, unit capacity factor and required rate of return. The obtained costs are comparable to water cost obtained from state-of-the-art, large-scale sea-water reverse osmosis (SWRO) plants even without taking into account the higher water quality.