This report is the result of work carried out by the IDAE with the objective of defining the most suitable technique from an energy point of view for desalinating water using movable plants, which can be transferred from one site to another. Since the energy consumed in technologies available for desalinating seawater is electricity alone in reverse osmosis, and heat and electricity in distillation technologies (the proportion of which varies according to whether the VVC or MED process is employed), there is an opportunity to make simultaneous use of the electricity and heat produced in all electricity generation, although they can only be applied in distillation technologies and where the plant is designed to operate with a careful combination of the RO and distillation technologies. This optimization of energy can be achieved in all types of plants (permanent or movable), but it is of particular interest in the case of the movable plants because it makes the plant independent with regard to its energy consumption. In short, the plant does not depend on the national electricity network system. This independence offers advantages which will be studied later on. Indeed, the aim of this report is to describe the movable maximum energy efficiency plant and to analyze the costs of the same in comparison with other alternatives.