“…Several technologies have been researched to extract energy from salinity gradients, [3], but doubtless pressure-retarded osmosis (PRO) is the technique which has emerged as the most promising technology, [4]. Although many configurations for a PRO system have been proposed, for example, concepts in which osmotic power production is attained by pressurizing the fluid rather than increasing volumetric flow, [5], or concepts related with the design of the module configuration of the PRO membrane, [6] as well as alternative applications, [7], [8], however, for illustration purposes, the most simple PRO system depicted in Fig. 1 seems preferable.…”