Abstract
The combination of tidal energy and seawater desalination has several advantages, including a low carbon footprint, high reliability and stable energy output. The technical and economic challenges for such integration are not unique to tidal energy technologies, for example in the field of wind energy several advances have been made in the integration of desalination systems with horizontal axis turbines as has been presented in. One of the practical advantages of using hydrokinetic turbines, is the lower power ratings compared with wind turbines which allow to use off-the shelf hydraulic components. At the same time the high pressure pumps are already located under water so there is no need for priming the seawater flow. Tidal energy for seawater desalination is a promising area of research that could help meet the growing demand for clean drinking water in coastal regions and for off-grid applications. This extended abstract presents part of the numerical results of an innovative direct-driven tidal desalination system with energy recovery device, where a single unit is evaluated for different recovery rates operating in the below rated variable speed region.
In this work three cases are analysed, where the recovery rate of the ERD device is capped to the maximum values of 50%, 60%, and 100%. The latter case corresponds to an ideal operation of the ERD where no constraints are imposed and the boost pump is able to deliver the required flow to achieve the desired recovery rate for ideal variable speed operation of the rotor.