Energy performance of a reverse osmosis desalination plant operating with variable pressure and flow

•We show the technical feasibility of the variable operation of RO plants.•No membrane deterioration was observed over the course of the test period.•The system adapts perfectly to the variability of the energy supplied.

Recent studies and projects have shown that a combination of a reverse osmosis desalination plant with a wind power supply is technologically feasible if the plant operates with fluctuating and intermittent loads and in this way follows the variable energy supply characteristic of a wind turbine. The direct integration of renewable energy into a reverse osmosis plant is described in this paper, as well as its relation with energy consumption as a consequence of the plant working under variable load conditions. The data obtained confirm the wide operating range of the plant with respect to the power available and the system specifications.Experimental results are shown for different operating regimes, with significant data being obtained for the reverse osmosis process. The development of systems as described in this paper opens up a range of possibilities for expansion due to their excellent characteristics in terms of the new concept of plant operation at different pressures and flow rates along with the use of water production storage. According to the results shown in this paper, optimum plant performance was observed for a power input approximately 20% lower than the design specifications.