In this work a mathematical model is assembled to evaluate the electric complex power and electric current output of pressure retarded osmosis (PRO)- based generation plants. Unlike other works already reported in the literature, the assembled model allows performing that evaluation in the abc reference frame based on the salinity concentrations of the salty and fresh water bodies entering the membrane modules and the phasor voltages at the terminals of the generation plant. The induction generator is selected as the power transductor. The assembled model also collects main phenomena affecting the PRO process efficiency: internal concentration polarization, external concentration polarization and spatial variations. A numerical example is presented where the model is used to evaluate the electric complex power output of the PRO generation plant. The numerical results obtained suggest that reactive power compensation may be needed for the selected power transductor. These results also confirm that the main phenomena affecting the PRO process efficiency substantially affect the active power production, but not the reactive power consumption. In this way, the assembled model may be used to analyse the steady state performance of electric networks under the integration of PRO generation plants.

Pressure retarded osmosis (PRO) power units, which produce electrical energy from salinity gradient sources located at coastlines, are a technology still in the process of maturation; however, there is an expectation that this technology will need to be integrated into electrical distribution networks. Such integration will drive changes in the electric response of the distribution systems which may lead to harmful operating conditions. Power flow analysis is a tool used to reveal the steady-state operating condition of distribution systems and which could be extended to study and address the integration of PRO power units. To the best of the authors’ knowledge, such extension of power flow analysis has not yet been addressed in the literature. Accordingly, this paper comprehensively provides a model to evaluate the electric current and complex power produced by PRO power units. This model is directly embedded in the forward-backward sweep (FBS) method, extending the power flow analysis of electric distribution systems in this way so as to consider the integration of PRO power units. The resulting approach permits revealing of the steady-state operating response of distribution systems and the effects that may be driven by the integration of PRO power units, as corroborated through numerical results on a 14-node test distribution system.