Volume 23: Sustainable Energy Solutions for a Post-COVID Recovery towards a Better Future: Part VI

Integrated Pumped Hydro Reverse Osmosis System Optimization with Enhanced Reverse Osmosis Modeling Matthew W. Haefner, Maha N. Haji

Abstract

The pressure head generated by the upper reservoir of a pumped hydro energy storage system located at 500-700m elevation can also be sufficient for creating the pressure gradient required for a reverse osmosis desalination plant. Combined with the fact that many drought-stricken coastal areas have nearby mountains at the necessary elevation for these upper reservoirs, a symbiotic relationship can be ascertained through the co-location of a pumped storage hydropower (PSH) system with a reverse osmosis (RO) desalination system. Merging PSH and RO into one Integrated Pumped Hydro Reverse Osmosis (IPHRO) system [1] instead of implementing each individually could result in a number of benefits, including reduced capital investment, lower maintenance costs, and a natural mechanism for diluting the highly saline brine discharge generated from the RO process. This paper extends the work of Slocum et al. in 2016 [1], who first introduced IPHRO systems, by optimizing the amount of seawater diverted from the upper reservoir for energy recapture and fresh water production, respectively. For this multi-objective optimization, a new reverse osmosis model is created that utilizes a blend of empirical and fundamental equations based on the solution-diffusion model of membrane transport and boundary layer effects that naturally occur along reverse osmosis membranes. Doing so presents an attempt to increase the fidelity of the IPHRO system simulation model to better represent real-life scenarios, which will eventually aid in the IPHRO system’s large-scale adoption into energy and freshwater infrastructures.

[1] Slocum, A. H., Haji, M. N., Trimble, A. Z., Ferrara, M., & Ghaemsaidi, S. J. (2016). Integrated Pumped Hydro Reverse Osmosis Systems. Sustainable Energy Technologies and Assessments, 18, 80–99. https://doi.org/10.1016/j.seta.2016.09.003

Keywords Integrated Pumped Hydro Reverse Osmosis System, reverse osmosis, multidisciplinary design optimization, solution-diffusion model, concentration polarization