Integrated seasonal pumped hydro, cooling, and reverse osmosis: A solution to desert coastal regions

Matching the supply of renewable energies with electricity demand, providing cooling services and desalinated water are main challenges faced by desert regions. One solution for the increase in variable renewable sources in the grid is seawater-based pumped hydro storage (PHS) located near mountainous coastlines. However, the widespread adoption of this technology is limited due to the added costs associated with corrosion and safeguarding against seawater intrusion, which can outweigh the advantages of not using freshwater with a lower reservoir. Nevertheless, when contemplating seasonal storage, the use of seawater in PHS plants becomes substantially more compelling. This paper accordingly integrates seasonal pumped hydro storage, seasonal thermal energy storage, and reverse osmosis, so that the same pump and motor is used for storing energy and desalinating seawater. Results presented in this paper are based on the two proposed projects and show that the levelized cost of storage for the projects investigated is 23 and 45 USD/MWh, which is similar to the cost of solar power. In conclusion, integrated seasonal pumped hydro, cooling, and reverse osmosis could be a viable alternative to desert coastal regions.