Photovoltaics powered seawater desalination by reverse osmosis and water conveyance benefits the green energy transition in the Middle East

Abstract

Despite the clear benefits, powering large-scale desalination plants and water conveyance by renewable energies is not yet established. In particular, the combination with photovoltaics presents a promising option due to significant cost reductions and the predictable power output in sun-rich countries. This study investigates the technical limits and economic feasibility of variable-operated seawater reverse osmosis desalination and water conveyance operated according to the photovoltaics power profile in Jordan. We analysed suitable operating modes based on the membrane element's safe operating window and determined their power demand profile for energy balancing and economic evaluation. The study results indicate that keeping the concentrate flow constant is the most appropriate desalination operating mode for large-scale implementation. Desalination and water conveyance from Aqaba to Amman, operated following the photovoltaics power profile, cost approximately 2.5 $/m³ at 46 % water production availability, compared to 1.8 $/m³ in full-load operation with a 46 % photovoltaic power share. Furthermore, raising the photovoltaic power share to 72 % is achievable with time-varying water pumping, where each 1 % increase in photovoltaic power share adds about 0.02 $/m³. Variable-operated seawater desalination and time-varying water pumping allow flexible renewable energy utilisation by shifting load and water capacities, advancing the green energy transition by 2050.