Local cost of seawater RO desalination based on solar PV and wind energy: A global estimate

This study demonstrates how seawater reverse osmosis (SWRO) plants, necessary to meet increasing future global water demand, can be powered solely through renewable energy. Hybrid PV–wind–battery and power-to-gas (PtG) power plants allow for optimal utilisation of the installed desalination capacity, resulting in water production costs competitive with that of existing fossil fuel powered SWRO plants. In this paper, we provide a global estimate of the water production cost for the 2030 desalination demand with renewable electricity generation costs for 2030 for an optimised local system configuration based on an hourly temporal and 0.45° × 0.45° spatial resolution. The SWRO desalination capacity required to meet the 2030 global water demand is estimated to about 2374 million m3/day. The levelised cost of water (LCOW), which includes water production, electricity, water transportation and water storage costs, for regions of desalination demand in 2030, is found to lie between 0.59 €/m3– 2.81 €/m3, depending on renewable resource availability and cost of water transport to demand sites. The global system required to meet the 2030 global water demand is estimated to cost 9790 billion € of initial investments. It is possible to overcome the water supply limitations in a sustainable and financially competitive way. © 2016 Elsevier B.V. All rights reserved.

An energy model is used to estimate the viability of meeting the 2030 global water demand, based on the optimistic scenario, solely with SWRO plants powered by renewable energy. Hybrid renewable energy power plants are used as they offer higher full load hours and therefore allow for better utilisation of the desalination plant capacity. The 2030 costs for different renewable energy technologies are used. The least cost system is found to be a combination of fixed-tilt PV, single-axis tracking PV, wind energy, batteries and PtG power plants. The LCOW range is predominantly between 0.70 €/m 3 – 2.00 €/m 3 .The current LCOW range of fossil powered SWRO plants, excluding water transportation, is between 0.60 €/m 3 – 1.90 €/m 3 . Therefore, in the near future, SWRO plants powered by renewable energy will produce water at similar prices to that of today's fossil plants. Furthermore, depending on the terrain, the water transportation costs can contribute significantly to the final LCOW.