Use of RES-powered desalination in water-stressed regions. A case study in Algarve, Portugal

Gil Azinheira; Raquel Segurado; Mário Costa

Key information

Authors:

Gil Azinheira (Gil Emanuel Pastor Azinheira); Raquel Segurado (Raquel Inês Segurado Correia Lopes da Silva); Mário Costa (Mário Manuel Gonçalves da Costa)

Published in

2022

Abstract

With a severe seasonal concentration of precipitation, unevenly distributed water resources, and frequent droughts and floods, the water supply in Portugal is under stress, and the problem is expected to increase with climate change. Water desalination is increasingly becoming the preferred solution to fight water scarcity, but being energy-intensive, the underlying costs and sustainability concerns over the power sources chosen remain a challenge to its implementation. This study aims to assess if the introduction of renewable energy sources (RES)-powered seawater desalination in mainland Portugal is viable and can contribute to guarantee water security. The Portuguese Algarve region was chosen as a case study because it is particularly water-stressed and subject to highly varying demographics depending on the season. Two strategies are considered: either one large plant supplies the whole region (centralized), or two smaller ones supply their respective subregions (decentralized). Taking the region’s freshwater demand, hourly RES production, and power demand, a cost analysis is performed in order to obtain an estimation for the produced levelized cost of water (LCOW). Two models were developed to estimate the LCOW: a simplified model and a subsequent optimization model, minimizing electricity costs. The resulting 72.66 c€/m3 of desalinated water, obtained for the decentralized solution, fits within the industry standard rate although being 61.3% higher than the estimated conventional water supply production cost.