Techno-economic assessment of vertical axis wind turbine driven RO desalination with compressed air energy storage for remote communities
Khalid M. Alzahrani, J. Hee, Mohamed Elsakka, D.B. Ingham, Lin Ma, Mohamed Pourkashanian
Abstract
Renewable energy desalination is gaining much attention in remote off-grid communities facing challenges in accessing clean water. Typically, batteries ensure the continuous operation of small-scale renewable reverse osmosis (RO) desalination systems; however, they are expensive and have relatively shorter lifespans. This study investigates the implementation of a compressed air energy storage (CAES) system coupled with a vertical axis wind turbine (VAWT) to directly drive small-scale RO desalination, potentially replacing batteries and reducing energy conversions. A Simulink model was developed to simulate the performance of a VAWT-driven CAES operating RO units, adaptable for both technical and economic assessments. Parametric studies have identified the optimal configuration. The most cost-effective configuration, utilising eleven VAWTs and a pressure exchanger (PX), achieves a levelised cost of water (LCOW) of 1.63 US$/m 3 and an annual water production of 9400 m 3 . The normalised daily water production per square metre of turbine swept area at the study site is 0.19 m 3 /m 2 /day at an average wind speed of 5 m/s. While this configuration has a higher initial capital cost, it yields the lowest LCOW. The CAES system effectively addresses the intermittency challenges of wind energy. This study presents a novel, battery-free VAWT-CAES-RO system as a sustainable desalination solution for remote communities, offering a promising approach to address water scarcity in an environmentally friendly manner. • Using VAWTs to mechanically drive RO via a compressed air system was investigated. • Replacement of batteries with compressed air storage reduced water production cost. • VAWT with a compressed air system is economical, addressing wind intermittency. • Examined scenarios with varying VAWT numbers with or without energy recovery for the study site. • Parametric studies resulted in an optimal LCOW of 1.63 US$/m 3 for an off-grid system.