Abstract
With 50% of humanity living along coastal areas, ensuring reliable and affordable access to freshwater in these communities becomes crucial. Securing such access to freshwater not only enhances the resilience of coastal communities during emergency situations like natural disasters but also sustains remote coastal areas with limited water infrastructure. Due to the growing issue of climate change, it is also critical to do this in a sustainable manner with minimal environmental footprint. This study proposes a novel design for a portable, modular, wave-driven reverse osmosis (RO) desalination device to provide water in these applications. The device consists of a point absorber wave energy converter (WEC), an RO membrane vessel, and a hydraulic power take-off (PTO) system. The PTO system uses a rotating chainwheel and arm to transmit the heave motion of a buoy to drive the lever of a hydraulic pump that pressurizes water for reverse osmosis. The design is specifically aimed to address emergency situations and remote coastal communities and improve over current designs. Since rapid deployment of the device is paramount to save lives in an emergency situation, the device is highly portable, weighing under 30 pounds with all the materials fitting inside a small box. This means the device is much easier and quicker to deploy compared to current designs, which typically weigh several hundred pounds. The portability is achieved through the use of modularity, as well as inflatable components, namely the buoy and counterweight. Similarly, mooring systems, commonly used in the wave energy industry, are impractical for both emergency situations and remote coastal communities as they require divers and special equipment to install, making the process time-consuming and costly for a small device. To address this, the device leverages near-shore infrastructure, such as pier and jetty columns, to achieve relative motion, negating the use of mooring. Lastly, since the device is implemented near-shore, the produced water is much more convenient and easy to collect compared to many off-shore, floating designs. The proposed system’s power and water output are analyzed using WEC-Sim and validated with preliminary calculation results. Additionally, a techno-economic analysis is conducted to find operating and capital expenses. Results indicate that the device can 163-216 liters per day, enough to support the basic daily water usage of 11-14 individuals in a remote coastal community or the drinking needs of 44-58 individuals in an emergency situation. At 10,000-unit production, the device’s capital cost of $163 and the LCOW (levelized cost of water) of $0.01/L, the device is highly affordable. Overall, the proposed device provides a novel and improved wave-powered desalination solution for emergency situations and remote coastal communities, and analysis results demonstrate its feasibility and significant potential in these applications.