Large-scale implementation of solar interfacial desalination

Abstract

Solar interfacial desalination (SID), a technology that uses solar energy to produce fresh water, is seen as a potential solution to the twin shortages of water and energy. However, there remains a big gap between the current bench-scale success and future industrial application. Here we show a scaled-up SID system that spans over 150 m2 and achieves a fresh-water production rate of up to 4.5 kg m−2 d−1 and a rated fresh-water productivity of 300 kg d−1 over 4 months of operation. Taking advantage of this large-scale system, we found that the system size requires a dramatic change in materials selection and a substantial increase in thermal mass, leading to a different water yield. A cost analysis revealed that capital investment is heavy, unlike the low-cost operation in indoor SID. We also underscore the importance of addressing fouling, including sedimentation and green algae. By combining a large-scale implementation with an analysis of an SID platform, this work offers insights into its potential for sustainable application in remote areas for domestic water supplies. Despite its enormous potential to address water scarcity, solar interfacial desalination remains at only the research level. Here the authors scale up its implementation and identify the key technical and cost issues that must be addressed to accelerate market adoption of this promising technology.