Sorption- and radiative sky cooling-based atmospheric water harvesting (AWH) technologies hold promise to provide decentralized fresh water in highly remote and arid regions. The recent emergence of advanced energy materials such as hygroscopic metal–organic frameworks, hydrogels and nanoporous composite sorbents, in addition to radiative sky cooling materials provided the necessary means for AWH. However, truly continuously operational devices are yet to be developed and field-tested. The research focus is now facing a paradigm shift, as future AWH systems are challenged to provide water generation on a kilogram scale, finally meeting a recommended daily water intake per person. This criterion can be adeptly met with continuously operated devices in comparison to discontinuous ones, providing much needed compactness alongside energy and mass efficiency. Here we critically discuss the drawbacks of current energy materials as well as system designs that hinder the use of continuous AWH. Based on identified challenges we outline viable scientific and technological paths. In addition, a possible synergistic effect of sorbents and radiative sky cooling materials on material and system levels to achieve 24 hour continuous fresh water generation is discussed. The provided development paths can spur voluminous avenues into sustainable continuous AWH exploration, making the ultimate goal “to provide fresh water for all” a step closer.

中文翻译：

---

可持续的水生产：连续大气水收集的巨大挑战

基于吸附和辐射天空冷却的大气集水 (AWH) 技术有望在高度偏远和干旱的地区提供分散的淡水。最近出现的先进能源材料，如吸湿性金属有机框架、水凝胶和纳米多孔复合吸附剂，以及辐射天空冷却材料，为 AWH 提供了必要的手段。然而，真正连续运行的设备还有待开发和现场测试。研究重点现在正面临着范式转变，因为未来的 AWH 系统面临着提供公斤级水生成的挑战，最终满足每人建议的每日水摄入量。与不连续的设备相比，连续操作的设备可以很好地满足此标准，提供急需的紧凑性以及能量和质量效率。在这里，我们批判性地讨论了当前能源材料的缺点以及阻碍连续 AWH 使用的系统设计。根据已确定的挑战，我们概述了可行的科学和技术路径。此外，还讨论了吸附剂和辐射天空冷却材料对材料和系统水平的可能协同效应，以实现 24 小时连续淡水生成。所提供的发展路径可以为可持续的连续 AWH 勘探提供大量途径，使“为所有人提供淡水”的最终目标更近一步。根据已确定的挑战，我们概述了可行的科学和技术路径。此外，还讨论了吸附剂和辐射天空冷却材料对材料和系统水平的可能协同效应，以实现 24 小时连续淡水生成。所提供的发展路径可以为可持续的连续 AWH 勘探提供大量途径，使“为所有人提供淡水”的最终目标更近一步。根据已确定的挑战，我们概述了可行的科学和技术路径。此外，还讨论了吸附剂和辐射天空冷却材料对材料和系统水平的可能协同效应，以实现 24 小时连续淡水生成。所提供的发展路径可以为可持续的连续 AWH 勘探提供大量途径，使“为所有人提供淡水”的最终目标更近一步。