Decentralized Solar-Driven Photothermal Desalination: An Interdisciplinary Challenge to Transition Lab-Scale Research to Off-Grid Applications

Abstract

Sunlight can power thermal desalination as a carrier of electromagnetic energy if efficiently turned into heat. In the search for technologies to relieve global water scarcity, thermal desalination has key advantages in terms of sustainability, robustness, and limited salinity dependence. Solar-driven photothermal desalination (SDPD) can enable decentralized water purification, improved accessibility, and reduced environmental impact overcoming limitations of conventional, infrastructure-heavy desalination practices. However, there remains a lack of consensus on how to best evaluate the efficiency of diverse light-driven systems. While developing advanced absorbers, evaporators, and materials for desalination is essential, we have concluded that more efforts should focus on system-wide optimization, with particular attention paid to thermal energy recovery and loss mitigation. This Perspective offers a blueprint for achieving efficient and scalable SDPD under varying solar irradiation, emphasizing the need for interdisciplinary approaches to accomplish this goal.