Abstract
Recent studies in passive solar-driven evaporative technologies have introduced a plethora of new materials and devices which promise higher economic and environmental sustainability in water treatment. However, many challenges remain for the effective adoption of such technologies. Here, we identify three main pillars and the corresponding issues which future research activities should focus on to bring the proposed solutions to the next maturity level. Specifically, our analysis focuses on standards for comparing productivity, strategies to overcome the single stage limit, scalability and robustness.