Duc Thuan Bui

1. Introduction Since the late 20th century, there has been an increase in global energy consumption and, as a result, an increase in CO2 emissions. In the last few decades alone, building energy demand in developed countries has risen to around 40% of total urban energy demand [1,2,3].

Kim et al. (Reports, 28 April 2017, p. 430) presented results for the solar-driven harvesting of water from air via metal-organic frameworks as a prodigious potential advance toward remedying global water shortages. Basic thermodynamics and a survey of multiple off-the-shelf technologies show that their approach is vastly inferior in efficiency (and thereby in feasibility) to available alternatives.