“Salt water and sunlight can yield food and clean water in a self-sustaining cycle. … One cubic metre of fog can contain up to 0.5 grams of liquid water, and harvesting it is relatively easy.” (http://www.nature.com/news/the-parched-planet-water-on-tap-1.15411)
Ingenious careers in aquatic abstraction: sea sweating and fog wringing.
Glass “made from niobium oxide, which darkens when exposed to current,” and coated with “nanoscale crystals of indium tin oxide” which absorb heat-producing radiation when exposed to current, allows electrical control of the light and heat transparency of windows. (http://www.nature.com/news/smart-glass-blocks-heat-or-light-at-flick-of-a-switch-1.13558)
Electrified windows won’t have a fingerprint problem either.