Food, water and power from thin desert air
Wavelength-selective agrivoltaics are here: solar panels that are transparent in the wavelengths chlorophyll can use, while generating electricity from other wavelengths. Meanwhile, the harvesting of water from even air people consider dry is an area of intensive development. Active systems use electric heat pumps to chill surfaces on which dew then collects -commercialized by companies such as Watergen. More intriguing are passive harvesters. One recently developed in Switzerland manages to chill itself by enhanced infra-red radiation. In Shanghai, Dr. Ruzhu Wang's team has developed salt-infused hydrogels that pull in water at night, and release it when heated by the sun Put these together, and you can build greenhouses that meets their own needs - and more - without access to a power grid, or any supply of liquid water. Arid sunny places are seen through new eyes. Namibia, for example (where moist air rolls in each night and there are beetles that perch on the tips of dunes, allowing dew to form on their own bodies); or the Atacama desert, the Sinai peninsula, or waterless islands like the Galapagos. China - with huge expanses of arid land, not considered arable - is on the case. When economies of scale are brought to bear on the elements of these systems, desert towns that make their own food, water and power from what the desert offers in abundance seem destined to spring up like mushrooms.