Stanford engineers invent high-tech mirror to beam heat away from buildings into space

[OKIsItJustMe]

7. As I recall, they take clouds into account

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Using engineered nanophotonic materials the team was able to strongly suppress how much heat-inducing sunlight the panel absorbs, while it radiates heat very efficiently in the key frequency range necessary to escape Earth’s atmosphere. The material is made of quartz and silicon carbide, both very weak absorbers of sunlight.

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http://pubs.acs.org/doi/abs/10.1021/nl4004283

[font face=Serif][font size=5]Ultrabroadband Photonic Structures To Achieve High-Performance Daytime Radiative Cooling[/font]

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[font size=4]Abstract[/font]
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If properly designed, terrestrial structures can passively cool themselves through radiative emission of heat to outer space. For the first time, we present a metal-dielectric photonic structure capable of radiative cooling in daytime outdoor conditions. The structure behaves as a broadband mirror for solar light, while simultaneously emitting strongly in the mid-IR within the atmospheric transparency window, achieving a net cooling power in excess of 100 W/m2 at ambient temperature. This cooling persists in the presence of significant convective/conductive heat exchange and nonideal atmospheric conditions.

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