Radiative cooling even in direct sunlight at the Equator? You betcha.
A Stanford team has designed an entirely new form of cooling panel that works even when the sun is shining. Such a panel could vastly improve the daylight cooling of buildings, cars and other structures by radiating sunlight back into the chilly vacuum of space.
First, the reflector has to reflect as much of the sunlight as possible.
The second challenge is that the structure must efficiently radiate heat back into space. Thus, the structure must emit thermal radiation very efficiently within a specific wavelength range in which the atmosphere is nearly transparent.
The Stanford team has succeeded where others have come up short by turning to nanostructured photonic materials. These materials can be engineered to enhance or suppress light reflection in certain wavelengths.
... we're very excited because this design makes viable both industrial-scale and off-grid applications."
The material is made of quartz and silicon carbide,...
The new device is capable of achieving a net cooling power in excess of 100 watts per square meter.
Radiative cooling has another profound advantage over all other cooling strategy such as air-conditioner. It is a passive technology. It requires no energy. It has no moving parts.
This sounds like key technology for surviving heat emergencies without power. But would these panels have to be removed before Winter to avoid cooling when you don't want it?