Stanford University has demonstrated that heat from the sun and the chill of outer space can be collected simultaneously with a single device.

The project could lead to new devices for harvesting solar and space energy that do not compete for land space and can actually help each other function more efficiently.

Objects give off heat as infrared radiation - a form of light invisible to the human eye.

Most of this radiation is reflected back to Earth by particles in the atmosphere, but some of it escapes into space, allowing surfaces that emit enough radiation within the infrared range to drop below the temperature of their surroundings.

Radiative cooling technology reflects copious amounts of infrared light, providing an air conditioning alternative that does not emit greenhouse gases.

It may also help improve solar cell efficiency, which decreases the hotter solar cells become - if only the two technologies can coexist peacefully on one rooftop.

Stanford engineers have developed a device combining radiative cooling with solar absorption technology – using a germanium solar absorber on top of a radiative cooler with silicon nitride, silicon, and aluminium layers enclosed in a vacuum to minimise unwanted heat loss.

Both the solar absorber and the atmosphere are transparent in the mid-infrared range of 8-13 microns, offering a channel for infrared radiation from the radiative cooler to pass through to outer space.

The team demonstrated that the combined device can simultaneously provide 24℃ in solar heating and 29℃ in radiative cooling, with the solar absorber improving the radiative cooler's performance by blocking heat from the sun.

More information is accessible here.