Smart windows could provide a green alternative to Wi-Fi

Researchers are developing a smart glass system that uses sunlight, rather than radio waves or light-emitting sources, to send data

Spotted: The carbon footprint of the internet and associated systems accounts for around 3.7 per cent of global greenhouse gas emissions, similar to the amount produced by the global airline industry. However, a group of researchers at the King Abdullah University of Science and Technology (KAUST) may have found a way to reduce this by harnessing sunshine for wireless data transmission.

The researchers have designed a smart glass system that can encode data into the light that passes through it. This can offer a greener mode of communication compared to conventional Wi-Fi or cellular data transmission.

The team’s system involved two parts – a light modulator that can be embedded in a glass surface, and an in-room receiver. The modulator consists of an array of smart glass elements known as Dual-cell Liquid Crystal Shutters (DLSs). The liquid crystal shutter array would act as a filter to encode signals into the light as it passes, and would require just one watt of power to operate – small enough to be supplied by a miniature solar panel.

Previous systems encoded data by varying the light intensity, but this can result in an uncomfortable flickering effect if the frequency of these intensity changes is low enough to be detected by the human eye. Instead, the new system works by changing the polarisation of the incoming sunlight at the modulator. The receiver detects this change and uses it to decode the transmitted data.

According to the team’s calculations, the proposed setup could transmit data at a rate of 16 Kilobits per second. This is too slow to be useful, but lead researcher Basem Shihada says that, “We are now ordering the necessary hardware for a testbed prototype implementation. We would like to increase the data rates from Kilobits to Mega and Gigabits per second.” If successful, future data exchange could be powered entirely by the sun.

There is new-found concern over the amount of energy being used by the internet and the associated infrastructure. To reach net zero, it will be necessary to make the information ecosystem much more energy efficient. Springwise has also spotted the harvesting of unused Wi-Fi to power electronics and using solar power to provide Wi-Fi.

Written By: Lisa Magloff