The technology that keeps smartphones working is going liquid-cooled.
It may come as a surprise to find out that these pocket-sized devices that can take photos, browse the internet and make calls are dependent on networks of "base stations."
These base stations use antennas to send and receive radio waves. This is important because, without the flow of radio waves, mobile communications wouldn't work.
Fan systems are usually used to keep base stations cool, but in Finland technology business Nokia has developed a station that is cooled using liquid instead.
"Traditionally, base stations have been cooled by air," Nokia Networks' Harry Kuosa told CNBC's Sustainable Energy. "This Nokia innovation is now using liquid as a coolant," Kuosa added, explaining that liquids were more effective than air at transferring heat from a base station.
This, Kuosa explained, meant that cooling systems such as air conditioning and fan units were not required, cutting energy consumption by about 30 percent and carbon dioxide emissions by 80 percent.
In December 2018 Nokia announced that, together with businesses Elisa and Efore, it had "commercially deployed a liquid-cooled base station" in a Helsinki apartment building.
Nokia said that heat from the base station had been redirected in order to heat the building, helping to cut energy costs in the process.
Looking at the bigger picture, connected and smart devices could have a big role to play in the future of energy efficiency.
"I think the first thing that we're going to see is virtual reality glasses," Steve Evans, director of research in industrial sustainability at the University of Cambridge's Institute of Manufacturing, told CNBC.
"Instead of your children using them to play games… we're going to be able to look in our factories and see energy flowing everywhere," he added. "We'll know if that energy is being used to add value… and if that energy is not adding value, we have to do something about it."