Renewables are on the rise, coal is bleeding out, and natural gas is frustratingly cheap. While the energy sector fights it out for the future of the planet, researchers around the world are sneakily coming up with proof-of-concept technologies that may provide our gizmos with new sources of power further down the line.
Enter left stage, MIT’s thermal resonator. This rather magical-sounding device doesn’t need anything other than the ambient environment to generate electricity, which it does so by “harvesting” lingering thermal energy. This isn’t witchcraft, dear readers: this is the bleeding edge of engineering, and although we wouldn’t expect to own one anytime soon, it’s hard to argue that this isn’t extremely clever stuff.
Have you heard of the thermoelectric effect? It’s a neat quirk of physics that allows for the generation of a voltage when a specialized device known as a thermocouple is registering at different temperatures on either side of it. At the same time, if you add a voltage to the thermocouple, it’ll result in a temperature difference across the device.
Thermoelectric devices that utilize this effect aren’t new. They’re used in diesel engines, and occasionally in watches – wasted thermal energy escaping from the system is recaptured and transformed into electricity, making systems more energy efficient.
The problem with said devices is that a temperature difference has to be maintained across the device at all times. In the absence of anything causing this – sunlight fluctuations, say – no electricity can be generated, and this, according to an MIT-authored Nature Communications paper, is where their new device comes in.
They’ve concocted the world's first thermal resonator, a device that they note can generate electricity based on small temperature fluctuations in the surrounding environment. As these happen everywhere, from the darkest shadows to the tops of mountains, this makes their device incredibly versatile.