Are Infrared Emissions an Untapped Energy Source?

March 7, 2014

It is possible to harvest energy from Earth's thermal infrared emissions into outer space, according to new research from the Harvard School of Engineering and Applied Sciences (SEAS).

Heated by the sun, our planet is warm compared to the frigid space beyond. Thanks to recent technological advances, the researchers say that heat imbalance could soon be transformed into direct-current (DC) power, which would take advantage of a vast and untapped renewable energy source.

"The mid-IR has been, by and large, a neglected part of the spectrum," says principal investigator Federico Capasso, a senior research fellow at Harvard SEAS. "Even for spectroscopy, until the quantum cascade laser came about, the mid-IR was considered a very difficult area to work with. People simply had blinders on."

Now, Capasso and his research team are proposing something akin to a photovoltaic solar panel, but instead of capturing incoming visible light, the device could generate electric power by releasing infrared light.

To read the full report, visit the Proceedings of the National Academy of Sciences.