Scientists Discover Way to Harness Solar Power at Night

Scientists may have figured out a way to harness solar power even at night, according to a study published in the journal Nature Chemistry.

Researchers from MIT and Harvard teamed up to develop new photoswitches that can harness the power of the Sun and release its energy day or night.

"Some molecules, known as photoswitches, can assume either of two different shapes, as if they had a hinge in the middle," MIT researchers said in a press release. "Exposing them to sunlight causes them to absorb energy and jump from one configuration to the other, which is then stable for long periods of time."

And the best part is, while these molecules can efficiently produce "solar thermal fuel," they don't produce harmful greenhouse gases.

"It could change the game," said co-author Jeffrey Grossman, an associate professor of materials science and engineering.

The ability of these photoswitches to channel both light and heat into energy opens a world of possibilities. Grossman notes that "there are many applications where heat, not electricity, might be the desired outcome of solar power." And unlike fossil fuels that are burned and then consumed, this energy can be continuously recycled.

The revelation is a follow-up to research Grossman and his colleagues conducted three years ago. Past studies showed that the difference in heat between the two arrangements was miniscule, but the challenge was to create a design that yielded maximum energy output. They ended up attaching photoswitching molecules called azobenzene to a template of carbon nanotubes to achieve the desired effect.

"This result provides additional motivation for researchers to design more and better photochromic compounds and composite materials that optimize the storage of solar energy in chemical bonds," said Yosuke Kanai, an assistant professor of chemistry at the University of North Carolina who was not involved in this study.

He added that the findings are both "surprising and remarkable."