Researchers Use Radiative Cooling Strategy to Harvest Solar Energy

The new strategy could surpass the electricity savings of a bare solar cell by 30%

March 18, 2024


Researchers at Pennsylvania State University (PSU) have developed a dual cooling and power generation strategy that simultaneously harvests solar energy in a solar cell and directs heat away from the Earth through radiative cooling.

As conventional energy generation methods come with increased environmental costs, the researchers took to turning two underutilized renewable resources, the sun and outer space, into solutions to generate electricity and passively cool down structures.

In a recently published study in the Cell Reports Physical Science journal, the team mentioned that radiative cooling works by sending infrared light directly into outer space instantaneously without warming the surrounding air.

“In radiative cooling, the infrared light radiates from a piece of transparent, low-iron glass. The light bounces off the glass, passes through the atmosphere without warming the surrounding air, and lands in outer space, which we call the cold universe,” said Linxiao Zhu, team lead and assistant professor of mechanical engineering at PSU.

This process, Zhu explained, further cools the surface of the radiative cooler. Underneath the radiative cooler, the researchers positioned a solar panel, which, during daylight hours, ensured that sunlight passed through the transparent cooler and was absorbed into the solar cell to generate electricity.

Last year, the team also found that the combined benefit of electricity generation and cooling from the dual harvesting system could surpass the electricity saving of a bare solar cell by as much as 30%. The research found that harvesting the combined efficiency of the two resources yields a higher performance than using either of them alone. This further allowed them to significantly outperform a bare solar cell, a critical renewable energy technology.

“At the same time and in the same place, we can exploit these renewable resources together, 24 hours a day,” said Pramit Ghosh, a doctoral student at Penn State

Further, the researchers claim that since the two harvesters are stacked atop each other, they take up minimal space on a rooftop or the ground.

Two years ago, researchers at Stanford University developed a solar cell that used radiative cooling to avoid the need for batteries by harvesting energy during the day and night.

Last February, another set of Penn State researchers also created a process to create next-generation solar cells where large perovskites were fabricated faster with less waste.