A new solar panel can use waste heat to turn air into water
A new solar panel designed by scientists in Saudi Arabia can use waste energy to convert air into water. The research team suggests using the technology in arid regions to generate electricity and grow crops simultaneously. They believe that this technology will help address climate-related issues such as water shortages.
Solar panels often create excess heat that is not converted to usable energy. In the research team’s conceptual design, extra heat energy from the solar panels is used to draw water from the air, which it then uses to grow plants.
The device uses an atmospheric-water-harvesting (AWH) material, a hydrogel, to capture water vapor from the air during the cooler hours at night. The excess heat captured by the panel evaporates water from the hydrogel during the day. The water vapor is then collected and condensed so that the device can water the crops.
The research team tested their design for 3-months, growing water spinach outdoors in Saudi Arabia over the summer. The crop had a 95% survival rate, and no energy was consumed in the process. The panels had an electricity conversion efficiency of around 10% and, at their peak, generated ∼100 Wh per day.