May 8, 2024

Sustainable Electricity-Free Air Conditioner Can Harness Solar Energy To Reduce Temperatures on Hot Days

KAUST scientists have actually developed a basic cooling system based on solar power and the cooling impact of saltwater evaporation that might be utilized for refrigeration in hot areas with restricted access to electricity. Credit: © 2021 KAUST; Veronica Moraru
Strong Sunlight Powers Passive Cooling Device
An easy cooling system driven by the capture of passive solar energy could offer inexpensive food refrigeration and living area cooling for impoverished communities with no access to the electrical energy grid. The system, which has no electrical parts, makes use of the effective cooling impact that takes place when certain salts are dissolved in water. After each cooling cycle, the system utilizes solar power to evaporate the water and regenerate the salt, prepared for reuse.
” Hot areas have high levels of solar energy, so it would be extremely attractive to use that solar power for cooling,” says Wenbin Wang, a postdoc in Peng Wangs lab. In lots of parts of the world, there is a greater need for cooling since of climate modification, however not every community can access electrical energy for cooling and refrigeration. “We conceived an off-grid solar-energy conversion and storage design for low-cost and green cooling,” Professor Wang says.
The cooling system developed by KAUST engineers could be used to cool spaces in homes. Credit: © 2021 KAUST; Wenbin Wang
The team created a two-step cooling and regeneration system, with the cooling step based upon the reality that liquifying specific typical salts in water takes in energy, which rapidly cools the water. After comparing a series of salts, ammonium nitrate (NH4NO3) proved to be the standout entertainer, with a cooling power more than four times greater than its closest rival, ammonium chloride (NH4Cl). The ammonium nitrate salts extraordinary cooling power can be associated to its high solubility. “NH4NO3s solubility reached 208 grams per 100 grams of water, whereas the other salts were normally listed below 100 grams,” Wenbin states. “This salts other benefit is that it is really cheap and already commonly used as fertilizer,” he adds.

A simple cooling system driven by the capture of passive solar energy could offer low-cost food refrigeration and living space cooling for impoverished neighborhoods with no access to the electrical energy grid. The system, which has no electrical components, exploits the powerful cooling result that occurs when particular salts are dissolved in water.” Hot regions have high levels of solar energy, so it would be really appealing to utilize that solar energy for cooling,” says Wenbin Wang, a postdoc in Peng Wangs lab. The group developed a two-step cooling and regrowth system, with the cooling action based upon the reality that liquifying particular common salts in water soaks up energy, which quickly cools the water.

The system has good potential for food storage applications, the group revealed. When the salt was gradually dissolved in water in a metal cup put inside a polystyrene foam box, the temperature level of the cup fell from room temperature level to around 3.6 degrees Celsius and remained listed below 15 degrees Celsius for over 15 hours.
As soon as the salt service reached space temperature level the group utilized solar energy to vaporize the water using a bespoke cup-shaped 3D solar regenerator. “The taken shape salt can be collected automatically as the salt drops off due to gravity,” Wenbin says.
As soon as gathered, the salt efficiently represents a stored kind of solar power, ready to be reused for cooling again when required.
Recommendation:” Conversion and storage of solar power for cooling” by Wenbin Wang, Yusuf Shi, Chenlin Zhang, Renyuan Li, Mengchun Wu, Sifei Zhuo Sara Aleida and Peng Wang, 1 September 2021, Energy & & Environmental Science.DOI: 10.1039/ D1EE01688A.