Electricity and water from a single device

The device, designed by Peng Wang and colleagues at King Abdullah University of Science and Technology, consists of a three-stage membrane distillation unit mounted on the back of a panel containing silicon solar cells. 

Unlike most solar cells that lose energy as waste heat, the new device utilizes this heat to evaporate water, which then condenses to produce clean water. 

The device is as much as nine times more efficient than existing solar desalination systems. It can help a conventional solar farm produce electricity and freshwater without using additional land, says Wang. 

It can produce clean water from various water sources such as seawater, brackish water, contaminated surface water and groundwater. The device doesn’t need frequent cleaning and salt removal, because it can concentrate salt and dirt present in the source water and wash them out into a wastewater chamber, making it suitable for long-term operation. 

The water produced can be used for removing dust particles from solar panels, crop irrigation, and drinking.

Although this technology is not a breakthrough, it is an interesting approach, says Mohammad Khaja Nazeeruddin of École Polytechnique Fédérale Lausanne in Switzerland, who was not involved in the research.  

Next, the researchers plan to devise ways to scale up the technique and find ways to reduce the cost.

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