A device that can generate electricity while desalinating seawater has been developed by researchers in Saudi Arabia and China, who claim that their new system is highly efficient at performing both tasks. The device uses waste heat from the solar cell for desalination, thereby cooling the solar cell. It also produces no concentrated brine as waste, cutting its potential environmental impact.
In many parts of the world, climate change and population growth are putting huge demands on freshwater supplies. In some coastal regions, desalination – removing the salt from brackish water or seawater to turn it into fresh water – is increasingly being used to meet demand. Indeed, there are now around 16,000 desalination plants around the world producing about 95 million cubic metres of freshwater every day .
However, current desalination systems can be expensive and energy hungry, producing significant carbon emissions. The process can also produce highly concentrated salt water, or brine, as well as freshwater. This brine can also contain toxic chemicals introduced during the desalination process and if not disposed of properly, it can have negative environmental impacts.
Climate change is also driving demand for renewable energy, like solar power. Simultaneous electricity and freshwater production using the waste heat from solar cells for desalination has been touted as a way to cut the energy required for desalination. However, this has typically resulted in a trade-off between efficient electricity generation and efficient desalination.
Now, Wenbin Wang at King Abdullah University of Science and Technology in Saudi Arabia and colleagues claim to have developed a new device called a PV-membrane distillation-evaporative crystallizer (PME) that combines efficient desalination and electricity generation.
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