While researchers and scientists look at innovative ways to make solar panels more efficient and cost-competitive, others have come up with a solar technology with a bonus—free drinking water.
Researchers at the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia have developed a device that not only produces electricity, but also provides clean drinking water using only renewable energy for both processes.
Deriving both drinking water and energy from the sun could be a major breakthrough not only in solar technology but also in helping a large portion of the world’s population to get access to safe clean water, especially in arid and poor areas in Africa.
The device that the scientists at the Saudi Arabian university developed is still a small proof-of-concept early-stage technology, but researchers hope they can replicate it in a larger size and potentially on a large scale in the future.
Scientists at the University’s Water Desalination and Reuse Center led by Professor Wenbin Wang have developed a multifunctional device that is attached to the backside of the photovoltaic (PV) panel.
Typically, a solar panel turns sunlight into electricity at an efficiency rate of just 20 percent, meaning that the remaining 80 percent of heat is just wasted, mostly in the form of heat in the air.
The scientists have constructed a device with water channels and membranes that uses the heat from the panel to vaporize seawater from one container and condense it into clean fresh water that is collected in another container.
The electricity output at the PV panel is not affected by the water desalination process taking place beneath it, they say.
According to the team of researchers who published the findings of their study in the journal Nature Communications, the device could in the future turn an electricity-producing power plant from a water consumer into a fresh water producer. Moreover, combining solar electricity production with clean water production at one site could slash capital costs for solar and desalination plants because with the device, electricity and desalinated water production would share the land and the system, the scientists say.
“The water-energy nexus is one of the main issues threatening sustainable global development,” Wenbin said in a press release.
The scientific team now plan to expand their research and device development by incorporating agricultural production into the system.
“Raising sheep in the field of PV farms is feasible because grass grows well using the fresh water from solar-panel washing,” Wenbin said in the university’s statement. “A PV farm with sheep grazing while seawater is being desalinated using our device could be ideal in arid regions near the coast.”
Speaking to Forbes contributor Scott Snowden, Wenbin said:
“It’s our hope that we quickly move to push this technology towards large-scale adoption and use.”
If the device proves to be applicable at a larger commercial scale, it could not only contribute to renewable energy production, but it could potentially reduce water usage at solar power plants, and help at least part of the millions of people around the world who don’t have access to clean drinking water. According to estimates from the World Health Organization (WHO), 71 percent of the global population, or 5.3 billion people, used a safely managed drinking-water service in 2017. The other 2.2 billion people without safely managed services included 1.4 billion people with basic services, meaning an improved water source located within a round trip of 30 minutes. Another 206 million people had a water source requiring more than 30 minutes to collect water, 435 million people were taking water from unprotected wells and springs, and 144 million people were collecting untreated surface water from lakes, ponds, rivers, and streams.
If the solar electricity, clean water producing device could be replicated on a large scale, it could increase clean energy production, reduce water waste, and produce drinking water at the same time.