Quantcast
ZME Science
  • CoronavirusNEW
  • News
  • Environment
    • Climate
    • Animals
    • Renewable Energy
    • Eco tips
    • Environmental Issues
    • Green Living
  • Health
    • Alternative Medicine
    • Anatomy
    • Diseases
    • Genetics
    • Mind & Brain
    • Nutrition
  • Future
  • Space
  • Feature
    • Feature Post
    • Art
    • Great Pics
    • Design
    • Fossil Friday
    • AstroPicture
    • GeoPicture
    • Did you know?
    • Offbeat
  • More
    • About
    • The Team
    • Advertise
    • Contribute
    • Our stance on climate change
    • Privacy Policy
    • Contact
No Result
View All Result
ZME Science

No Result
View All Result
ZME Science
No Result
View All Result
Home Science News

US and Chinese researchers develop cheap solar still to produce drinking water

Alexandru Micu by Alexandru Micu
February 18, 2020
in News, Physics, Science, World Problems

A team of researchers from the US and China has developed a passive, solar-powered desalinization system that could quench the thirst of remote, arid coastal areas on the cheap.

Image credits Zhenyuan Xu et al., (2020), Energy Environ. Sci.

The system employs several layers of solar evaporators and condensers stacked on top of each other in a vertical array, topped off with an insulating layer of (transparent) aerogel.

Salt-B-gone

“When you condense water, you release energy as heat,” says corresponding author Evelyn Wang, professor of mechanical engineering and head of the Department of Mechanical Engineering at MIT. “If you have more than one stage, you can take advantage of that heat.”

The system uses heat released by each layer to take salt out of seawater, eventually yielding drinkable water. Essentially, it’s a series of solar-powered liquor stills all working in tandem — the energy released by each layer (or ‘stage’) is captured by the next one and re-used. The team showed that their rig can achieve a very impressive 385% conversion rate of sunlight into energy used to evaporate water.

ADVERTISEMENT

The flat panels absorb heat from sunlight and transfer it to the water, making it evaporate. As the vapor rises, it encounters the next stage, where it condenses on the surface of a new panel. This also helps to transfer heat from the vapor to the receiving panel. Turning water vapor into liquid is as simple as cooling it down; in a traditional still, waste heat from the vapor is released into the environment. The team designed their multi-layered evaporator specifically to retain and reuse this energy, boosting its overall efficiency and speed.

In theory, extra layers can be added to make the system even more efficient at churning our drinkable water, but each layer means more cost and weight. They settled on a 10-stage evaporator as an acceptable compromise between cost and efficiency and installed it on an MIT building rooftop.

They report that the device yielded 5.78 liters per square meter of solar collecting area (1.52 gallons per 11 square feet) per hour, or about twice as much as any other passive solar-powered desalinization system, according to Wang. The still showed no signs of salt accumulation and didn’t produce any brines that needed to be disposed of, the team adds, meaning that the still can be set out in “a free-floating configuration” during the day

ADVERTISEMENT

The device is still at a proof-of-concept stage, and the team plans to further refine it — they plan to double its efficiency. It’s also built from inexpensive materials, such as a commercial black solar absorber and paper towels. The aerogen layer on top is the single most expensive component, but the team says less expensive insulators could be used as an alternative.

Get more science news like this...

Join the ZME newsletter for amazing science news, features, and exclusive scoops. More than 40,000 subscribers can't be wrong.

   

Ultimately, the team plans to scale-up their device and tailor it for commercial use. They hope the still — which they call a thermally localized multistage desalination system — will help provide drinking water for developing areas that lack reliable electricity but have ample seawater and sun.

The paper “Ultrahigh-efficiency desalination via a thermally-localized multistage solar still” has been published in the journal Energy & Environmental Science.

Tags: desalinizationsolarwater
Alexandru Micu

Alexandru Micu

Stunningly charming pun connoisseur, I have been fascinated by the world around me since I first laid eyes on it. Always curious, I'm just having a little fun with some very serious science.

Follow ZME on social media

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
  • Coronavirus
  • News
  • Environment
  • Health
  • Future
  • Space
  • Feature
  • More

© 2007-2019 ZME Science - Not exactly rocket science. All Rights Reserved.

No Result
View All Result
  • Coronavirus
  • News
  • Environment
    • Climate
    • Animals
    • Renewable Energy
    • Eco tips
    • Environmental Issues
    • Green Living
  • Health
    • Alternative Medicine
    • Anatomy
    • Diseases
    • Genetics
    • Mind & Brain
    • Nutrition
  • Future
  • Space
  • Feature
    • Feature Post
    • Art
    • Great Pics
    • Design
    • Fossil Friday
    • AstroPicture
    • GeoPicture
    • Did you know?
    • Offbeat
  • More
    • About
    • The Team
    • Advertise
    • Contribute
    • Our stance on climate change
    • Privacy Policy
    • Contact

© 2007-2019 ZME Science - Not exactly rocket science. All Rights Reserved.