Free the Ocean Blog

Turning seawater to sipping water with the sun!

Water enthusiasts and eco-advocates, here’s some good news that might pique your interest. Thanks to a collaborative effort between the US and China, we’re on the brink of tapping into our oceans for drinkable water with a passive solar-powered desalination device. This innovative prototype is capable of producing an impressive 4-6 liters of fresh water per hour. And if the initial results are any indication, a scaled-up model could adequately serve coastal households throughout sunny regions year-round.

Essential water facts:

  • Freshwater availability on Earth? A scarce 3%
  • The Earth’s vast undrinkable, saline bounty? A massive 97%

Given these stats, researchers from MIT and Shanghai Jiao Tong University engineered a compact desalination device, roughly the size of a briefcase. It ingeniously leverages the “thermohaline” circulation phenomenon — a natural process where the oceans essentially regulate their salinity and temperature. If you’re intrigued by the term “thermohaline,” think of it as the “Great Ocean Conveyor Belt.” It’s a colossal, albeit slow-moving current, primarily driven by the denser, salt-rich water from the polar regions moving and subsequently making way for fresher water. It’s such a significant process that even NASA has extensively studied it!

Photo Credit: Jintong Gao and Zhenyuan Xu

Solar Desalination: Bridging Innovation & Sustainability

Mimicking the ocean’s natural process, the device allows seawater to form eddies. With the assistance of sunlight, the water evaporates. This leaves the salt content behind and gives us potable water. And here’s where it gets even more interesting: According to Lenan Zhang from MIT’s Device Research Lab, this solar-desalinated water might be more cost-effective than conventional tap water!

For coastal communities grappling with water scarcity, this innovation isn’t just groundbreaking; it’s potentially life-changing. Moreover, with a design lifespan of 10 years, it promises durability and consistent performance.

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