Scientists turn seawater into fresh water without harmful brine

Science Daily ^ | September 16, 2026

[TheDon]

Summary: Scientists have developed a solar-powered desalination system that turns seawater into fresh water while removing nearly all of the leftover salt as a solid instead of producing harmful brine. The self-cleaning technology could also recover valuable minerals such as lithium, potentially turning desalination waste into a useful resource.

...

Scientists at URochester's Institute of Optics created a solar thermal desalination system designed to produce fresh water efficiently without generating liquid brine or requiring chemical additives to pre-treat the incoming water.

The research was led by Chunlei Guo, a professor of optics and physics ...

At the heart of the technology are solar panels made from black metal that has been treated with femtosecond lasers. A femtosecond is an extraordinarily short unit of time, equal to one quadrillionth of a second. Pulses from these ultrafast lasers can precisely alter a material's surface, creating microscopic structures that dramatically change how it interacts with light and water.

The laser treatment makes the metal extremely effective at absorbing sunlight and also gives it superwicking properties, meaning water spreads rapidly across the surface instead of beading up.

Each panel contains a laser-treated active region that draws a very thin layer of seawater across its surface. The dark metal absorbs nearly all of the incoming solar radiation, heating the water and causing it to evaporate.

That evaporation leaves salts and other dissolved minerals behind. Rather than allowing those materials to accumulate where evaporation is taking place, the panel directs them toward untreated areas along its sides, known as the passive region.

This movement is important because salt buildup is one of the biggest challenges facing solar desalination systems. If minerals form a hard layer across the active surface, they can block water movement and eventually stop the system from working.

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TOPICS: News/Current Events
KEYWORDS: desalinization; femtosecond; laser; solar

[TheDon]

Clever new desalination technology.

[ClearCase_guy]

Put AI data centers on floating platforms in the ocean. All the water they need, plus solar power.

[E. Pluribus Unum]

Thar's gold in thet thar seawater: https://x.com/i/grok/share/4417fdd943ca4e91b88eed55fd78c511

[pissant]

Likely as clever as the University of Utah guys’ cold fusion

[Silentgypsy]

Vulnerability?

[Red Badger]

Gold, silver, platinum, copper, fish poop...............Jimmy Hoffa...................

[dennisw]

“The newer Sorek B plant has a contracted price around $0.41/m³, which works out to only $0.00155/gallon — about 0.16¢ per gallon.”

Israeli desalinated water is 0.16¢ per gallon. The experimental method here with lasers is prolly 30x as expensive. So can it scale up to be a lot less expensive?

[Silentgypsy]

The article didn’t address feasibility in terms of cost.

[Quality_Not_Quantity]

Likely as clever as the University of Utah guys’ cold fusion

Is that the one that's been 10 years away from viability for - what it is now? - going on 30+ years?

[Attention Surplus Disorder]

“Israeli desalinated water is 0.16¢ per gallon. The experimental method here with lasers is prolly 30x as expensive. So can it scale up to be a lot less expensive?”

I suspect, but do not know, that Israeli (and other existing) methods include the amortized costs of dealing with the brine. Which is a big honking pipe under the sea and the associated pumps. The costs are not horrific, but they are not nothing.

[SaveFerris]

They’ll have all the salt 🧂 they’ll ever need!

[poinq]

Israel and other countries have been doing this for a while. Solar panels are perfect because they can work separating the water when the sun shines and turn off when it doesn’t. There is no hurry, the water can wait. As far as the brine is concerned, its just a matter of separating all the water or letting some go back in the sea. There are lots of things in the sea besides salt. But they come in very small amounts.

[TheDon]

I believe the lasers are only used in the production of the ‘black metal’. The material then performs the separation of water and other materials. It sounds like a very promising technology.

[muir_redwoods]

Theres about 100 pounds of gold in a cubic mile of seawater. The tricky bit is processing a cubic mile of water economically

[catnipman]

nothing in the article about:

1. amount of fresh water per hour per square meter of miracle laser-etched superwicking black metal

2. cost of production of a square meter of miracle laser-etched superwicking black metal

3. longevity of miracle laser-etched superwicking black metal

for example, would it take square miles of this stuff to make a reasonable amount of water, costing billions of dollars and lasting only a year before wearing out or whatever?

[Bob434]

PHEW!!!! JUST in time... considering that the sea is rising like 100 feet every month!

[Some Fat Guy in L.A.]

while removing nearly all of the leftover salt as a solid instead of producing harmful brine

Isn't 75% of the earth covered with "harmful brine"? What's the problem with it?

[Eastern Shore Virginian]

Ha! I knew femtosecond was the key! I could have done that myself but I keep forgetting what drawer I keep that femtosecond in. (It kept getting tanged in my string theory so I had to put it away).