Saturday, August 5, 2023

"Can We Desalinate Water Without All the Mess?"

Figuring this out would go a long way toward solving multiple problems and probably mint a billionaire-or-ten along the way.

From Hakai Magazine, July 5:

A new generation of small, modular, mobile, wave-powered devices is looking to tackle desalination’s biggest problems head-on.

In May 2022, California officials unanimously rejected a plan to build a US $1.4-billion desalination plant in Huntington Beach. The plant, the officials said, would produce costly water and possibly harm the marine environment. The decision wasn’t an outright rejection of desalination, but it did highlight some of the problems that have made desalination an impractical solution to California’s water problems.

Dragan Tutic, founder and CEO of Oneka Technologies, says large desalination plants powered by fossil fuels aren’t the only way to get fresh water out of the ocean. His company is getting ready to bring what it says is sustainable, practical desalination to the small city of Fort Bragg on California’s North Coast.

Fort Bragg was a lumber town until the Georgia-Pacific mill closed in 2002. Today, it’s a popular tourist spot featuring undomesticated beaches wrapped in rocky cliffs, lively tide pools, and a beach famous for sea glass.

As in much of California, water is a precious commodity in Fort Bragg. The city has only three surface water sources: the Noyo River and two small tributaries. In dry years, all three can slow, and the Noyo can turn brackish, putting the city at risk from shortages.

“We’re kind of stuck,” says John Smith, Fort Bragg’s director of public works. “That’s why we’re looking to the ocean.”

Desalination is an idea that keeps reappearing in the Golden State, where overdrawn groundwater and shrinking reservoirs are critical problems. On a superficial level, it seems simple: take the salt out of the abundant salt water just offshore. But typical desalination facilities are big, expensive to operate, and environmentally unfriendly, especially when the resource-intensive process is powered by fossil fuels. The Carlsbad desalination plant in Southern California, for example, sits on 2.4 hectares of land and uses 246,156 megawatt hours of electricity per year—equivalent to the usage of roughly 23,000 homes....


This November '22 post mentions one of the most intractable problwms:

Desalination: California Is Waking Up To Reality
It's about time.
If California doesn't realize they don't own the Colorado River the other states and the federal government will remind them....

.... And then there is the brine — the salty, sludgy byproduct of desalination that typically gets released back into the ocean at the end of the process. A global survey of desalination in 2019 found that plants produce about 5 billion cubic feet of salty brine every day — 50% more than previous estimates. High concentrations of brine can reduce oxygen and increase toxicity in marine environments. That’s caused some to worry about what what decades — or even centuries — of desalination could do to the ocean...

A point made just yesterday via MENA FN:

Renewables Integration, Brine Management Vital To Sustainable Desalination

....According to a 2019 United Nations-backed paper, 55% of global brine is produced in just four countries: Saudi Arabia (22%), UAE (20.2%), Kuwait (6.6%) and Qatar (5.8%). Middle Eastern plants primarily operate using seawater and thermal desalination technologies...