About 450,000 residents in the Corpus Christi (Texas) metropolitan area are primarily served by fresh water from two severely threatened reservoirs, but the city has become increasingly reliant on water sent via the Mary Rhodes Pipeline from Lake Texana and the Colorado River. The city remains under stage 3 water restrictions despite recent heavy rains. Lake Corpus Christi is only a third full, while the rains raised Choke Canyon Reservoir’s water level to 20% full.
The city has twice voted to delay a final vote to approve the billion-dollar, privately funded, state and federally permitted desalination Inner Harbor desalination plant that when operational would produce 30 million gallons per day of potable water – about a quarter of the city’s water need (including that of its burgeoning industrial sector).
One possible reason for the second delay was the rains that have pushed back the predicted date for imposing a stage 1 water emergency till the end of 2027. Should that emergency kick in, the city would be only 180 days from not being able to meet water demand – and require residents to cut their water usage by 25%. Even if the council approves the Inner Harbor project at its September meeting, the plant will not become fully operational until sometime in 2029.
The Nueces River Authority has already partnered with the Israeli desalination firm IDE Technologies to build the plant – though its request for funding from the Texas Water Development Board was not granted. IDE uses a modular design that allows major plant components to be manufactured and assembled in phases to reduce construction timelines and fast-track the first-delivery date.
Corpus Christi still seems more willing than the state of California to approve desalination projects. While the Doheny Ocean Desalination plant made it through the permitting process and is scheduled to be operational by 2029, the much larger Huntington Beach Desalination plant was formally rejected by the California Coastal Commission after a 20-year fight and opposition by over 100 groups over projected water costs and fears of climate change causing flooding.
Doheny, when operational, will serve about 35,000 people, while the Huntington Beach plant was to supply about 450,000 people in an area severely damaged by recent fires. While Orange County residents may have been happy the plant was voted down, Corpus Christi Mayor Paulette Guajardo believes the city’s ongoing water crisis will be the number one issue in November.
Traditional desalination has involved reverse osmosis, in which salty water is pressed against a membrane hard enough that fresh water squeezes through and the salt stays behind. On land, this requires a bank of high-pressure pumps – and running those pumps runs up the cost of delivery.
To get around that problem, a Bay Area company called OceanWell has already pilot-tested a scheme that involves putting the membrane filters into a sealed pod and placing it 1,300 feet below the surface so that the weight of the water overhead eliminates the need for pumps, potentially cutting costs by up to 40%.
By drawing water in slowly, OceanWell is minimizing damage to sea life. During the trial, cameras showed fish swimming around the screens and a diving bird hunting a school of fish right next to the equipment. The internal prefilters and automated backwash enabled live algae, diatoms, and copepods to avoid being swept into the pod.
The demonstration was run in the Las Virgenes Reservoir at only 50 feet below the surface and reduced dissolved solids levels in the treated drinking water from 320 ppm to just 50 ppm. The 3-month trial also yielded more than 150,000 gallons of water at just 7% downtime, all for scheduled maintenance. Now OceanWell is ready to test the pods in Santa Monica Bay this fall.
Chinese scientists meanwhile have been developing a new solar-powered desalination technology that uses no electricity at all to produce fresh water – making it especially attractive in water-short areas that are also deficient in electric power generation. The Chinese believe this technology can cut the cost of producing fresh water from seawater to below that of bottled water and can become a low-cost, sustainable solution to water shortages.
The Chinese scientists, drawing inspiration from a shirt button, constructed nanoparticle spheres and threaded them together with polymer just as yarn is pulled through the holes in a button. The resulting structure, consisting of billions of microspheres, proved extremely robust and durable in conditions that simulated a squally coastline.
In an initial trial, the individual spheres reflected light out into each other, boosting the solar-thermal capacity to 90.2% and ensuring that the heat radiating out into the water was hot enough to drive evaporation up to 45.7%. This sunlight-only system produced 5.3 gallons of World Health Organization grade drinking water each day that was used to irrigate 54 square feet of farmland growing bok choi, beans, and corn throughout a full growth cycle.
The Chinese team has more work to do to improve condensation efficiency and reduce system costs but plans to scale up the technology for use in water-scarce coastal areas, islands, and remote regions.
Ocean mining to many involves giant scoops digging up seabeds. Controversies range from environmental concerns to geopolitical arguments over rights. But Texas-based SuperCritical Materials Corp. intends instead to mine uranium from seawater – and leave the seabed alone.
The company, which just won an exclusive license from the Department of Energy to extract uranium from seawater, intends to extract uranium from seawater with specially treated acrylic fibers to which dissolved uranium ions bind. While seawater contains an average of just 3.3 parts per billion uranium, SuperCritical’s goal is to capture that uranium, convert it into a gas, enrich it, and fabricate it into fuel for nuclear power plants.
Founder and CEO Alexander Canon Bryan says his long-term goal is to transform the U.S. from a net importer to a net exporter of uranium and nuclear fuels. The company hopes its first plant can produce 1.85 million pounds of uranium annually for at least 40 years – enough to power 4 million households throughout its productive life.
SuperCritical has already raised $4.5 million and has plans to go public later this year. But just to get permission to construct and operate, the firm has to work with 13 state and federal agencies, including the Texas Commission on Environmental Quality, the Texas Railroad Commission, and the U.S. Coast Guard.
While the firm says it can develop uranium as soon as 2030, it has yet to make a final investment decision to go ahead with the project. But imagine if SuperCritical could integrate uranium recovery with desalination in a manner similar to that proposed for the Diablo Canyon nuclear power plant in California.
This piece originally appeared at RealClearEnergy.org and has been republished here with permission.
