Skip to comments.An Unconventional Desalination Technology Could Solve California's Water Shortage
Posted on 03/12/2014 8:25:27 PM PDT by ckilmer
This year, farmers in California's Central Valley likely won't receive any water through the federal irrigation program, a network of reservoirs, rivers, and canals that is normally replenished yearly by ice melt from the Sierra mountains.
Crippling water shortages have made desalination technology more attractive, including a startup, WaterFX, that uses the sun to produce heat. The heat separates salt and water through evaporation.
WaterFX has fewer environmental repercussions than traditional methods of desalination that rely on fossil fuels to generate electricity.
The technology could not have come at a better time.
No end in sight
During a drought-free year, the federally run Central Valley Project provides enough water to irrigate 3 million acres of agricultural land. Last year, farmers only received 20% of their allotment.
The lack of water is not just worrying for growers. It affects all people who eat food. One third of the nation's produce is grown in the Central Valley — composed of Sacramento Valley in the north and San Joaquin Valley in the south — and the deep water cuts mean that more than half a million acres of crop land will be left unplanted.
Some scientists predict California's drought could last as long as a century . Going forward, the state is going to need a substantial water supply that doesn't rely on the aqueduct system, says Aaron Mandell, WaterFX chairman and founder.
However, in order to counter California's drought, the push must be toward renewable desalination plants rather than fossil-fuel dependent facilities that further contribute to climate change.
Making freshwater from sunshine
In WaterFX's system, a solar trough, which looks like a jumbo-sized curved mirror, collects energy from the sun's rays and transfers that heat to a pipe filled with mineral oil. The mineral oil feeds the heat into a system that evaporates the salty water being treated. Steam is produced, which condenses into pure liquid water. The remaining salt solidifies and can be removed, says Mandell. That salts can be used in other industries as building materials, metals, or fertilizers.
In order to operate continuously, the solar trough is very large so that it collects extra heat during the day. The energy is stored and used to run the system at night when the sun isn't shining.
By using sun as the fuel source, WaterFX uses roughly one-fifth of the electricity consumed by traditional desalination plants, according to Mandell. Less electricity means lower operating costs. With conventional desalination, electricity makes up 50-60% of the water costs, says Mandell. A typical desalination plant in San Diego operates at about $900 per acre-foot, while it costs around $450 to produce an acre-foot of water with WaterFX. (An acre-foot is 325,000 gallons, or the amount of water it takes to cover an acre at a depth of one foot).
"Solar desalination is still a very immature technology so there's a quite a bit of room to drive that cost down even further," said Mandell.
Many desalination facilities, including the $1 billion Carlsbad plant set to open in 2016, use a process known as reverse osmosis that forces seawater through billions of tiny holes that filter out salt and other impurities. This method can produce fresh water on a large scale, but has economic and environmental drawbacks. It uses an immense amount of electricity and only about half of the seawater that goes into the system comes out as clean water. The remaining half is dumped back into the ocean as salty brine where it can be harmful to marine plants and animals.
By contrast, Mandell says that WaterFX has a 93% recovery rate, meaning that for every 100 gallons of water that goes in, 93 gallons of usable water are spit out.
WaterFX also helps solve an issue that has long plagued irrigated land. Soils in the arid west of San Joaquin Valley naturally contain a lot of salt as well as high concentrations of metals, like selenium, which can be toxic to humans and wildlife. When the soil is irrigated, the salt, selenium, and other elements become concentrated in the drainage water that collects in a system of drains and pumps under the crops. In the past, harmful drainage water might have been discharged into rivers, wetlands, and aquifers in the San Joaquin Valley. Now, that otherwise unusable water can be diverted to WaterFX and turned into irrigation water again.
The first test
The Panoche Water District in Central Valley is home to the first demonstration plant, a 6,500-square foot system that is capable of producing around 10 gallons of freshwater a minute, or roughly 14,000 of freshwater each day.
When the demonstration plant is operating in commercial mode, running 24 hours a day, it can put out 25 to 30 gallons of freshwater a minute, says Mandell.
The pilot project, funded by the California Department of Water Resources, will hopefully prove that the WaterFX system is more reliable (it doesn't depend on the Sierra snowpack) and affordable than other freshwater sources.
The water that's being treated by the pilot plant streams in from a canal that collects salty drainage water from around 200 farms in the area and brings it to a single location. In the pilot phase, the clean water that's produced is blended back in with the drainage water, but a commercial plant would send the water back to farmers through a series of canals that are already in place.
Additionally, small-scale systems could be used by individual farmers on site to recycle their own drainage water.
A bright future
WaterFX is not the first company to experiment with solar desalination. The Sahara Forest project in Qatar and an Australian company called Sundrop Farms are using the technology to grow food in greenhouses. But this is the first time a company has focused on using the sun's energy "to produce a scalable, long-term water supply," Mandell said.
The goal is to eventually be able to treat salty groundwater in addition to drainage water.
The immediate next step for WaterFX is to expand operations in Panoche to produce 2 million gallons of water per day. "From there it's about laying out a pathway for replicating this model all up and down the Central Valley," Mandell said. "We're trying to put a plan in place so that by 2020, we may be in a position to wean ourselves off the aqueduct system entirely."
$450@acre foot is world class if they can do it in scale.
Sounds promising, but ... tagline.
Benjamin Reuter writes for the German magazine Wirtschafts Woche on Sundrop Farms’ participation in Qatar’s mission to become self-sufficient in food production. Full Article
Miracle in the Desert: Jonathan Margolis, an author and regular Observer contributor, travels to the Australian desert to discover an industrial Garden of Eden. Full Article
Of possible interest to you.
California has no choice but to follow Israel’s path in desalination. With almost 40 million people, there isn’t enough fresh water to go around. The only place where there is a limitless supply of potential fresh water is the Pacific Ocean.
As desalination technologies improve and the cost goes down, pumping water from the sea will become increasingly attractive in addressing water shortages caused by drought and surging human, agricultural and industrial needs.
The time when we are dependent on the sea has finally come calling.
The lack of water is not just worrying for growers. It affects all people who eat food.
***Yes it does. But there is this contingent of anti-science Luddites who refuse to examine the scientifically established alternatives, such as LENR for cheap desalination.
Just look at even the latest thread. Where do such skeptopaths even begin to look at the science behind the claims?
Don’t forget, Kalifornia is a Communist state. Once the capital is invested and the infrastructure in place, the state will confiscate it “in the interest of the people.”
“The lack of water is not just worrying for growers. It affects all people who eat food.”
Why... that’s almost all of ‘em.
When the demonstration plant is operating in commercial mode, running 24 hours a day, it can put out 25 to 30 gallons of freshwater a minute, says Mandell
Now, this is a SOLAR plant, right?
Is it possible it incorporates some sort of thermal storage so that it will keep going at night?
Yes, almost all of them.
A few are breatharians, for a few months anyway.
That’s exactly it. The pipes are filled with salt that heats up during the day and cools at night.
such as LENR for cheap desalination
LENR if/when it scales will collapse the cost of desalination.
My favorite energy cost killer is lftr thorium reactors. These have actually had demonstration plants in operation. (40 years ago) If/when they scale up, they’ll pull the cost of electricity down to 1/4-1/10 current cheapest cost coal/natural gas plant electrical generator.
LENR looks to make energy costs even cheaper. Which is great if it happens.
Another form of LENR that looks interesting to me is Dense Plasma Focus. http://bit.ly/1fsf7qb
There’s a couple variants of that.
It does look like there’s more interest/excitement in the LENR world. It stands to reason therefor — that articles from more mainstream publications in the next year or so will do pieces on LENR—as has happened with LFTR thorium reactors in the last two years.
LENR tests are not expensive. The work at MIT look pretty impressive. So it stands to reason there ought to be more big science university/government/corporate labs coming out with corroborating tests in the next year. There should be more scientists popping up with positive results. All you have to do is report them telling everyone ...just the facts mam.
In the end the keys to a successful 21st century are cheap water and cheap energy. It doesn’t really matter just how its done. Just that it gets done.
I considered becoming a Breatharian for the monetary savings and issues like this thread topic, but I decided to go with something longer term, even though it will be more expensive.
I’d do something ambitious and radical. Buy up all the land inside the Salton Sea Basin (up to Sea Level) then with Treaty with Mexico, create a large Canal (large enough for cargo and ocean lining ships, along with fishing ships) to go through to the Gulf.
It would serve both as an inland port, an endless supply of water through desalinization + would provide many miles of coastline for tourism, and wildlife coastal refuge.
-J.S. (Of course likely this would never happen especially in CA, but it would give all parties a worth-while resource).
In the end the keys to a successful 21st century are cheap water and cheap energy.
***That is my view as well. If it is by way of LFTR, then great. But when I look at the 2 technologies, I vastly favor LENR.
“Now, this is a SOLAR plant, right? “
If that’s really true, why is there a Natural Gas regulator and gas train attached to the equipment?
LENR? You mean Cold Fusion? Yeah, it's all the fault of luddites. You'd think if it were a real technology people would have done it by now. If you can do it, do it.
I vastly favor LENR.
The promise of LENR is the greater of the two. The reality of LFTR is the greater of the two.
We’ll see. Tables could be turned this year or not.