As part of a project developed by San Francisco area start-up WaterFX, a giant solar receiver in Firebaugh, CA, rotates to track the sun and capture its energy. The 377-foot array, however, does not generate electricity, but instead creates heat used to desalinate water. The goal is to tap the abundant, if contaminated, resource in this parched region: the billions of gallons of water that lie just below the surface.
The water is tainted with toxic levels of salt, selenium and other heavy metals that wash down from the nearby Panoche foothills, and is so polluted that it must be constantly drained to keep it from poisoning crops. This, coupled with the record-breaking drought that California is facing means that irrigation costs are going to double or triple as farms are forced to buy water on the spot market.
"Food prices are going to go up, absolutely", said Dennis Falaschi, manager of the Panoche Water District. "This year, farmers in the Panoche district will receive no water. Last year, they received only 20 percent of their allocation", Mr. Falaschi said. In 2012, the allocation was 40 percent. Farmers elsewhere who rely on the State Water Project to irrigate 750,000 acres of farmland will also receive no water in 2014.
Related Stories
So, as I write this, day one has officially come to an end. I'm still somewhat in shock over it. Last night when I was editing the database to change over hostnames and such, I was thinking, man, it would be great if we got 100 regular users by tomorrow. Turns out I was wrong. By a factor of ten. Holy cow, people. I'm still in a state of disbelief, partially due to the epic turnout, but also because our very modest server hardware hasn't soiled itself from the influx (the numbers are, well, "impressive" is a way to put it). Anyway, I wanted to do a bit of a writeup of where we stand now, what works, and what doesn't. Check it out (and some raw numbers) after the break! Warning, it is a bit lengthy.
(Score: 2, Insightful) by ArhcAngel on Monday February 17 2014, @03:10PM
If you are generating heat to desalinate the water presumably by turning it into steam to separate it from the salt why couldn't you also generate electricity by having the steam turn a turbine?
(Score: 5, Informative) by dx3bydt3 on Monday February 17 2014, @03:36PM
Doing both would be possible, but not as effective for producing the maximum quantity of clean water. All the energy extracted by the turbine could have been devoted to converting more water to steam. In order to get energy out of a turbine you have to add that much energy to superheat the steam, if that energy was instead devoted to making more steam, you'd get more clean water in the end.
(Score: 3, Informative) by Anonymous Coward on Monday February 17 2014, @03:59PM
To generate electricity from a gas turbine, the water needs to be heated to well above the boiling point, otherwise water will condense on the blades of the turbines and cause huge corrosion problems. In any situation where you have water that is already very hot, you can install some additional equipment to heat it enough for use in a steam turbine, but the additional expense is not always worthwhile.
(Score: 3, Interesting) by sl4shd0rk on Monday February 17 2014, @04:02PM
Seems to be working for these guys*. "The boilers superheat steam to temperatures of up to 550° C (over 1,000° F), which drives standard turbines to generate electricity."
* - http://www.gizmag.com/ivanpah-fully-operational/30 862/ [gizmag.com]
(Score: 3, Interesting) by VLM on Monday February 17 2014, @04:46PM
The problem is their future plant is only generating about a million bucks in water revenue per year, its really a very small plant, and high pressure boilers and turbines don't scale well to small size. So maybe 2 or 4 generations in the future, maybe if they successfully expand by a factor of ten each generation of plant...
In the long run it is probably a good idea for a future much larger plant.
(Score: 3, Informative) by dr zim on Monday February 17 2014, @04:57PM
The amount of heat produced is finite. Heat is removed from the water when it turns a turbine or when it is distilled. The water would be too cold to run either process efficiently if you tried to run both with the same water without another trip through a heater in between.
(Score: 1) by ArhcAngel on Monday February 17 2014, @05:51PM
Steam rises. If the reservoir of the resultant clean water is higher than the turbine there is no need for the heated water (steam) to be the power source but the force of gravity. The reservoir could be expelled after sunset to generate the electricity. Gravity is going to pull the water down at some point anyway.
(Score: 0) by Anonymous Coward on Wednesday February 19 2014, @02:37AM
> The amount of heat produced is finite.
Really? Are you sure it's not infinite..?
(Score: 5, Informative) by mrcoolbp on Monday February 17 2014, @03:12PM
Looks promising, but there is the issue with what to do with all the toxic salt being extracted.
http://www.kcet.org/news/rewire/science/in-talk-of -solar-desalination-theres-a-salty-elephant-in-the -room.html [kcet.org]
(Score:1^½, Radical)
(Score: 2) by edIII on Monday February 17 2014, @03:28PM
It's close to Nevada. Put in that cluster *%&$ of a project that was supposed to store nuclear waste.
(Score: 2, Interesting) by Phoenix666 on Monday February 17 2014, @03:50PM
If brine remains after solar thermal has evaporated water, can't you flush the brine with fresh seawater? The brine returning to the ocean will quickly be rediluted in solution, and we get a fresh volume of seawater to desalinate. If you can extract useful products from the brine directly, then so much the better--their sale can be used to defray the operation costs of the plant.
(Score: 3, Informative) by mrcoolbp on Monday February 17 2014, @03:56PM
So you suggest we just dump toxic salt into the ocean? Doesn't seem like a great idea....
(Score:1^½, Radical)
(Score: 2, Insightful) by weilawei on Monday February 17 2014, @04:06PM
The successor to global warming: Global Salting. Anyone want some tinned fish?
(Score: 2, Informative) by VLM on Monday February 17 2014, @04:51PM
They used to dump the saltwater into the nearby river but that'll salinate the river and kill everything downstream, so that's now a non-starter.
I did some google maps research and they'd need a 60 to 80 mile pipeline or canal (two of them) to get access to the sea shore.
Its probably a heck of a lot simpler and cheaper and more productive to simply move your farm out of the desert and into the great lakes area. No shortage of water or land here. Just keep the water in the same watershed.
(Score: 2, Insightful) by dry on Monday February 17 2014, @11:09PM
Its probably a heck of a lot simpler and cheaper and more productive to simply move your farm out of the desert and into the great lakes area. No shortage of water or land here. Just keep the water in the same watershed.
Seems it would be hard to grow things like oranges around the great lakes and a short growing season for other crops. Might have to go to more greenhouses eventually which will expand the areas where farming is profitable.
https://en.wikipedia.org/wiki/Inverted_totalitari
(Score: 1) by demonlapin on Monday February 17 2014, @05:43PM
You could use it to boost oil production... (runs and hides)
(Score: 4, Informative) by Angry Jesus on Monday February 17 2014, @06:04PM
The brine returning to the ocean will quickly be rediluted in solution
That's the environmental engineering equivalent of a "mere matter of programming."
Even minor variations in salinity can have extreme effects on the local ecology.
(Score: 2, Informative) by gallondr00nk on Monday February 17 2014, @03:57PM
Excellent article. In this case, TFA mentions that it uses molten salt as a heat store in order to run the process 24 hours a day. I also wonder what will be done with the other waste products?
There's also this, quoth TFA:
"Brent Giles, a senior analyst at Lux Research, said solar thermal desalinization's competitiveness with reverse osmosis remained to be seen."
It'll be interesting to know how good the commercial product will be. The pilot looks exciting, but can't produce enough water for a single acre.
(Score: 5, Interesting) by istartedi on Monday February 17 2014, @05:39PM
Save the Salt [savethesalt.org] might be the answer if the toxic elements can be removed. There are plenty of salt flats in the West. As long as the salt from desalination isn't any more toxic than the existing flats, that seems like a natural place to dump it.
(Score: 3, Insightful) by Khyber on Monday February 17 2014, @06:55PM
Thankfully, most of those toxic salts are toxic in heavy concentrations.
Some of the really bad stuff is easily separated out with a centrifuge, the rest of the stuff could be easily converted over into something like SEA-90.
Everything is usable. Right down to the extracted mercury.
Destroying Semiconductors With Style Since 2008
(Score: 5, Informative) by davester666 on Monday February 17 2014, @03:15PM
Of course there is plenty of clean water available to oil companies for fracking.
Almost 50 BILLION gallons of water in Texas alone [since 2011].
http://www.theguardian.com/environment/2014/feb/05 /fracking-water-america-drought-oil-gas [theguardian.com]
(Score: 1) by mhajicek on Monday February 17 2014, @03:55PM
No Tank Girl comments yet?
(Score: 2, Informative) by Angry Jesus on Monday February 17 2014, @09:54PM
I not a fan of fracking, but that article didn't do a very good job of communicating the sense of scale.
The only comparison they made was to the water usage of the city of Boulder - they said 6bn gallons for all fracking in the state of Colorado which is equal to 2x Boulder's total water usage.
But compared to Denver's total water usage (80bn gallons) it ain't so much.
http://www.denverwater.org/AboutUs/KeyFacts/ [denverwater.org]
(Score: 5, Insightful) by The Mighty Buzzard on Monday February 17 2014, @03:23PM
123
456
789
(Score: 1) by regift_of_the_gods on Monday February 17 2014, @03:27PM
But you might care about this [huffingtonpost.com]
(Score: 1) by The Mighty Buzzard on Monday February 17 2014, @03:37PM
Not especially. I make my own wine or drink locally produced vintages. I could never bring myself to drink something from California or France.
In any case, no HuffPo story is ever likely to change my opinion on anything. They're the e-version of Fox News for the left.
123
456
789
(Score: 0) by Anonymous Coward on Monday February 17 2014, @03:44PM
Why are we farming in the desert, and then transporting the produce across an entire continent? Why is it apparently cheaper to do all that, than just grow locally?
(Score: 3, Funny) by The Mighty Buzzard on Monday February 17 2014, @03:59PM
123
456
789
(Score: 1) by demonlapin on Monday February 17 2014, @05:48PM
(Score: 2, Informative) by Walzmyn on Monday February 17 2014, @07:11PM
Farming needs good soil, good climate AND good water. This area had all three by way of water resources from the north until more and more (and more) people moved in and the water was diverted.
Farmers were there first.
(Score: 1) by bigjimslade on Monday February 17 2014, @09:33PM
very much so. people fail to realize that you need a perfect combination of all three in order to make large scale agriculture work. california's central valley has it, except for now they're running out of water, for the time being. good volcanic mineral rich soil (the sierras), good climate (it's california), and water (from the sierra snow pack).
Remember, Tuesday is Soylent Green Day
(Score: 0) by Anonymous Coward on Wednesday February 19 2014, @02:34AM
(Score: 5, Interesting) by Khyber on Monday February 17 2014, @03:27PM
Secondly, the problem is that the majority of our water is used for agriculture. Traditional land agriculture is extremely, wasteful as far as water is concerned. It takes 100,000 gallons of water to produce an acre of fodder grass for livestock.
Of course, we've got a solution for that, as well.
*DISCLAIMER: I AM HEAVILY INVOLVED WITH THE COMPANY YOU'RE ABOUT TO SEE*
Enclosed vertical farms like this [youtube.com] can occupy 1/8 of an acre and only use 1,000 gallons to produce the same amount of fodder grass. This same technology drastically reduces the need for space, water, and nutrient waste, and can be entirely solar-powered, with a power generation surplus, depending upon your crop.
The technology and engineering I have today can make this almost a non-issue, with the exception of certain crops (like our nut-bearing trees.)
Destroying Semiconductors With Style Since 2008
(Score: 1) by edIII on Monday February 17 2014, @03:30PM
Vertical farms are an excellent idea. I'm happy to see effort being put into them.
(Score: 1) by takyon on Monday February 17 2014, @04:04PM
I'm also eagerly awaiting the day that vertical farming becomes commonplace.
(Score: 1) by Cactus on Monday February 17 2014, @05:09PM
Very cool. Been wanting to play with similar things at home but can never quite make the time to put it together. Always good to see stuff like that.
(Score: 1) by Khyber on Monday February 17 2014, @06:22PM
Destroying Semiconductors With Style Since 2008
(Score: 2, Interesting) by NovelUserName on Monday February 17 2014, @06:36PM
I think the point of the proposed plant is that distillation is a pretty cheap thing to set up and run compared to filtration methods. I'm guessing the fact that it's power inefficient doesn't quite make up the difference in cost.
I've been intrigued by aquapoincs [wikipedia.org] for a while, so I'm slightly familiar but not an expert. I thought that most of the high-density water-based crop technologies used greenhouses because the costs to locally generate power for grow-lights were infeasible. The other issue with these solutions is the nutrient stock- generating the chemicals for a hydroponic solution, or the fish-food in aquaponics systems means you've just pushed the environmental effects off one tier. For commercial farming this might not be a big downside since they currently use all the chemicals anyway, and waste a bunch of water on top of that.
(Score: 2, Insightful) by Khyber on Monday February 17 2014, @06:59PM
The costs of LEDs have come WAY down, their efficiencies have gone WAY UP (hovering at 50% efficiency power in/light out) and the feasibility of solar powering the entire thing is better than good. That much has been solved.
Pushing the environmental effects off one tier may not be necessary. The desalination plant itself could use the harvested salts and make fertilizer from them (after a bit of centrifugal processing to remove many of the heavier metals) and have another useful product. Look up SEA-90 to see what I mean.
Destroying Semiconductors With Style Since 2008
(Score: 5, Interesting) by SurvivorZ on Monday February 17 2014, @03:37PM
California is so dry that the ocean is receding [/sarcasm].
Most of my parents' neighbors have resulted to ripping up their grass and converting their yards into rock gardens, which is much more apropos for the climate than the water-hungry Bermuda grass.
The HOA is having a fit, tho.
(Score: 5, Insightful) by cwix on Monday February 17 2014, @03:52PM
HOA too often cause more problems then they solve.
(Score: 4, Interesting) by Vanderhoth on Monday February 17 2014, @03:54PM
Grass looks nice, but it's a pain to keep healthy. I just grow weeds instead. Actually violets and clover are really nice. Clover especially gets soft and think with no extra work. I don't have to do anything to them and they don't get very tall so less mowing in the summer.
I have one or two weeks a year where my yard is embarrassingly yellow from dandelions and I have to mow them down every other day, but otherwise it's not bad. I feel bad for my neighbor who spends 3+ hours a day, 6+ hours on weekends, caring for his lawn. Probably because of the jerks in the neighborhood that let their dandelions grow and go to seed. The first year I owned my house I spent every waking moment (rain or shine) out in the yard pulling dandelions, I had my yard looking really good, then I noticed the guy across from me just let his yard go to seed. The dandelions grew back with a vengeance the following year.
"Now we know", "And knowing is half the battle". -G.I. Joooooe
(Score: 3, Insightful) by hemocyanin on Monday February 17 2014, @04:41PM
Dandelions are flowers. Why does everyone hate flowers so much?
(Score: 4, Interesting) by Vanderhoth on Monday February 17 2014, @05:04PM
I like them. I made a good wine with the crop from year two. The dried roots make good coffee.
"Now we know", "And knowing is half the battle". -G.I. Joooooe
(Score: 3, Informative) by dry on Monday February 17 2014, @11:19PM
They're also really good for the ground. The tap roots break through any layers of hard pan and such and reach into the subsoil. This brings nutrients up and also creates passages for earthworms which then also brings up nutrition. Helps keep oxygen in the soil as well. Roots need oxygen.
As well as mentioned the flowers are good for wine, the leaves and roots are edible though bitter.
https://en.wikipedia.org/wiki/Inverted_totalitari
(Score: 1) by Cactus on Monday February 17 2014, @05:13PM
A lot of Cali lawns are going to look like AZ and NM lawns pretty soon, I think.
(Score: 1) by eravnrekaree on Monday February 17 2014, @05:09PM
I had thought of this idea myself, of using sunlight to directly desalinate water by some means, such as distillation. I am glad that this idea is being put to use. It would help cut down on fossil fuel usage to provide the water source. It would seem even consumer devices could be marketed to produce clean water with solar energy.