Slashdot Mirror
California City Considers Restarting Desalination Plant To Fight Drought
First time accepted submitter SaraLast (3619459) writes in with news about Santa Barbara considering the restart of its desalination plant. "This seaside city thought it had the perfect solution the last time California withered in a severe drought more than two decades ago: Tap the ocean to turn salty seawater to fresh water. The $34 million desalination plant was fired up for only three months and mothballed after a miracle soaking of rain. As the state again grapples with historic dryness, the city nicknamed the "American Riviera" has its eye on restarting the idled facility to hedge against current and future droughts. "We were so close to running out of water during the last drought. It was frightening," said Joshua Haggmark, interim water resources manager. "Desalination wasn't a crazy idea back then." Removing salt from ocean water is not a far-out idea, but it's no quick drought-relief option. It takes years of planning and overcoming red tape to launch a project. Santa Barbara is uniquely positioned with a desalination plant in storage. But getting it humming again won't be as simple as flipping a switch."
Now I never really looked into it, but it sounds easy. Too bad the people working on this aren't as smart as me.
Farmers in the desert use about 20 times as much water as California urbanites.
Agriculture in the southwest (i.e. in the desert) is being killed by the lack of rainfall, which seems to have caught everyone by surprise. They're idiots first, farmers second.
Chuuch. Preach. Tabernacle.
I hope you are ready when the population of southern California moves to where the water is. Don't worry, they will bring some "cool" with them. It will have to be an improvement.
It's that little bit about boiling the water. Converting water from liquid to gaseous phase (aka boiling) is energy intensive (read:expensive). To go from room temp water (we'll say 20C) to all of it vaporized and ready for condensation takes about 0.72kWh for each liter of water. So before you run the plant, pump the water, cool the condensate, and prep it for delivery, you've got that much energy going in. Even if you had no other costs, and you paid the lowest (tier 1) residential rates from So Cal Edison, you're looking at $0.36/gal for water. Add processing, markup, delivery...you're north of $1/gal, I'd bet.
Of course, that's why they don't generally use distillation, but even in your scenario the cost of "just boiling the water" adds up very, very quickly.
Is it just my observation, or are there way too many stupid people in the world?
easy, you merely convert the unwanted removed salt to energy. duh!
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
> Rather, it is all about killing agriculture in the southwest to free up more water for California urbanites.
Agriculture uses about 70%, with industry using 20% and urban populations using 10% of the water. Agriculture, you know, that stuff you eat from those greedy bastards in California.
> Nevada rancher stand off...
Bullshit. It's about some welfare rancher not paying his grazing fee's. Pure and simple. He has no intellectual or legal argument, so he is whipping up the dummies over on Fox News to call out the Tea Party morons to protest his desire to rip off the Tax Payers.
Linux O Muerte!
To me all you need to do is boil water to strip the salt, you sell the salt and the water back.
The difficulty is not the ability to do it, it is that the energy requirements make it economically uncompetitive. Boiling that much water and then collecting the condensation generally takes a LOT of energy which is quite expensive in most cases. Places with a desert like climate and abundant energy resources (like the Middle East) can result in desalinization plants that are economically sensible but in much of the world it's just not competitive. Theoretically you could have a nuclear powered desalinization plant that might be economically competitive but I'm not aware that anyone has done this yet.
you sell the salt and the water back.
Doesn't work when it cost you more to get the salt and water than it costs to truck/pipe it in from elsewhere. Salt in this case is a byproduct but you wouldn't be able to sell it profitably or even on a breakeven basis given current prices in most places. Same with the water if it is being sold to farmers. It makes their crops economically uncompetitive with those from areas not experiencing drought.
Obviously it is more proccessing, and more expensive than getting just ground water or rain water because of that but how much more expensive can it really be?
Consult wikipedia for a quick answer.
could it not be done in a way where we use the salt water in a new type of energy generating plant, that collects the steam and makes it usable?
There are waste heat desalinization plants being experimented with.
Much WISER would be to deny frackers the CLEAN POTABLE WATER they pump deep into oil fields to get their 1 barrel of oil per 10 barrels wasted water.
1) I sincerely doubt the oil companies use the same water that you get from the tap to do that.
2) Southern California is a semi-desert anyway... always has been, always will be (well, within the next few centuries, anyway).
3) If they hadn't been so busy diverting existing water to save some obscure and hyper-local species of fish...
Quo usque tandem abutere, Nimbus, patientia nostra?
They might also ask Northern California to perhaps stop shipping a whole bunch of water to China in the form of really cheap Alfalfa..
Sleep your way to a whiter smile...date a dentist!
....someone's going to figure out that the problem here is " It takes years of planning and overcoming red tape to launch a project. "
Seriously?
Why?
If the state simultaneously refuses to constrain growth within their water resources, and cannot GTFO of the way of communities *solving* the water resource limitations themselves, does anyone see there's a contradiction there?
-Styopa
They are using the same idea this time. Spending millions of dollars on a desalination plant will cause droughts to end.
2) Southern California is a semi-desert anyway... always has been, always will be (well, within the next few centuries, anyway).3) If they hadn't been so busy diverting existing water to save some obscure and hyper-local species of fish...
These two arguments contradict one another. If it's a desert then realistically they shouldn't have been diverting the water that said fish depends on in the first place. It only became an issue because water was diverted that shouldn't have been. You don't build stuff or farm in a desert when you don't have to. Las Vegas and Phoenix should not exist in anything close to their current form.
Much WISER would be to deny frackers the CLEAN POTABLE WATER they pump deep into oil fields to get their 1 barrel of oil per 10 barrels wasted water.
Um... The amount of potable water used by frackers is such a low fraction of available water that this is almost laughable. There is many times more water wasted in a day because people won't fix their leaky toilets than the frackers use in a whole year.
If your goal is to save water, I suggest you outlaw watering grass using sprinklers that spray water. Mandate drip irrigation and make sure people are maintaining their plumbing properly. You got to start where the waste is the biggest, or your efforts are a joke.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
This should of been done 50 years ago. Various California water districts have been doing it for quite some time: http://www.acwd.org/index.aspx... Just not on large scales.
Much WISER would be to deny frackers the CLEAN POTABLE WATER they pump deep into oil fields to get their 1 barrel of oil per 10 barrels wasted water.
That barrel of oil is worth $100. The ten barrels of water were worth about $1. A better idea would be to get the government out of the business of "picking winners" by micromanaging the allocation of water through idiotic subsidies that result in tens of thousands of acres or rice growing in the desert. California doesn't have a shortage of water, we just have an excess of stupid policies.
They honestly see resource shortages as a good thing, because the modern technological lifestyle is inherently evil.
Nice strawman, but... No.
No one (sane) considers resource shortages a "good" thing. Resource pressure, on the other hand, helps to prevent actual shortages.
When you have a free and unlimited open faucet, you use water for any old thing that comes to mind - Drinking, bathing, slip-n'-slides, washing the car, making rainbows with mist, growing a climate-inappropriate groundcover plant, whatever strikes your fancy.
When you have a $200/month water bill associated with that faucet, you damned well make sure it goes to the necessities, and you find a way to shower in under five minutes.
And when you get a ration of one gallon of water per day - You use it for drinking and cooking, period.
Conservationists "like" situation #2 solely because it prevents us from getting to #3. Unfortunately, we have, historically, artificially created the appearance of situation #1 even in the middle of a frickin' desert thanks to activities like draining the Colorado river dry (and the resulting downstream environmental disaster, as well as not-so-slowly depleting continental aquifers that take millennia to refill (ask Florida what happens when those get too low).
In a universe where you can really make infinite energy and infinite water and infinite food - Waste all you want! But in our universe, TANSTAAFL.
I never looked into it but I always hear how expensive it is to run these things. To me all you need to do is boil water to strip the salt, you sell the salt and the water back. Obviously it is more proccessing, and more expensive than getting just ground water or rain water because of that but how much more expensive can it really be? also, could it not be done in a way where we use the salt water in a new type of energy generating plant, that collects the steam and makes it usable?
Reverse osmosis is a whole lot cheaper, energy wise, than distillation. The original plant was of the Reverse Osmosis type.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
Desalination plants don't boil water to filter the salt out. They use reverse osmosis, which typically requires about 3 kWh of electricity per cubic metre of water processed due to the very high pressure pumps required to force the water through the filters.
I could always predict when it would rain when I lived in Los Angeles. It was always the day I decided I would go to the beach.
So PLEASE move back to LA and plan to spend your first month on the beach...
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
1) It's unlikely there's significant amounts of radiation after having been diluted with the entire Pacific Ocean.
2) Even if their were, it would be removed during the evaporation process, as it's unlikely this plant is going to be operating at a temperature sufficient to boil heavy metals
The hilarious part about the situation is the amount of overlap between conservationists and socialists.
"Water needs to be free (subsidized) because it's a human right!"
"Oh shit, when we artificially lower the price of things people use too much of those things. Since it was our attempt to micromanage resource allocation that caused the problem in the first place, we better double down with even more micromanagement by implementing rationing so that everybody will stop using as much of the resource that we forcefully made too inexpensive."
As has been pointed out, desalination plants don't typically use distillation, they use reverse osmosis. That is to say that they use very high-pressure pumps to force the water through a membrane which rejects salt. Energy consumption is currently at about 3 kWh per cubic metre, although that's falling over time was membrane technology improves (the less pressure required, the lower the cost).
That works out to about 3 watt-hours per litre. Where I live, industrial power rates put that at $0.0001056 CAD per litre. Or $0.1056 CAD per cubic metre of water (thousand litres) if you prefer.
Obviously, if you live in a place that charges more for power (industrial power is $0.0352 per kWh here), that cost goes up.
So let me get this straight...
The Sahara, which has existed for a few thousand years, is a result of the commodities market, and the solution is to just pump water in from the Mediterranean, using the minute amount of usable energy extracted from wave action, with a machine that's big enough to supply water to the whole desert, yet cheap enough that there won't be a "disagreement over the price"?
Sounds simple enough.
You do not have a moral or legal right to do absolutely anything you want.
Removing salt from ocean water is a big thing to set up, but don't forget that in addition to getting drinking water, you also get electric power out of the operation as well.
Actually this isn't as off the mark as it seems to be. A nuclear power plant could double as a desalinization plant. But no one seems to like nuclear power plants.
No? It's exactly the reverse. This takes *HUGE* amounts of energy.
Electricity is one form of energy used to power desalinization but certainly not the only form. But you are correct in that the use of electricity to desalinate is not very efficient. A focused solar lens array much like the ones used in solar electric production would be more efficient AND the resulting steam could actually be used to produce electricity as a byproduct. Not enough to be considered an electric generation facility but something is better than nothing.
"A person is smart. People are dumb, panicky dangerous animals and you know it." - K
Well if you have the choice between dying of thirst or paying $80 for a cubic yard, you'd probably pay the $80.
A cubic yard is A LOT of water. You could live for some time off of that.
And, probably at that cost it makes sense for people to bring in water by the tanker truck, pushing prices down.
The key is what you're using it for. If you just want something to drink, $80 per cubic yard is quite all right. If you want to take a desert and turn it lush and green, it's quite expensive.
Seems to me people should look at usage case more than anything else.
... or you use pumps to pressurize a bunch of salt water and use a membrane to filter out the salt. Again pressurizing the water consumes a lot of energy.
Couldn't you just drop a container into the ocean, one with only two openings - one with your membrane for salt water in, the other opening for desalinated water out? The deeper you put it, the more pressure outside the container that pushes the salt water through your membrane. Then you could use a low power pump to slowly remove the clean water through a hose attached to the other opening.
A recursive sig
Can impart wisdom and truth
Call proc signature()
I never looked into it but I always hear how expensive it is to run these things?
In short, absurdly expensive. So expensive it became economically impractical after running for 3 month as the '92 El Nino made relatively cheap reservoir water available again. With the odds of a strong El Nino climbing this year it looks like we are set for a repeat of that expensive debacle.
Feast and famine of rainfall is a fact of life that politicians seem incapable of grasping. It has always been this way. Average and water-poor years followed by strong El Ninos, which reset the reservoirs and snowpack roughly every 10 years. Budgeting water better between El Ninos should be trivial, yet....
I'm soooo looking forward to someone in California realizing that their seawater is connected to the seawater outside of Fukushima Daiichi ...
LOL, Yea, I love this kind of thing. Just because we can MEASURE the radiation in something means that it is a deadly poison.. Never mind that the yearly exposure is an order of magnitude or two less than what you'd get say in one airplane trip... You are right though, there will be protests the day before they turn on the switch (after the money is spent) claiming it's "not too late!" .
You say RADIATION and the poor uninformed public run like scared sheep to put a stop to that deadly menace to society, science and medical experts aside.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
There is no link between water pumped into the ground for extraction and drinking supply. None What So Ever.
The Kruger Dunning explains most post on
The Saudis are planning to build out a lot of nuclear power stations over the next couple of decades which along with solar thermal power plants will be used to power desalination plants currently fuelled by oil and gas. Other Middle eastern nations are planning similar facilities, some of them combined nuclear power generation and desalination systems utilising the "waste" heat from the reactors.
In 2012, California received 88 cents in federal spending for every dollar paid in federal taxes. If the state were greedy, that number would be over a dollar.
Idiots? Probably. Greedy? Probably not.
Any sufficiently unpopular but cohesive argument is indistinguishable from trolling.
That would be hoprrid.
That means some rich guy will dictate who gets water. What's that? CA votes dem? well, no water for you.
The Kruger Dunning explains most post on
Since when does RUNNING A FUNCTIONAL RANCH WITH YOUR OWN HANDS count as "welfare" on this planet?
When you're doing it on somebody else's land without compensating them?
To put a partisan twist on this: The urban areas are the heavily democratic areas. The desert farmers tend to be GOP supporters. Who are the real welfare queens? See also: Bundy.
If you were me, you'd be good lookin'. - six string samurai
One of the challenges for renewables like wind/solar is being able to generate power when the grid doesn't need it.
Maybe instead of stopping the windmills they should keep them spinning but use desal plants as a power sink for the "excess" power. It's by and large free energy they wouldn't even generate; you might as well generate it and use it to do useful work.
It's debatable whether the excess energy could desal enough water to make a difference.
Desalination plants don't boil water to filter the salt out
Incorrect. Quite a few of them do boil the water. Some through vaccuum distillation which lowers the energy requirements but it still is boiling the water. Reverse osmosis is the principle competitive technology to distillation methods but both exist.
It's a reverse osmosis plant. If if filters out Na+ and Cl- ions, it will also filter out any of the larger particulate that might be radioactive. If you sit a sealed bottle of distilled water next to a nuclear reactor for a year, the water inside that bottle will not become radioactive. Let me say this slowly: "Radiation is not a chemical reaction".
"You could live for some time off of that."
No you can't, it's just over 200 gallons.
Unless by some time you mean about a week. You need to drink 1/2 gallon a day alone.
Bath: 40 gallons
Shower: 2.5 gallons per minute
Old showerheads may use 4 gal/min whereas newer low-flow showerheads use about 2.
Teeth brushing: 1 gallon
Depends on if you let the water run while brushing
Hands/face washing: 1 gallon
Face/leg shaving: 1 gallon
Depends on if you let the water run while shaving.
Dishwasher: 20 gallons/load
New energy-efficient models may only use 4 gallons.
Dishwashing by hand: 4 gallons/minute
With a low-flow faucet head, might be 1 gallon.
Clothes washing (machine): : 40 gallons/load (top loading)
Front-loaders may use about 20 gallons/load.
Toilet flush: 3 gallons
Older models may use more, but new energy-efficient toilets might only use 1 gallon/flush.
Glasses of water drunk: 8 oz. per glass (1/16th of a gallon)
Did you drink your "eight glasses of water" today?
The Kruger Dunning explains most post on
When you demand the government subsidize you with free grazing land because you don't own enough land to raise your cattle without it? It is similar to the government subsidizing people with kids with food stamps because they don't have the money to feed them. Whats the difference?
The system is inefficient for how much work is put into it versus the water output.
Ok, so that's for a hand-built survival system... perhaps not a good reference for a purpose-built system.
In 1952 the United States military developed a portable solar still ...a large inflatable 24-inch plastic ball that floats on the ocean... on a good day 2.5 US quarts (2.4 l) of fresh water could be produced. On an overcast day, 1.5 US quarts (1.4 l) was produced.
The plant in question produces 7500 acre-feet (2,400,000,000 US gallons) per year. That's the equivalent of 18 million of the spheres. If we assume that the barge would have similar efficiency (which it probably wouldn't, as there would be significant thermal loss to the ocean below, as opposed to the military's encapsulation design), we would require a sunlit area of approximately 8.1 billion square inches, or 2.0 square miles. That's about 360 times the area of a giant cruise ship.
"Inefficient" still seems like the right word, and we still don't have any answers regarding how to propel or maneuver that large a mass.
You do not have a moral or legal right to do absolutely anything you want.
"while burning through resources at an unsustainable rate, is going to make the concept of money look like a complete fraud, within the next generation.
haha, there has been a douche bag making that claim every generation since the dawn of civilization.
The Kruger Dunning explains most post on
Why can't food be grown in the Great Plains instead of the Mojave Desert?
It is grown there. However we're draining a lot of the aquifers in the Great Plains too since we plant crops like corn that use a LOT of water.
Aquifers in Minnesota aren't doing all that well (no pun intended) either. My family home is on White Bear Lake, which has become something of a cautionary tale for careless groundwater pumping combined with wetland drainage in order to make $millions for developers and then shaft the people who've lived there for generations.
Perscriptio in manibus tabellariorum est.
As soon as the pressure equalizes between the two sides of the membrane the flow of water will stop. Your pump will have to do all the work to pull the water through the membrane at the point. It's now also going to have to fight gravity to pump the water from the depths of the ocean.
>Farmers in the desert use about 20 times as much water as California urbanites.
Not quite. 80% is ag, 10% residential, 10% industrial.
In exchange, California earns about $17B from farms just in the San Joaquin, and supplies half the fruit in the nation.
Consumption -> energy use -> global warming -> worse droughts -> desalinization -> energy use ->->-> This is a very poor long term solution
How is that any different from a groundwater well? How are those cost effective and is method isn't?
No you can't, it's just over 200 gallons. Unless by some time you mean about a week. You need to drink 1/2 gallon a day alone.
By my calculations, 1/2 gallon a day means 200 gallons would last 400 days. More than a year. But, as you point out, there are other uses.
To put back some of the context, the person you replied to said: "Well if you have the choice between dying of thirst or paying $80 for a cubic yard, you'd probably pay the $80."
Teeth brushing: 1 gallon
If it takes you more than a cupful of water to brush your teeth, you are wasteful and Darwin says you will not survive. But you don't need to brush your teeth to keep from dying of thirst.
Face/leg shaving: 1 gallon
I'm not sure how this is a requirement to keep from dying of thirst. Personally, I've not shaved my legs ever, and my face has been blade-free for more than 20 years.
The rest of the uses you come up with in your list are hardly survival requirements. The only one is the 1/2 gallon a day for drinking. Even adding a 1/2 gallon for cooking means you could get by for 200 days on that 200 gallons. No, it wouldn't be pleasant, but it would keep you from dying of thirst.
My current city water bill is about $40/month. $80 for water that would last for just six months means I come out ahead on the deal.
That barrel of oil is worth $100. The ten barrels of water were worth about $1.
All hail the almighty dollar!
When the well dries, you shall drink pennies!
When the food does not grow, you shall eat quarters!
When the air becomes polluted, you shall breathe stocks!
Mandate drip irrigation and make sure people are maintaining their plumbing properly.
That's easy to fix : put water meters at every house and make people pay per-gallon. You'll see people fixing their plumbing the day right after they receive the first bill
Avoid the MS tax, always buy I.B.M. PC's (I Built-it Myself)
Simple, the pressure doesn't equalize until the water inside the cylinder rises to the level of the water outside; then the pump just sucks the water right off the top of the inside of the cylinder, lowering the inside level and forcing more water through the membrane.
My apologies. Farmers in the desert use about 8 times as much water as California urbanites. Of course, if you look at per-person usage, it's probably hundreds of times more water, but there's no need to go down that road.
Anyway, California's gross state product is right around $2T, which suggests that those farms in the San Joaquin account for less than one percent of California's economy. It's a rounding error. Any economic argument is bound to fail here, as agriculture is virtually meaningless in this context.
As far as supplying half the fruit in this nation, are you suggesting that without insane subsidies it would still be cheaper to farm in the Californian desert than to simply import fruit from actual arable land? I find that hard to believe, and you haven't offered any convincing evidence.
Chuuch. Preach. Tabernacle.
I'm not trolling. I just don't think you understand the scale of the problem.
To give the entire Sahara 28 inches of rainfall (which is the low end of what Iowa gets annually), you need 5.4 billion acre feet of water. By mass, that's 67 times the total amount of oil produced since 1850*. If you think the water business is the problem now, just wait until you see the management for that size of operation.
So where exactly do we get these 15,000,000,000,000,000 pounds of water? We could drain half of Lake Superior, but you specified rain barrels. That makes the math easy. Cherrapunji is often regarded as the wettest place on Earth, recording 1,041.75 inches of rainfall in a calendar year, which is 37 times what Iowa gets. That means we'd only need to cover an area 1/37th the size of the Sahara to get enough water, assuming it all has the same rainfall as Cherrapunji. Our total rain-barrel area is then only about 95,000 square miles, which would cover about half the area of France.
I guess you're right: The problem is politics and business. No government or corporation wants to try to build a rain-barrel raft half the size of France (or larger, since it won't all receive 1000 inches of rainfall per year).
* Wolfram Alpha is great for perspective.
You do not have a moral or legal right to do absolutely anything you want.
That means some rich guy will dictate who gets water.
Under the current system, rich farmers get subsidized water, while poor people in the cities pay high rates to fund those subsidies. It is almost inconceivable that any market based system could be more unfair than the current system designed by politicians.
What's that? CA votes dem? well, no water for you.
California as a whole votes Dem. Most of the Central Valley, which receives the water subsidies, votes Rep.
I guess the initial costs might be quite a big higher than just getting a pump and a semi-permeable membrane.
It takes an average of 3kwh to desalinate 1 m^3 of water via reverse osmosis. Per this report it's 4-12 kwh of thermal energy to distill 1 m^3, plus 1.5-3.5 kwh of electricity.
If we figure on 10 kwh of thermal and we're setting stuff up so that we're down near 1.5 kwh of electric*, then consult a solar map, we're looking at needing 2-3 m^2 of collector per m^3 of production a day(at 90% or so efficiency), and it only cuts electric costs in half.
That's 264 gallons of water/day, roughly enough for 2.5 people. Household useage, not commercial or industrial.
Please note that these are using near optimal assumptions, I wouldn't be surprised if you need 2-10 times as much collector as what I've estimated.
*Pumping and such.
I don't read AC A human right
Unless you can demonstrate that the oil companies are hauling water from Santa Barbara to frack wells in other parts of the country, I don't see how this is relevant.
Besides, I think what you are describing is an oil recovery technique, not fracking. There is a process were water/steam is injected into old wells to try and recover more oil/gas, but it has little relationship to hydraulic fracturing
The majority of water in Santa Barbara is derived from local sources. While there is a lot of local agriculture, it is primarily on coastal planes, not in classic desert areas like Imperial Country. In our current year we've had less than half our typical rainfall, and it has has been going on like this for three years now. Our last drought, when the desal plant was first built, took seven years to set in, we've reached the crisis point in this drought much more quickly. My point is I don't think we're quite as dumb as the rest of the state where they can't ever manage on local sources in normal years, we can. But when things go dry quickly like they have, we get caught out. Of course building a desal plant in an emergency is actually a rain dance. It worked perfectly last time, and given the predictions of an El Nino for next year, it should work this time as well.
"This mission is too important to allow you to jeopardize it." -- HAL
...then you missed the entire point of his post.
So what you are objecting to the the Practice of Water Rights
Water Rights are a legal principle, not Federal Micromanagement. The water belongs to the person with the oldest rights to it first. Need isn't part of the equation.
The person who's water rights were established in 1849 have priority to the person who's water rights were established in 1999.
First come first served. Water Rights are inheritable and sellable. Those farmers have water rights that are older than the residents in the Cities. That is why they get first dibs. Not because they are propped up by the Federal Government. But because the process of water rights was established by Common Law, and supported by California and Federal Courts.
So where's the water come from? The same nearby rivers that the local towns pull drinking water from? Or do the frackers have windtraps?
Learn to love Alaska
Their mothballed desalination plant won't be a reverse osmosis system. It will be an older flash distillation plant.
Probably steam powered. I ran and supervised the operation of 2 multi-stage 100,000 gallon per day flash distillation plants in the Navy. They have very few moving parts and were very reliable. They just took a ton of steam to operate. Steam for the ejectors that pulled the vacuum, and steam for the heating elements. Lots of electricity for the pumps.
But they are talking about a plant that can produce millions of gallons per day of fresh water. It will be very clean and soft too. Expect 0 hardness on the output. They probably will be adding minerals so the output has good flavor.
Desalination is usually done by reverse osmosis. You need a pump of some description to do that. A solar array could provide the electricity to run the pump or power some sort of steam engine.
The hilarious part is conservatives who don't understand that the eeeeeevil regulations are less expensive to comply with than accepting what the market rate would be with no intervention.
This doesn't make any sense physically.
Lets say you go moderately deep, and have a pressure differential of 10 atmospheres (say 11 atm on the outside, and 1 on the inside). The pressure differential causes water to be pumped into the container until there is no pressure difference and the water flow stops. To restore the pressure differential you need to pump the water out - so you'd need the pump to provide 10 atm of pressure to evacuate the chamber.
At that point, why not just have a pump here on the surface to provide the 10 atm of pressure and not deal with the hassle of pumping it up from under the ocean needlessly? You negate the energy gained from the ocean depths by bringing that water back up the surface.
This is magical thinking where you coast your bike down a 10 foot ramp and expect to go 20 feet up on the other side.
Yes, and so many are anti-conservation because they confuse conservation with socialism. If you have to use resources responsibly, then the communists have already won.
Learn to love Alaska
eehhhhhhh. Sorta.
The western halves of Nebraska, the Dakotas and Kansas are all half-way to being deserts with rolling sand dunes and all. They need irrigation to support crops. Otherwise they're just grazing land. And not great at that either.
The Ogallala aquifer which happens to be right in that area is indeed shrinking and it's a worry. Conservationists are like "OMG WTF!? that took thousands of years to accumulate" and farmers are like "It's been making my family MONEY for decades, we aint' stoppin". It's an issue for a sizable strip of land, but it most certainly doesn't apply to the majority of the "Great Plains".
The eastern half of those states, all the way to the Appalachian mountains, are plenty wet to support crops without the need of irrigation. Iowa has a "thriving" wine industry in the northeast in a strip of land that avoided being glaicered way back when so it's "weird" by our standards. And there are plenty of apple orchards. Johnny Appleseed is still legendary around here. But certain crops simply need a different climate. You're not going to have a... uh... banana industry in Minnesota.
All in all the USA has a fantastic piece of land for agriculture use and we could grow enough food to end world hunger. But getting it from the fields to hungry mouths has some logistical issues and so we grow feed corn to feed our cattle just so it tastes better. If we every really wanted to be super-dicks to the rest of the world. We'd unleash our capabilities, flood the markets with cheap food for a decade or until everyone else's agriculture industries collapsed and then simply stop making shipments. The Arab spring started with food riots.
For goodness sake;
Just spray the damned water in a wind tunnel, use a baffle filter to catch salt crystals, then re-condense using a venturi.
Evaporation is a factor of ambient temperature, pressure, and surface area. Meddle with any one of those three and you alter the vapor point of any liquid.
This is not hard, but people like to act like it is.
(For the imaginatively impaired, here's what you do:)
1) spray the raw sea water through a tiny misting nozzel inside a wind tunnel that blows up a vertical shaft with textured baffles inside.
The misting process radically increases the surface area of the water by turning it into suspended droplets in the air. This radically increase the amount of evaporation that happens at the ambient temperature, causing a marked reduction in local air temperature as energy is transferred to water molecules to create vapor. this leaves tiny salt crystals in the air. The active agitation caused by the forced air in the wind tunnel further enhances the evaporation of the water.
The baffles capture what remaining moisture droplets are still suspended on the air currents, wetting the textured surfaces, and creating a "Sticky" surface for the salt crystals to adhere to. several such baffles capture the majority of these airborne salt crystals. these surface accrete the salt, which rapidly grows a thick rind on their surfaces.
the tall stack of the vertical wind tunnel helps ensure that only the tiniest microparticulates of salt crystals can remain airborne at the top of the stack, as gravity pulls down on the heavier crystals, making them favor being lower down in the stack.
2) The air is pulled into the "inlet" port on a venturi, which is driven by an outside air source. The sharp reduction in pressure radically reduces the vapor point of any still persistent water droplets, ensuring evaporation.
3) The resulting water vapor + air mixture is run through a chilled condensator, which precipitates the now clean water out.
(Hint, if you put the condensator coil about 5 meters below the surface of the ocean, the ambient sea temperature is sufficient to get this effect for free. Especially with cold-as-fuck california sea water.)
There is more than enough thermal energy in ordinary summer air to fully evaporate a whole lot of water. Or is running some flipping fans and a pressure pump on the seawater just too much effort?
Incorrect.
Farmers in California's San Joaquin depend on government-provided water. The federal government built aqueducts and channels and so it can control water allocation.
Depends on the grease. Runny grease that's liquid at tap-water temperature isn't an issue. It won't harm your pipes, or any other pipes getting to the treatment plants. It's the thick grease that you have to use hot water to wash down. That'll congeal in pipes (yours or others) as it cools and not wash away, catching other debris (especailly "flushable wipes" that aren't flushable any more than a cotton towel), and eventually forming a pretty formidable clog.
Learn to love Alaska
rich farmers? I have never heard of a rich farmer. Either the farmer makes that season or not. Farming is a lot like the lottery on if your crops grow or not.
You obviously never heard of most of the companies that you buy your food from, then. The financial interests behind the farms are quite well-off. Heck, they and others in the industry paid billions in fines/judgments just over the lysine price-fixing scandal, and they're still in business...
The plant is, in fact, a reverse osmosis plant.
Just because something is perfectly safe doesn't mean that Californians won't be scared of it.
Not a sentence!
You aren't following. Cover the Pacific with a tarp. Pump all the water that lands on it to central Australia. It'll have more water than Iowa. Do the same with the freshwater landing on the Atlantic and Indian oceans to Sahara, and tell me how those calculations go.
Learn to love Alaska
Except that QE is the purchase of investment vehicles (bonds) that return their cost. You're right, though: You're back to your original point where you don't understand economics.
That does bring up a good question, however: What is the price of the water produced with these rain barrels?
If we want to pay back the production cost of one barge in a single productive year, each gallon of water must be sold for only $0.023. The US average price per gallon of water is $0.002, so to compete with the current US market, you'll need to spread the cost over a decade, at least, and we're still assuming minimal production costs and free labor.
Now would be a good time to account for not having that world-record rainfall. The average in a good southern tropical location is only about 100 inches annually, so your barge probably wouldn't break even for 100 years, if it even survives that long. 100 years is a very long time in salt water, even with corrosion resistance. In comparison, the desalination plant would break even in only 7 years.
I'm left with the same conclusion as I had in my earlier comment: No sane politician or corporate investor will want anything to do with a project this absurd. It's not a matter of how you scale up or where you get the water. A giant rain barrel left open to the sky simply isn't a cost-effective means of water production. Small ones only work because they have a relatively large surface gathering water for them.
American rainfall ranges from about 5 inches to 30 inches per year, which (at 10 inches per year) gives us about 12500 gallons per year for a 2000 square foot collection area. Conveniently and coincidentally, that much water costs about the same ($25) as a cheap plastic rain barrel on Amazon. To equal the production of the one desalination plant (7500 acre feet per year), we'd have to gather rainfall from an area of 9000 acres, or half the size of Manhattan. The easiest way to accomplish that scale of collection would be to dam up a valley, possibly diverting existing rivers and tributaries. In short, build a reservoir, like politicians and corporations already have in many places that can fill them.
I've been mimicking Randall Munroe's style all day, so it's fitting that I'm reminded of a basic test for whether an idea makes sense. Building a reservoir on land where there is already ample rainfall makes sense, and people are already doing it. Building a completely man-made structure to gather rainwater for transport elsewhere doesn't make sense, so people don't do it. You can blame conspiracies all you want, but that won't change the basic fact that such a project is a ridiculously expensive way to get water.
You do not have a moral or legal right to do absolutely anything you want.