[Heineken]

I agree that scalability isn't an issue if we're talking about a greatly downsized civilization, aflurry. But that's really the whole point of doomer thinking---that the current civilization will shrink drastically, and pretty fast: that's the very definition of "doom" as I see it.

Cost could be a huge issue, though. And maintenance. If something breaks and the fabrication and supply lines are gone, how do you get the exotic spare parts you need?

The article was exceedingly thin on details, as is so often the case.

I bet we never hear about this scheme again.

[lorenzo]

Found this in French, but Bloomberg has a nice write-up. Just for the Great Peak Oil Archives:

Veolia's Desalination Costs Triple on Energy Prices (Update2)
June 26, 2008. - Veolia Environnement SA, the world's biggest water company, said the cost of purifying seawater has tripled because of higher energy prices, squeezing profit margins.
The cost of producing water from desalination plants may have risen to as much as $1.60 per cubic meter from as low as 50 cents "in the last few years,'' Jean-Michel Herrewyn, chief executive officer of Veolia Water Solutions & Technologies, said in an interview in Singapore yesterday.

Power is the largest cost at a desalination plant, which filters millions of gallons of seawater into drinking water by straining out salt, bacteria and minerals. Industry margins at desalination plants, typically between 10 and 15 percent, are shrinking as fuel costs increase. "The cost curves are going up,'' Herrewyn said. ``If we have to reduce the price of desalinated water, we have to reduce the price of energy.''

Veolia shares fell 32 cents, or 0.9 percent, to 35.73 euros at 1:49 p.m. in Paris today. The stock has lost 43 percent this year, compared with a 20 percent decline in the CAC 40 Index, on investor concern over profit margins due to currency losses and higher cost inflation on water and waste projects. Profit targets may be "difficult to achieve,'' Veolia Senior Executive Vice President Jerome Contamine said in a posting on French financial Web site LeRevenue.com last week.

Low Margins: Crude oil has doubled in the past year and touched a record $139.89 on June 16, while natural gas futures in New York have gained 70 percent this year, pushing up costs of producing electricity. Almost 700 million people in Asia lack access to clean water and about 2 billion are without adequate drainage, according to Manila-based Asian Development Bank.

"Water is a much slower developing market because the margins are low,'' said Lisa Henthorne, president of the International Desalination Association. "We can't charge 50 to 100 percent margins for bulk water because it is still a social good.'' The margins in desalination are between 10 and 15 percent, she said. Even so, sales in Asia's water-purification market will increase by as much as 20 percent in the next three to five years, outpacing the world, Herrewyn said. Veolia may get "very sizeable'' municipal contracts for desalination, reuse and recycling in the range of $100 million, he said.

Rising Pollution: "The booming economies of China and India are very attractive,'' Herrewyn said in a Bloomberg TV interview today in Singapore. "One of the main, if not the leading, growth areas now is the Middle East.'' Rising levels of pollution in developing economies are creating more opportunities for business, Dan McCarthy, chief executive officer of Black & Veatch Corp., a U.S. engineering and construction company that provides water-treatment services, said in a TV interview today. "We do focus on the hot developing marketplaces because they do have challenges from very basic needs,'' McCarthy said. The public is "looking at sustainable solutions more aggressively than they had before.''

China's government plans 1 trillion yuan ($146 billion) of spending to build waste water-treatment plants in the five years through 2010, the Ministry of Construction said in August. As many as 278 cities lack proper treatment facilities, it said.

link

Water. It's quite important to the human body. Arabs are going to be in serious trouble if they don't invest in solar power soon. In any case, if you had the choice to die of Peak Oil related causes, would you rather starve to death or die of a lack of water? Best thing to do is to get a bottle of ethanol first, to get drunk, so you can die in delirium.

[smallpoxgirl]

Water. It's quite important to the human body. Arabs are going to be in serious trouble if they don't invest in solar power soon.

I can't imagine why they aren't using a solar process to desalinate the water in the first place. Why not just paint a pool black. Put a clear cover over it. Fill it with seawater. Run cool seawater through some pipes near the cover and collect the condensate from the outside of the pipes. Viola...solar distillation. Ultra low tech, and requires minimal energy input.

[Tanada]

I can't imagine why they aren't using a solar process to desalinate the water in the first place. Why not just paint a pool black. Put a clear cover over it. Fill it with seawater. Run cool seawater through some pipes near the cover and collect the condensate from the outside of the pipes. Viola...solar distillation. Ultra low tech, and requires minimal energy input.

Mostly its a case of volume, with a semi-passive solar design like you propose the throughput of fresh water is pretty small. To figure it out you need to know two things, your local pan evaporation rate and the area of your pool. In my area that averages around 1000mm/y or 2.75mm/day. If your proposed pool is 3 meters in diameter your area is just over 7 meters square. (7*2.75)*100=1,925 mL or just under two liters of distilled water unless I screwed up my math somewhere, which is ALWAYS possible. Meanwhile if you use a windmill powered pump and a simple water tower/reverse osmosis system you could get that much out of seawater every minute or so the wind blows.

The big Fusion reactor in the center of the solar system will outlast all of us, but the energy we get from it is very diffuse indeed.

[kublikhan]

a few million gallons a day is not going to change the face of the mideast either. Natural evaporation takes place over the entire surface of the ocean. Desalination takes the brine and concentrates it one place. Not a problem for one plant. As a solution to third world water shortage? I have my doubts.

I also have doubts as to how eco-friendly this technology will be if deployed on a large scale. It is not just the brine discharge that is a problem. The intake is a problem as well. You are sucking in not just salty water, but marine organisms as well. Typically these organisms end up dead by the time they are finally discharged from the RO plant. Then their is the discharge. The salt concentration doubles from 35,000 ppm in the water intake to 70,000 ppm in the brine discharge. And you are not just concentrating salt, you are concentrating chemicals and pollutants as well. There are approaches you can take to minimize the ecological impact of both the intake and discharge(sandy soil pre-filtration, large area diffusers, etc.), but these are not always applicable in all areas.
Desalination

[Tanada]

a few million gallons a day is not going to change the face of the mideast either. Natural evaporation takes place over the entire surface of the ocean. Desalination takes the brine and concentrates it one place. Not a problem for one plant. As a solution to third world water shortage? I have my doubts.

I also have doubts as to how eco-friendly this technology will be if deployed on a large scale. It is not just the brine discharge that is a problem. The intake is a problem as well. You are sucking in not just salty water, but marine organisms as well. Typically these organisms end up dead by the time they are finally discharged from the RO plant. Then their is the discharge. The salt concentration doubles from 35,000 ppm in the water intake to 70,000 ppm in the brine discharge. And you are not just concentrating salt, you are concentrating chemicals and pollutants as well. There are approaches you can take to minimize the ecological impact of both the intake and discharge(sandy soil pre-filtration, large area diffusers, etc.), but these are not always applicable in all areas.

As you said yourself a very low tech sand prefilter takes care of the macrobiotic intake problem. As for the rejected stream with its high concentrations of salts and contaminants, install a bleeping long plastic pipe that leads to the edge of the continental shelf before the water is released. The discharge water is higher density, therefor once off the edge of the shelf it will sink to the bottom where it will eventually mix with the cold bottom water just like the natural saline discharge from the Med basin does in the Atlantic today. Adding an oxygenation step before it enters the discharge pipe would also help buffer any bottom dwellers it encounters on the abyssal plain. Additionally if you put a longer pipe together actually going down the slope of the continental shelf for a few hundred feet with a water turbine on the bottom end you would be able to generate a healthy electric current to use to help offset the energy expense of the plant. The saline discharge water has more mass than average sea water so it will sink under gravity and provide its own 'head' pressure that could be harnessed for energy recovery.

[kiwichick]

why not create zero emission baseload power and desalinate water at the same time ?

wwwceto.com.au

[TheAntiDoomer]

Revelant to oil, in that a cheap desalination method powered by the sun would make sense for Middle Eastern countries and possibly California (using solar rather than oil to desalinate water)

http://news.slashdot.org/story/09/10/31 ... salination

THERE is a lot of water on Earth, but more than 97% of it is salty and over half of the remainder is frozen at the poles or in glaciers. Meanwhile, around a fifth of the world’s population suffers from a shortage of drinking water and that fraction is expected to grow. One answer is desalination—but it is an expensive answer because it requires a lot of energy. Now, though, a pair of Canadian engineers have come up with an ingenious way of using the heat of the sun to drive the process. Such heat, in many places that have a shortage of fresh water, is one thing that is in abundant supply.

[crude_intentions]

As a groundbreaking idea, this is right up there with hand washing or dodge ball

No this is more innovative than that if it works the way they say it does. The average human uses around 500 litres of fresh water a day (Bathing, clothes washing, drinking, toliet flush, ect). A large size Window AC unit uses around 1.5KWh. So on "Paper" it potentially breaks down that for the same amount of energy used to cool a house for an hour this process could provide a familty of three with drinking water for a day. Of course as anyone who works in the technology field will tell you "Everything works on paper"

Even the best reverse-osmosis plants require 3.7 kilowatt hours (kWh) of energy to produce 1,000 litres of drinking water.Mr Sparrow and Mr Zoshi, by contrast, reckon they can produce that much fresh water with less than 1 kWh of electricity, and no other paid-for source of power is needed. Their process is fuelled by concentration gradients of salinity between different vessels of brine. These different salinities are brought about by evaporation.

the low pressure of the pumps needed (in contradistinction to those employed in reverse osmosis) means the brine can be transported through plastic pipes rather than steel ones. Since brine is corrosive to steel, that is another advantage of Mr Sparrow’s and Mr Zoshi’s technology.

[Graeme]

New Microfluidic Device Can Remove Salt from Seawater

Scientists from the Massachusetts Institute of Technology (MIT), in Cambridge, have recently announced the development of a new type of microfluidic device that is capable of extracting the salt out of sea water. The innovation allows for scientists to produce about one glass of water each hour, using only about the same amount of energy as a table lamp. The main advantage that the new technology, called ion channel polarization, has over the regularly-used reverse osmosis process is that it is portable, as it relies on components that operate at a very small scale, ScienceNow reports.

softpedia

[timmac]

Thanks for that post, I always thought some day some scientist some where was going to invent a much cheaper and easier way to make fresh water form sea water, once this is more perfected and can make large amounts faster it will replace fresh water shortages around the world.

Same goes with auto's, oil shortages will not kill auto's, man will not go backwards with transportation, we will find other ways to fuel our auto's..

[Outcast_Searcher]

This is interesting. There have been various methods, including some similar to this for making brackish water (salty, but to a much lesser extent than seawater - there are lots of brackish aquifers in the US, for example) drinkable.

But doing this with seawater raises the potential to a whole new level.

[Keith_McClary]

Assuming a 100 Watt lamp and a .25 litre glass, the efficiency is

0.1 kWh / .00025 m3 = 400 kWh/m3

compared to 2 kWh/m3 for reverse osmosis.

Energy Efficiency in Reverse Osmosis Systems

[rangerone314]

Too bad they can't use salt water as a coolant in solar panels and then collect the evaporated water and salt residue left over.

[Carlhole]

New Scientist

Today's desalination plants are unlikely to solve our looming water crisis, however. That's because they have their own unquenchable thirst- for energy. It's needed to drive reverse osmosis (RO), the process in which salty water is forced at high pressure through a membrane that lets water molecules through but blocks the salt. But now a number of researchers and start-up companies think they have a more energy-efficient alternative, and it works by turning RO desalination on its head.

So instead of fighting this energy gradient, why not try to harness it? That's the thinking behind the experimental "forward osmosis" plants that are starting to appear. Water can be sucked effortlessly out of seawater if you offer it a more concentrated "draw solution" to flow into. At first sight that might not appear to achieve anything, but if you are clever about what you use in the draw solution, you can get pure water out at the end.

The team says its method could produce fresh water while using only 20 per cent of the energy of today's desalination plants.

[Ludi]

The recipe for fresh water: Restore the watersheds.

http://www.harvestingrainwater.com/

[Tanada]

Given the steep declines now taking place in the Ogalala Fresh Water Aquifer what we really need is cheap desalination of deep saline water to keep up irrigation rates. This will be even more important if Climate change shifts rain away from the North American cereal belt.

[C8]

Chemists Work to Desalinate the Ocean for Drinking Water, One Nanoliter at a Time

June 27, 2013 — By creating a small electrical field that removes salts from seawater, chemists at The University of Texas at Austin and the University of Marburg in Germany have introduced a new method for the desalination of seawater that consumes less energy and is dramatically simpler than conventional techniques. The new method requires so little energy that it can run on a store-bought battery.

The process evades the problems confronting current desalination methods by eliminating the need for a membrane and by separating salt from water at a microscale.

To achieve desalination, the researchers apply a small voltage (3.0 volts) to a plastic chip filled with seawater. The chip contains a microchannel with two branches. At the junction of the channel an embedded electrode neutralizes some of the chloride ions in seawater to create an "ion depletion zone" that increases the local electric field compared with the rest of the channel. This change in the electric field is sufficient to redirect salts into one branch, allowing desalinated water to pass through the other branch.

"The neutralization reaction occurring at the electrode is key to removing the salts in seawater," said Kyle Knust, a graduate student in Crooks' lab and first author on the paper.
Like a troll at the foot of the bridge, the ion depletion zone prevents salt from passing through, resulting in the production of freshwater.

Thus far Crooks and his colleagues have achieved 25 percent desalination. Although drinking water requires 99 percent desalination, they are confident that goal can be achieved.

"This was a proof of principle," said Knust. "We've made comparable performance improvements while developing other applications based on the formation of an ion depletion zone. That suggests that 99 percent desalination is not beyond our reach."

The other major challenge is to scale up the process. Right now the microchannels, about the size of a human hair, produce about 40 nanoliters of desalted water per minute. To make this technique practical for individual or communal use, a device would have to produce liters of water per day. The authors are confident that this can be achieved as well.

Clever humans! This many help communities with low water availability. Desalinated water may be pumped to Phoenix from the Pacific for instance (maybe Kunstler was wrong about that city "blowing away). Seawater intrusion of aquifers will also cause problems- this might help. Desalinated water is also very useful in energy production.

Full story below:

http://www.sciencedaily.com/releases/20 ... 125525.htm