UAE To Drag Iceberg From Antarctica To Solve Water Shortage Set To Last 25 Years (express.co.uk)

schwit1 quotes a report from Daily Express: The UAE, which is among the top 10 water-scarce countries in the world, hopes to help ease the stress of a drinking water shortage by towing an iceberg from the freezing Antarctica in order to create more drinking water. The National Advisor Bureau Limited's (NABL) managing Director Abdullah Mohammad Sulaiman Al Shehi says an average iceberg contains "more than 20 billion gallons of water" which would be enough for one million people over five years. Up to four-fifths of an iceberg's mass is underwater, and due to their vast density, they would theoretically not melt in the boiling climate of the Middle Eastern coastal line. Mr Al Shehi says it could take up to a year to drag the huge body of ice up to the UAE, and the project is set to begin in 2018.

Comments

Dense

[nastyphil]

".. and due to their vast density, they..."

Uhhhh, Icebergs are *less* dense that's why they float. I think the author means mass.

Two Words

[Dracos]

Desalinization plant.

Re:Two Words

[Sarten-X]

I did some math. Previously, I've considered similar absurd ideas, and the cost just didn't fall in their favor.

I feel I should start with a disclaimer: It's currently a very late (or early, depending on one's perspective) hour of the evening, and my physics skill isn't what it used to be. I invite and encourage you all to review my work, and if I'm wrong, please tell me how.

Based on the figures provided, we can work out the magnitude of the problem. The first computation is simple: Our speed will be .3m/s, to travel the (roughly) 10000 kilometers between Antarctica and the UAE in one year.

20 billion gallons of water corresponds to roughly 80 million cubic meters of ice. Cut into a sphere for ease of transport and calculation, it would have a radius of about 300 meters, with a cross-sectional area of about 200,000 square meters. We'll ignore the air resistance of the 10% above water, which falls within the error of my rough calculations. Calculation for the force of drag is ugly*, but works out roughly to C*9*10^6 newtons. That "C" is a coefficient simplifying the effect of the iceberg's shape, ranging from 0.5 for a sphere to 2 for more troublesome shapes.

Considering that range, the water's drag is between 4 and 20 meganewtons. A power source (tugboat, added motors, etc) will need to supply that much force just to maintain speed. If I remember my physics correctly, at 0.3m/s, that's between 2000 and 7000 horsepower.

There are tugboats with that much power. I haven't found much information on the annual cost to operate such a beast, but one tugboat operator gives price estimates per hour. For the purposes of this discussion, we can assume that the quoted price covers the operator's expenses well enough to also cover the overhead of running such a large operation, and the benefits of scale will cover the higher costs of an ocean-going expedition. Those are some very large assumptions, but I don't have information to clarify it further.

With those assumptions, the cost to pull an iceberg for a year is only about $20 to $100 million. That's surprisingly cheap, putting the cost of mostly-fresh water at under $0.001 per liter ($0.005 per gallon). In comparison, a desalination plant supplies water at about $0.0005 to $0.003 per liter ($0.001 to $0.01 per gallon).

In short, it's expensive, but it's in the same ballpark as regular desalination for that much water, and if the losses due to melting and evaporation can be controlled, it might just be feasible. As noted in TFA and elsewhere, it would also be quite the spectacle, promoting yet more tourism to the area.

* The formula I ended up with is F[drag] = C*.5*1g/cm^3*(.9*pi*(80000000 m^3/(4*pi/3))^(2/3))*(0.3m/s)^2.

Re:Two Words

[Solandri]

You forgot to subtract the fraction of ice which would melt during that 1 year journey.

And we're doing desalination plants wrong. Right now they're usually reverse osmosis using electric pumps to generate the pressure needed force water through the filters. This is because the electric cost of reverse osmosis is less than the electric + heating cost of distillation. Water has a very high specific heat, so it takes a lot of energy to evaporate it.

We need to be adding desalination to power plants. Nuclear and fossil fuel power plants generate heat as a waste product. They get rid of it by heating up seawater or river water, or by evaporating water in big cooling towers. Instead of throwing that heat away, using it to distill seawater ends up being cheaper than reverse osmosis.

Re: Two Words

[careysub]

I just did some googling, looking for more information about their plans and found this which is quite interesting. It puts the plan in a somewhat different light, and answers many of comments made here.

A key reason for this iceberg towing plan is specifically local environment modification. All those desalinization plants are pumping bring into the coastal waters, and the icebergs are going to be allowed to melt in open water to counteract the increased salinity and restoring the ecological balance in those coastal waters. And through feedback effects they anticipate that is will modify the local climate, creating a cool air layer (basically an artificial inversion effect) and increasing rainfall.

Vast Density

[chuckugly]

Vast density is what the guy who wrote that craptastic article has.

Wouldn't just buying water from other countries be

[TheOuterLinux]

Or, are we trying to solve the polar ice melting by drinking it? Get rid of the evidence! Flushing ice cubes down the toilet.

Iceberg huh?

[mentil]

The water shortage is expected to last 25 years, and the average iceberg contains enough water for 5 years (for 1 million people). According to Google, the UAE population is currently ~9.16Million, meaning if all of the water were recovered, it would last about half a year if all water came from the iceberg. And they're planning on starting this project next year. They'd have to tow two average icebergs a year to supply everyone from it. Ok, maybe only like 10% of water will come from the iceberg, but it has to go through a water-treatment plant before it'll be used, presumably displacing capacity for processing other water that'd be run through it instead.

Source looks like a tabloid, by the way.

Re:Iceberg huh?

[Harold Halloway]

I wonder why the water shortage is expected to last 25 years? What is going to happen in 25 years to ameliorate this problem?

Re:Iceberg huh?

[Anonymous Coward]

There is more detailed info here:

http://www.independent.co.uk/news/world/middle-east/uae-icebergs-drinking-water-from-antarctica-towed-united-arab-emirates-a7715561.html

They plan to tow multiple icebergs over the course of time and state that icebergs have microclimate effects, including increasing rainfall. As to how they will extract the water:

"Blocks will be chipped off the iceberg above the waterline and then crushed into water, before being stored in large tanks and filtered through a water processing plant."

Not the first time

[AutodidactLabrat]

Australia proposed exactly this suggestion about 25 years ago.
Then they started looking for ships powerful enough to move such a drag
Project died.
Surprise.

Re:WTF IS UAE???

[Anonymous Coward]

Sorry, but what do you mean by 'WTF'?

Why 25 years?

[mentil]

a ) Emergence of New Tech(tm) to solve the problem!
b) The managing director expects to tire of playing golf in the desert within 25 years, and will reluctantly relinquish the water.
c) After 20 years of delays in the construction of desalination plants due to graft, the corrupt ministers will retire, thus leaving only a new generation of completely honest ministers, and the plants will be finished up within 5 years.
d) Everyone will have left the UAE due to other countries moving away from ICEs, regional strife, etc.
e) Mandatory 25-year water shortage. Sorry, they'd LOVE to fit it into their schedule next century, but darn, it's just too FULL.
f) Aliens. Somehow.
g) The Rapture will happen in 25 years so it'll be moot.

Re:Drinking water?

[Deadstick]

No. Only a small part of an iceberg is generated by freezing of seawater; most of the water arrives in the form of snow. Even the freezing of seawater is a natural salt-removal process involving the behavior of crystal lattices.

Re:Drinking water?

[hey!]

Nope. You're thinking of sea ice, which forms in salt water. Icebergs are formed by glacial calving or ice sheets that originate on land.

But even sea ice is less saline than seawater, because the freezing process expels brine. But because sea ice is flat like a pancake it has a larger surface area to volume ratio.

Re:Salvage I Reboot?

[quantumghost]

It was one of the ideas pitched to Montgomery Brewster (Richard Pryor) in the movie Brewster's Millions, execpt the guy wanted to tow it from the Arctic.