
China Turns to the Sea for Fresh Water - Sami_Lehtinen
http://www.bloomberg.com/news/articles/2015-04-09/china-embraces-desalination-to-ease-water-shortages
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jarito
Why not look at something like nuclear? Since the need is both electricity and
heat, a nuclear reactor seems ideal since you don't have to convert power back
in to heat - you can just use it directly.

With modern recycling techniques and reactor designs the chance of meltdown
and wastes are limited, but that seems better than more coal.

Not an expert on reactor design vs desal design by any means - would love an
opinion on the challenges here outside the standard nuclear ones.

~~~
allendoerfer
Many places with water shortage are sunny and hot. In my mind it is the
perfect use case for solar thermal power plants. I just love how simple they
are. If we build coal or nuclear power plants, we just ditch one problem for
another.

It is also a great way to smoothen the varying production of renewal energy.

~~~
jarito
That's an interesting idea as well. A molten salt reactor or something similar
would have the same benefits as nuclear, you just trade reliability for
cleanliness. I would imagine that a molten salt set up would be significantly
cheaper to build as well, but I could be wrong on that.

~~~
spiritplumber
A good thing is that you don't care about normalizing usage: if the plant
happens to only work during the day, it's fine, you can make fresh water
during the day and use your storage tanks at night. Unlike with batteries,
there's basically no waste in storing water overnight.

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lnlyplnt
Israel (obv a different scale than china) has recently also experienced a big
push toward desal. What's interesting is there's a moore's law type of effect
at play here, desal keeps getting cheaper and cheaper to the point where it's
actually a practical alternative to ground water, filtering etc.

I think water will be another great Malthusian disappointment, ocean water is
basically unlimited (correct me if I'm mistaken), and on a 20-50 year time
horizon it seems that the world should be able to alleviate all water scarcity
by tapping it.

~~~
kiba
What will you do with the salts and various impurities?

~~~
derekp7
Dump it on the roads in the North during the winter.

Or, more seriously, if it is salt that was extracted from the sea, there
shouldn't be much harm in putting it back. The fresh water that was extracted
will end up back in the sea also, so overall there should be no increase in
salinity (except locally where the salt is dumped).

~~~
azinman2
Why can't we just eat the salt?

~~~
maxerickson
A liter of seawater has 35 grams of salts in it (I looked it up:
[http://en.wikipedia.org/wiki/Seawater](http://en.wikipedia.org/wiki/Seawater)
). Compare that to the recommended daily intake of several grams of salt.

It's also the case that most of the desalination methods produce concentrated
brine instead of dry, clean salt (so extracting the salt would require further
energy), but not needing that much of it is the bigger reason.

~~~
azinman2
I didn't mean to drink it, I meant to turn it into table salt.

Seems like there ought to be some kind of further usage of it.. industrial or
otherwise.

~~~
maxerickson
I got that. For every liter of seawater that is desalinated, there would be
~35 grams of table salt. On a given day a person might use 4 grams of salt.

Given typical water usage, you quickly have salt for an awful lot of people
(salt for hundreds of people per person consuming the water).

I guess other users would be welcome, even if they just take it for free that
probably saves the desal plant on disposal costs.

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adinb
How crazy would it be to (Mostly to help the American Southwest, though if it
worked, it could be used anywhere that uses river basins as a major source of
freshwater for extremely large areas) create a large pipeline to feed an
inland desal plant that's located along the shortest, lowest, least populated
path to the headwaters of multiple major freshwater sources, like the Colorado
and Rio Grande and the pump desal water into the existing water distribution
network?

While it's a major geoengineering project (musk-scale!), it would allow for
usage of current legal and physical water distribution to be reused.

Also, while CA desal cites briny outflow disposal as a major impediment to
desal, why not pump the outflow to existing salt flats?

(Edited for clarity)

------
pmorici
Maybe they can export their excess freshwater in giant tankers to CA to solve
their drought problem. They already produce most of the electronics we
consume.

~~~
dalke
If that were reasonable then we would tank water in from Alaska. Or China
would buy AK water.

If you want to dream big, in the 1980s there were pipe dreams of bringing in
water from the Copper or the Stikine through a large off-shore pipeline to
California.

~~~
maxerickson
There have been serious proposals to ship Great Lakes water to Asia. This
article mentions one:

[http://www.wbez.org/frontandcenter/2011-06-21/great-lakes-
fa...](http://www.wbez.org/frontandcenter/2011-06-21/great-lakes-face-
increasing-pressure-water-world-own-backyard-88159)

There is now an agreement placing tight limits on what happens to the water:

[http://en.wikipedia.org/wiki/Great_Lakes%E2%80%93Saint_Lawre...](http://en.wikipedia.org/wiki/Great_Lakes%E2%80%93Saint_Lawrence_River_Basin_Sustainable_Water_Resources_Agreement)

~~~
dalke
There's serious and then there's serious.

Fiji exports water to the US. I've heard of a bagel company in London which
imports its water from New York City. People buy ice that comes from Alaskan
glaciers. (Minor note: If you use under 20 tons/year of tidewater glacier ice
then you don't need a permit.) So people are willing to pay a lot of money for
provenance.

Fiji Water is a good comparison. According to its Wikipedia page, it was
exporting over 15 million liters/month. According to others, it was a least
3.5 million liters per month. According to
[http://www.alternet.org/story/101207/the_true_price_of_fiji_...](http://www.alternet.org/story/101207/the_true_price_of_fiji_water)
it was 130 million liters in a year. I'll say it was 5 million L/month or 60
million L/year.

According to the Wikipedia page for "Water export", the Great Lakes -> Asia
deal was for 600 million liters, or about 10x of what a single well in Fiji
can provide.

Oil shipping costs something like $1.20/barrel from Qatar to Rotterdam, says
[https://books.google.com/books?id=cUHAAgAAQBAJ&pg=PA232&lpg=...](https://books.google.com/books?id=cUHAAgAAQBAJ&pg=PA232&lpg=PA232&dq=supertanker+cost+per+barrel&source=bl&ots=wujrW689cS&sig=XSED9PyMmfzcxmwxP0JKv3g-xWw&hl=sv&sa=X&ei=C7UqVeWCFoLmyQPvxoCQAg&ved=0CB8Q6AEwADgK#v=onepage&q=supertanker%20cost%20per%20barrel&f=false)
. A barrel is 120 liters, or 1 cent per liter shipping costs.

That's about $12 thousand per acre-foot. The price of desal water is under
$3,000 an acre-foot.

If the goal was to market provenance - the Fiji Water of Asia - then it might
be profitable. It otherwise doesn't seem like a serious proposal.

If there were a were serious need, then I would expect to see water exports
from Alaska, which allows bulk water exports (again, according to the "Water
export" page at Wikipedia) and is a lot closer to Asia.

Since there isn't, I have difficulties understanding how there's a serious
proposal.

~~~
maxerickson
There certainly isn't a serious existing proposal, there is a series of
agreements making sure it isn't done.

I was just saying that someone had thought about doing it, enough so that they
went ahead and got a permit.

I wonder what the prices for shipping and desal were in 1997...

~~~
dalke
Oh, I agree. I was just saying that there's "serious" and there's "serious"

[http://www.greatlakeswaterwars.com/chapter11.htm](http://www.greatlakeswaterwars.com/chapter11.htm)
says that it was a for-profit "humanitarian effort on behalf of the world’s
poor that was also designed to make money".

I can't figure out how it was supposed to work. It looks like it comes down to
person who wanted to do it was in Sault Ste. Marie, Ontario, and thought of
the tons of water in the backyard [paraphrasing]. So he and his partners could
have been serious about, but there's no real chance it would work out.

It doesn't really matter what the prices were in 1997. Alaska water is closer
to Asia than the Great Lakes. If it made sense for Lake Superior, it would
make even more sense for water from the Sitka.

[http://www.heatisonline.org/contentserver/objecthandlers/ind...](http://www.heatisonline.org/contentserver/objecthandlers/index.cfm?id=3723&method=full)
says that around the same time :

> A company called Global Water Corp. has announced plans to ship up to 5
> billion gallons a year of glacier water by tanker from Alaska, near the port
> city of Sitka, to the Middle East. The company said on its Internet web site
> that it has reached agreements with buyers in China, and that it plans to
> negotiate with interested parties in the southwest U.S.

There's a lot of people who talk, in the hopes that someone else will front
the money. It's not really a con, because it might actually work. But if
things are borderline, it can help to sound serious and express no doubts.

------
Someone
_" the facility will remove salt from 120,000 tons of seawater each day. The
result will be 50,000 tons of potable water"_

Huh? What happens to the other 70,000 tons of water? Or do they mean it will
take in 120,000 tons, use something (e.g. distillation, filtering) to move
almost all the salt in it to about half of it, and get 50,000 tons of potable
water and 70,000 tons of about twice as salty as the input water?

~~~
undersuit
You are correct. The energy cost to desalinate increases as the salt content
increases, eventually you have to let it go.

------
pm90
This has been mentioned elsewhere, but I wonder if we could use the super
large tankers that are currently being built for transporting oil and gas for
transporting water instead? There is tons of fresh water in the great lakes
and the polar ice caps.

These ships don't need all the advanced machinery that they currently have for
making sure there is no leaks: if there are minor leaks, its water anyways. So
its likely to be much cheaper.

I'm concerned about the amount of fossil fuels they would consume though.

~~~
mrb
Wouldn't be worth it.

The largest super tankers have a deadweight tonnage of approximately half a
million tons, which is worth ~$500MM of crude oil.

But water is super cheap by comparison. Assuming $0.0015/L (which is what I
pay for my tap water in California), half a million tons of water is worth
only $750k.

Another way to see it: the transport cost per super tanker is about $0.02 per
gallon [1] but tap water is ~$0.006 per gallon (again, my tap water cost). So
you would be tripling its cost to transport it by sea...

[1]
[http://en.wikipedia.org/wiki/Oil_tanker](http://en.wikipedia.org/wiki/Oil_tanker)

------
msoad
California has big plans for desalination too

[http://www.mercurynews.com/science/ci_25859513/nations-
large...](http://www.mercurynews.com/science/ci_25859513/nations-largest-
ocean-desalination-plant-goes-up-near)

------
thomabs
Desalination uses TONS of electricity. Where does that electricity come from?
Fossil fuels. So this "solution" to water shortage actually increases global
warming, which will worsen water shortages. And what happens with all the
extracted salt? You guessed it - it goes right back, increasing the salinity
of the oceans.

Ah, humans.

But hey, technology solves all problems, right YC?

