Alaska To Export Billions of Gallons of Water 290
theodp writes "Newsweek reports on a company called True Alaska Bottling that has purchased the rights to transfer 3 billion gallons of water a year from Sitka, Alaska's bountiful reserves. If all goes according to plan, 80 million gallons of Blue Lake water will soon be siphoned into the kind of tankers normally reserved for oil and shipped to a bulk bottling facility near Mumbai. From there it will be dispersed among several drought-plagued cities throughout the Middle East. Think of it as a proof of concept for turning life's most essential molecule into a global commodity." I'm sure the residents of Saratoga Springs and Perrier (not to mention the island nation of Fiji) can think of some prior art.
Re:or desalinate? (Score:5, Informative)
Not as much as you'd think (Score:5, Informative)
Those big engines in ships are the most efficient machines humans have ever built in terms of work done for energy input. They also don't have to work all that hard to move the ship. Inertia goes a long way, you get a ship moving it doesn't require an overwhelming amount of energy to keep it moving. As such shipping goods is pretty cheap. Not free, of course, but not near as much as you might think. You get used to the rates it costs to move somethign by truck or plane because that is the kind of thing you deal with when shipping small goods domestically. That is not at all related to the costs of shipping something on a large cargo ship.
For that matter if oil becomes problematic, the ships can simply be run on nuclear. The US Navy already does this with many ships. It might not be practical to stuff a nuclear plant in a car (I doubt it is even possible to make a working one of that scale) but they easily fit on a ship.
Re:or desalinate? (Score:3, Informative)
Re:or desalinate? (Score:5, Informative)
You get a lot of desalinated water in resorts in the med. You can always tell because you can taste the salt in it - and they told us the water purified for touriests was purified 10 times more than the water for the locals. I think getting it down to the point where you cannot taste it is prohibitively expensive with today technology. So I can see why they would want a whole supertanker full of fresh Alaskan water. Of course it might taste a bit oily...
Re:Not as much as you'd think (Score:3, Informative)
Re:Not as much as you'd think (Score:4, Informative)
To get electricity to those electric motors, you have to have a mechanical device, like this engine, driving a generator somewhere. So the whole system is lower efficiency. Remember that these motors drive the shaft directly. Their mechanical output goes off to assembly that drives the propeller. Means the over all system efficiency is high, so long as their efficiency is high.
In an electric drive system, like say a diesel train, you get less overall efficiency. The engine drives a generator, which then powers motors. Though the electric motors themselves are quite efficient, when you add in the transmission and generation, the system falls below what you'd get if you just drove them directly. In the case of a train you don't because you'd need a gear box of amazing proportions and still might not get enough torque at the low end. However that is not a problem in a ship.
The fact remains that those big engines are basically as efficient as it gets per energy input, and a ship pretty directly transfers that energy to the propeller with not a whole lot of mechanical loss. Hard to find a more efficient system over all.
You cannot take one component of a system and crow on about how efficient it is, that doesn't matter in terms of fuel cost. Fuel cost comes down to the efficiency of the whole system. You compare the energy, in the form of your fuel, that goes in to the work that comes out.
Re:Not as much as you'd think (Score:3, Informative)
That would be great if you had a 100% efficient way of creating electricity. Coal still creates around 50% of the power in the USA and is only around 40% efficient. And you've got to factor in transmission losses from the power plant to your 100% efficient electric motor.
Re:Huh, wut? WTF it's raining anyway.... (Score:3, Informative)
I've heard of standard modal containers outfitted with plastic insets - sounds reasonable as the infrastructure to move them is well developed - but I've yet to see one.
'Containers' that consist of a cylindrical steel tank with a container-shaped frame around them are common enough. Plastic insets are also available from e.g. SAI [saifreight.com].
That would leave you with 25-ton units which have to be unloaded one at a time, but would fit in standardized distribution channels. A tanker would be cheaper and faster to load and unload, but requires dedicated infrastructure.
Re:or desalinate? (Score:5, Informative)
Re:We've got water problems in the lower 48 (Score:3, Informative)
That's kind of the point. The Great Lakes are a huge, easily-tapped resource, and that resource is renewable (in principle), but it's still finite. That's why those of us in the GL basin with our heads on straight don't want to build a pipeline to the southwest (or anywhere else), no matter how much they offer to pay.
Re:We've got water problems in the lower 48 (Score:3, Informative)
Re:News For Nerds (Score:5, Informative)
They probably wouldn't use crude oil carriers, more likely product carriers which usually carry stuff like gasoline or gasoil. These products are much easier to clean than crude oil, a high pressure fresh water/detergent mixture would probably do the trick. A couple more fresh water rinses would get all the detergent out.
Lining the tanks with rubber isn't feasible. Tankers have on-board cargo pumps located just above the keel (the lowest possible location). Cargo pumps have to be at this level to be effective, otherwise you'd never get a high enough pressure at the pump inlet, causing all sorts of problems such as cavitation [wikipedia.org]. For more information, check out Wikipedia's page on Net Positive Suction Head [wikipedia.org].
Lining the tanks with rubber would block the pipes going to the cargo pumps, and since you can't use shore-based pumps to unload the cargo, there'd be no way to unload except with a pump lowered into the tank through one of the manholes. That would only allow for very small pumps to be used (they'd have to fit through a manhole), meaning it would take weeks or months to fully unload the ship.
Re:or desalinate? (Score:5, Informative)
Your math seems solid, but taking the Emma Maersk as an example doesn't quite work.
Container ships carry time-critical goods, meaning they have to be fast. The Emma Maersk [wikipedia.org] is among the fastest cargo ships in the world, doing 25.5 knots. Tankers sail much slower, for example the Hellespont Alhambra [wartsila.com] does 16.5 knots, which is quite fast for a tanker. Lower speed means you need less engine power, which means you consume less fuel. While the Emma Maersk has an 80MW main engine and five auxiliary engines of 6MW each (totaling 110MW), the Hellespont Alhambra makes do with a main engine of 36.9MW along with three auxiliary engines generating 1.5MW each (totaling around 41.5MW).
Another difference is that containers have a very low density, meaning container ships have a relatively low deadweight tonnage (carrying capacity). The Emma Maersk can carry 156,907 tonnes, the Hellespont Alhambra can carry 442,470 tonnes.
This means the Hellespont Alhambra carries 2.82 times the amount of cargo, using only 37.7% of the Emma Maersk's fuel while running at 64.7% of the Emma's speed. This means it is (2.82*0.647/0.377) 4.84 times as efficient as the Emma Maersk.
Napkin math aside, they'd use smaller tankers for this, since Alaska doesn't have any ports that can accommodate supertankers with their 24m (80ft) draft.