Dunno. Maybe a few hours of a tug boat is less energy than desalinization of a similar amount of salt water? Not to mention desalinization plants likely cost more than a tug boat.
Doubly so if you need to ship fuel to the desalinization plant via boat.
I'm guessing a water pipeline would be cheaper, and it would need less capacity. But it would have to be constructed for underwater conditions, and any maintenance would be cumbersome.
The Langeled underwater pipeline, carrying natural gas from Norway to the UK, is a bit longer than the Barbados-Surinam distance (at 1200 km), and cost approx. 2 billion USD adjusted for inflation. That's a really big-ass pipeline though, at 44" diameter. I guesstimate they could probably get this water pipeline done at about a hundred million USD.
Edit: Digging a bit further, subsea pipeline lay cost can be roughly approximated at 0.04 million USD per inch-kilometer (that is, multiplied by pipeline length and by diameter in inches) for 8"-24" pipe. Furthermore we can estimate that Barbados would need a flowrate of 5 000 L/s to supplement their water supply, giving an optimal pipeline diameter of 8". That means it would cost 942km * 8in * 0.04 million USD/(km*in) = 300 million USD.
Actually, work does scale with the diameter. For lower diameter pipe, you can use a smaller, less specialized lay barge with less crew, the welding goes quicker meaning progress is faster, and you can fit more km of pipe on each supply ship.
Also, the cost of permits (called Right-Of-Way, ROW) is a very small fraction of the total cost, as is the planning cost. Materials cost for the pipe, OTOH, can be as much as 60% of total.
Pipelines for water are only energy efficient if you have gravity working for you. I'm willing to wager that there isn't a 10x difference in the cost of towing that water to the Barbados versus pumping it in a pipeline. And, of course, you don't need a pipeline when you tow it. (though you do need big bags)
I always wonder about ideas like this. Desalination is a known solution and big boats full of fuel that can power desalination plants are a solved problem. In terms of under utilized infrastructure you could put tanks in shipping containers and use unused container craft to move the water from port to port. Hanjin has a bunch available for cheap at the moment.
You need the destination to have a suitable container port, and a way of emptying a large number of containers into the water system quickly. If you want to use normal shipping it would probably be eaiser to just import and distribute bottled water.
A big bag would just need a pipeline to come ashore and could be more easily pumped than hundreds of shpping containers. Although the details of their plan seem sparse. Does the bag offload into a water mains system, and will it need treatment before use?
With climate change Caribbean islands would eventually have to invest more into desalination plants. Some already have these plants but they are small scale and used to augment main sources of fresh water.
All drinking water from the tap in Curacao has been from a huge desalination plant for many years, see also [1].
There's a shortage of water alright, but not drinking water.
I don't know anything about this story, but when I just asked a friend who lives down there it was not known to him.
When I showed him the article he said that it reads more like a first of April joke as anything serious.
For the record, it does not happen much, but it has been raining down there now for 2 whole days.
If people are willing to pay as much for water as they do for oil or gas, can we use oil infrastructure (tankers, pipelines, trains, etc) to transport water?
Can we assume they'd be willing? Here in Canada I use orders of magnitude more water than oil products, and would be willing to pay commensurately less.
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[ 2.1 ms ] story [ 66.9 ms ] threadDoubly so if you need to ship fuel to the desalinization plant via boat.
One would think a pipeline would be cheaper. I guess they have done the maths on a $2 million investment though. But it's not intuitive.
I'm guessing a water pipeline would be cheaper, and it would need less capacity. But it would have to be constructed for underwater conditions, and any maintenance would be cumbersome.
Edit: Digging a bit further, subsea pipeline lay cost can be roughly approximated at 0.04 million USD per inch-kilometer (that is, multiplied by pipeline length and by diameter in inches) for 8"-24" pipe. Furthermore we can estimate that Barbados would need a flowrate of 5 000 L/s to supplement their water supply, giving an optimal pipeline diameter of 8". That means it would cost 942km * 8in * 0.04 million USD/(km*in) = 300 million USD.
Also, the cost of permits (called Right-Of-Way, ROW) is a very small fraction of the total cost, as is the planning cost. Materials cost for the pipe, OTOH, can be as much as 60% of total.
Still I think the numbers seem off for a boat dragging water in bags for 6 days to be cost effective.
A big bag would just need a pipeline to come ashore and could be more easily pumped than hundreds of shpping containers. Although the details of their plan seem sparse. Does the bag offload into a water mains system, and will it need treatment before use?
I don't know anything about this story, but when I just asked a friend who lives down there it was not known to him. When I showed him the article he said that it reads more like a first of April joke as anything serious.
For the record, it does not happen much, but it has been raining down there now for 2 whole days.
[1] https://www.theguardian.com/sustainable-business/2015/feb/18...
I hope this is something that's only reserved for emergencies, and is otherwise unprofitable.
I get the feeling that this could become horribly destructive behavior, if it catches on as a global trend.
Meanwhile, quotes such as these are disturbing to read:
Actually, in terms of things human activity can place stress upon, and ultimately ruin, few things are "nearly unlimited."Pretty soon we'll be towing icebergs & what an amazing day that will be.
It was a huge industry in the northeast in the 17th(? I think) century. Got this info from an awesome documentary called the Science of Cold.
Looks like water costs $2 / cubic meter, and oil costs 100x more than that, so we have a long way to go before this makes any sense.