Towing Icebergs to the Emirates for Drinking Water
The Middle East is home to 70% of the world’s desalinization capacity, since there are no natural water sources worth mentioning in the Gulf. A company from the United Arab Emirates has launched a plan to tow icebergs from Heard Island near Antarctica to the Gulf (Heard Island –> Fujairah, distance 8833 km/5488 miles). [Google Maps]
Is this a good idea?
In order to answer that question one has to compare the cost of desalinating a liter of water and the cost of transporting a liter of ice water from the South Pole.
Cost desalinization: 3 kWh/m3
[wikipedia.org] – Desalination
Now transport. The idea is to tow icebergs, but it needs to be realized that icebergs have 90% of their volume under water, resulting in a lot drag, drag that can be avoided by transporting the ice as water in a stream-lined oil tanker. The idea was to tow the iceberg to the Gulf (losing valuable water during the trip, due to melting) and break it up there. But if you have to break it up anyway, why not doing that at Heard Island, melt it there and transport it as water in oil tankers to the Gulf?
So what’s the cost of transporting 1 m3 of pure water per km?
[nrel.gov] – Freight Transportation Modal Shares: Scenarios for a Low-Carbon Future
On page 2: 0.5 BTU per ton-mile or 0.00023592296 kwh per ton-km.
The distance to be bridged is 8833 km, which results in 2.1 kWh/m3, ignoring the energy cost of the empty ship sailing back to Heard Island.
So according to this back-on-an-envelope calculation there is indeed some energy gains to be made by transporting rather than desalinize, but it is not spectacular (merely 2.1 over 3 kWh/m3). And there are several parameters that could tilt the balance to either of these options.
The Gulf region has abundant solar irradiation and a lot of otherwise useless desert, that can be used to build huge solar parks, delivering low cost solar energy, that be be used for desalinization.
On the other hand, the oil-tanker, or water-tanker rather, can be equipped with huge sails to save on fossil fuel.
Tentative conclusion: yes transporting ice-water from the Antarctic could compete with local desalinization of sea water, but it is difficult to identify which method will prevail in the end. Technology will decide.
[theguardian.com] – Peak salt: is the desalination dream over for the Gulf states?
[amazon.com] – Filling the Empty Quarter: Declaring a Green Jihad On the Desert
There is nothing against towing icebergs to Dubai. It is a matter of offsetting the towing costs against the cost of desalinization. The Middle East has 70% of the world’s desalinization capacity.