Backroom lab boys in the US Navy say they have developed hugely more efficient desalination machinery, ideal for making seawater drinkable. The new tech, as well as saving space and energy aboard US warships, could also bring relief to water-poor areas around the world.
"They say that water is the next petroleum," comments J Paul Armistead of the US Office of Naval Research (ONR). "Around the globe there are a lot of countries with a lot of worse water problems than we have, so bringing down the cost to desalinate water should help a lot."
At present, modern warships replenish their freshwater supplies from the sea around them using basic Reverse Osmosis (RO) plants. There are also already some nations in part dependent on desalinisation to keep their onshore water systems running, such as Israel and the United Arab Emirates, though distillation has been more common than RO in shorebased installations. A large RO plant is even being built in London's Thames estuary to provide backup supplies for the capital in case of dry summers - despite initial opposition from former Mayor Ken Livingstone on the grounds that it would be irresponsible to use energy (and so drive up carbon emissions) for such a purpose.
Freshwater scarcity is a much more serious problem in many regions around the globe than it is in London, and where there is easy access to seawater desalinisation could offer a solution for routine use, not just emergencies. However, this involves the use of a lot of energy. Even aboard warships, the RO plants seldom offer enough output for sailors to use water as profligately as Western civilians do.
Step forward Armistead and the assembled boffins of the ONR, with their Expeditionary Unit Water Purification Program, EUWP. This has been running since 2004, and the navy lab is now on the second generation of kit.
"We plan to build prototype desalination units that will use 65 percent less energy and be 40 percent smaller by weight and by volume relative to current Navy reverse osmosis systems," says Armistead. "They should require roughly 75 percent less maintenance."
According to the ONR, a Gen I EUWP rig was set up in Mississippi and used to supply potable water to a hospital whose supplies had been cut off by Hurricane Katrina in 2005. Sucking saltwater from the Gulf of Mexico, the truck-portable unit pumped out 100,000 gallons of drinking water per day - the equivalent of a 24-hourly convoy of 18 road tankers. The Gen II gear, which has now been successfully tested, is supposed to be more puissant still.
The US navy's ships will start getting the new and enhanced water plants from 2014: and Armistead says that EUWP tech has already begun to spin out into civilian commercial applications. It would seem that the human race has no particular need to suffer from drought in future (at least that substantial majority of the human race which lives within reasonable reach of saltwater). Assuming that the human race has access to plentiful energy for running the desalination plants, anyway.
There's no such thing as a water shortage in particular, it would seem - just situations in which energy shortages can be even more damaging than you'd expect. But at least the new ONR kit will somewhat ease the growth of humanity's energy needs. ®