Green Options

In its search for more fuel efficient ways to provide drinking water for long sea voyages and remote bases, the U.S. Navy has developed a second-generation desalination unit that use 65% less energy than conventional technology.  It’s only in the prototype stage but the Navy is already looking beyond seagoing use, and has deployed an earlier version of the technology to provide emergency water supply to disaster areas.

Called the EUWP (Expeditionary Unit Water Purification Program) Gen 2, the new unit also offers a significant secondary benefit that applies to land operations.  By providing an on-site source for potable water, it eliminates the need to run convoys of tanker trucks.  The generators that power the EUWP units still use conventional fuel, but that could change.  If they could be adapted to run cost-effectively on solar power and other sustainable energy, the door is open to desalination on a mass scale.

A UK engineer has invented a device that harnesses wave power to pump sea water uphill, from where it can flow downhill to create hydroelectricity, raising hopes of a cheap, abundant source of renewable energy.

In trials, the device, called the Searaser, has pumped water more than 160ft above sea level, using little more than the natural motion of the waves. There are now plans for a much larger version, capable of pumping to a height of more than 650ft.

Inventor Alvin Smith reckons that each full-size device would be able to pump enough water to supply electricity to 470 homes. He also calculates that a fleet of 43,000 could generate enough power for a staggering 20 million households.