A European company claims it's been joined by Korean car-maker Daewoo to produce a "water-powered" car. Swiss firm Ethos says it will have a prototype built December 2008 in partnership with Daewoo, with a mass production version arriving in 2009.

The company says it uses a new method to split water into hydrogen and oxygen. "The technology was there in 1968", argues Ethos CEO Peter Aldred. "With the advent of new technologies, even more efficient ways of disassociating water molecules have now been discovered".

Previous water power cars have been debunked. Water car proponents have suggested a method to split water into hydrogen and oxygen, either using a battery and electrolysis or metal hydrides. The hydrogen and oxygen are then recombined, either in a fuel cell for a chemical reaction that creates electricity (similar to the Honda FCX), or by burning the hydrogen in a combustion engine (much like the BMW Hydrogen 7).

There's just one problem with both solutions. They require energy to split the water in the first place, and that energy could be used more efficiently to directly power the car.

Earlier this year Reuters reported on a Japanese water-powered car based on the same design as G-Wiz, the Genepax. A production version of the car failed to materialise.