The blimp, everyone's favorite steampunk mode of transportation, has gotten an eco-friendly upgrade. Solar-powered airship Nephilios represents the culmination of a years-long French project to build a completely carbon-neutral flying machine.

In a first for blimps, what's on the outside of the ship's main balloon is just as important as what's contained inside. Although the ship is held aloft by the helium gas inside its nylon and polyethylene aluminum frame, it's the solar cells on the outside that provide all of its power. Producing as much as 2.4 kilowatts, the cells provide the power necessary to turn the blimp's two red propellers, which can let Nephilios achieve top speeds of 25 miles per hour. That's fast enough to get the craft across the English Channel, its first major test, in about an hour.

Nephilios measures 72 feet long and 18 feet wide. It's the end result of Projet Sol'r, a collaborative effort by a number of French universities and technical schools. With the stated goal of creating the first carbon-neutral airship, the designers had hoped to cross the English Channel last year in time for the centennial of Louis Bleriot's historic crossing of the Channel in an airplane; however, various delays have pushed the launch back a year. Nephilios is currently undergoing its final tests before making the crossing as soon as next week.

[Projet Sol'r via Inhabitat]