Autoblog: "Intended to be an urban runabout, the two-seat Land Glider is fully electric and is extremely narrow to ease congestion in dense city centers and make it easier to find suitable parking spots.

Inside the cockpit, the Land Glider's pilot sits front and center behind a suitably futuristic instrument cluster and a steering wheel that looks like twin joysticks. According to Nissan, the steering operations are computer controlled through a drive-by-wire arrangement, so there doesn't seem to be a direct connection between the steering wheel and the car's four contact patches."

"Like cars, aircraft need the most power to get going, take off and climb. Planes need much less power for cruising. Flight Design's engine uses a 40-hp electric motor directly connected to a normal gasoline-burning 115-hp Rotax 914 airplane engine via belt drive to provide about five minutes of boost power.

The pilot pushes the single power lever forward for takeoff, and both motors are running to provide the equivalent of a 160-hp engine. Once the four-seat airplane is at altitude, the pilot reduces power for cruise and the electric engine is no longer delivering power. This leaves a 115-hp gasoline engine to provide the cruise power, which is more efficient than the 160-hp engine the hybrid system replaces.

Like its car cousin, the aircraft engine can also use regenerative braking. When a pilot reduces power for descent, the windmilling propeller is used to recharge the battery pack for the next flight."

(Hat tip David)

Via: Wired.com

The Antares DLR-H2 is based on the Antares 20E motor glider with a wingspan of 20 metres, constructed by Lange Aviation, a company based in the Rhineland-Palatinate region of Germany. With its fuel cell propulsion system, Antares has a cruising range of 750 kilometres, achieved in a flying time of five hours. In order to accommodate the fuel cell and the hydrogen supply on board the aircraft, two additional external load carriers were slung under the specially reinforced wings.

The current propulsion system permits maximum flying speeds of approximately 170 kilometres per hour.

The total efficiency of the drive system from tank to powertrain, including the propeller, is in the region of 44 percent, making it about twice as efficient as conventional propulsion technologies based on combustion processes. Systems powered by kerosene or diesel only contribute about 18 to 25 percent of their energy to propulsion.

Botte says the idea came to her several years ago at a conference on fuel cells, where they were discussing how to turn clean water into clean power. 'I wondered how we could do this better,' she adds - so started looking at waste streams as a better source of molecules from which to produce hydrogen.
Urine's major constituent is urea, which incorporates four hydrogen atoms per molecule - importantly, less tightly bonded than the hydrogen atoms in water molecules. Botte used electrolysis to break the molecule apart, developing an inexpensive new nickel-based electrode to selectively and efficiently oxidise the urea. To break the molecule down, a voltage of 0.37V needs to be applied across the cell - much less than the 1.23V needed to split water. 

The new SunCatcher is about 5,000 pounds lighter than the original, is round instead of rectangular to allow for more efficient use of steel, has improved optics, and consists of 60 percent fewer engine parts. The revised design also has fewer mirrors -- 40 instead of 80. The reflective mirrors are formed into a parabolic shape using stamped sheet metal similar to the hood of a car. The mirrors are made by using automobile manufacturing techniques. The improvements will result in high-volume production, cost reductions, and easier maintenance.

2008 was the first year that new power generation investment in renewables was greater than investments in fossil-fueled technologies.