Daimler Chrysler Airbus to produce Hydrogen aircraft
Hydrogen has triple the energy as ordinary aviation fuel, so the aircraft can carry larger payloads. However liquid H2 is 12-times as bulky, so a typical aircraft will require fuel tanks 4-times the normal size. Also hydrogen is usually stored in preferably spherical, but often short cylindrical, tanks so as to minimize the surface area-to-volume ratio. These tanks require less insulation to prevent heat transfer to the hydrogen. This means that the fuel cannot be stored in the wings like a normal aircraft. There are a number of configurations that are being tested. Check it out:
http://www.flug-revue.rotor.com/FRHeft/FRH9809/FR9809k.htm
