Fuel Cell Concept for Flight

The Fuel Cell

In 2007 I purchased another kit, Velocity XL-5 RG (5-seater requiring a 300hp engine) - on which I am building currently. As Avgas is quite costly and not available in many remote areas, I was looking at a diesel powered engine using Jet fuel as an alternative. But all my research has failed to come up with a satisfactory aviation solution. I have thus since been looking at electric flight and would like to do a viability study to see if I could manage to power this plane for long electric flight (non hybrid). So far I have understood that batteries are not the way to go as they are heavy and could be dangerous due to their chemical composition. Hydrogen fuel cells have been optimised in recent years - this is how I have come to your fuel cells (FCs) which yield a superb performance to weight ratio. I was particularly looking at your model S3-455c. My idea would be to have two of the S3-455c to get close to my required 300hp - also to have two independent circuits to isolate one S3-455c from the other. If you have maybe updated versions of the S3s or a better fit for my requirements (AutoStack-CORE?) - please give me your recommendations. Other questions that may arrise, is how to store the hydrogen - as the common e-car manufacturers like Toyota, Honda and Hyundai seem to use high-pressure hydrogen storage tanks - not sure if one can use an efficient hydride for sorage as an alternative. The electronics around the FC would also need to be considered for flight: -Gas flow - indicator. -Wetting of FC (after aircraft standing for long periods of time or otherwise.) -Regeneration of electricity during landing when e-motor is windmilling (much like a car when braking). -Testing of FC efficiency before take-off. -Can heat generated by FC be used to heat the cabin? - can get cold at higher altitudes. -Will FC still operate (normally) at higher altitudes? Of course the cost of the FC will also be a factor in the viability of this project.

Hydrogen Tanks

Looks like the high pressure hydrogen tanks are the way to go and there are a variety of lightweight tank manufacturers that can custom build a tank to your specifications. A tank with a volume of 25 litres (water volume) will harbour 1 Kg of hydrogen at 700 bar. I can store about 80L of H-tanks on each side of inner wing (the old fuel tanks which could cayy about 150L of fuel each side). It seems that between 15 and 20Kg of compressed hydrogen at 700 bar could be enough for long distance travel - JHB to CT non stop.

Electric Motor

Siemens motor is on hold since fatal accident - looking at alternatives.

Propeller

Possibly MT - not sure if constant speed is needed as electric motor can rev higher.