The Possibility of Powering a Light Aircraft by Releasing the Energy Stored in Hydrogen within a Fuel Cell Stack

In this work, we examine the possibility of converting a light propeller-driven aircraft, powered by a spark-ignition, reciprocating piston, and internal combustion engine running on AVGAS, into one powered by an electric motor driven by a proton exchange membrane fuel cell stack running on hydrogen. Our studies suggest that storing hydrogen cryogenically is a better option than storing hydrogen under pressure. In comparison to cryogenic tanks, high-pressure tanks are extremely heavy and unacceptable for light aircraft. We show that the modified aircraft (including batteries) is no heavier than the original, and that the layout of the major components results in lower movement of the aircraft center-of-gravity as the aircraft consumes hydrogen. However, we acknowledge that our fuel cell aircraft cannot store the same amount of energy as the original running on AVGAS. Therefore, despite the fact that the fuel cell stack is markedly more efficient than an internal combustion engine, there is a reduction in the range of the fuel cell aircraft. One of our most important findings is that the quantity of energy that we need to dissipate to the surroundings via heat transfer is significantly greater from a fuel cell stack than from an internal combustion engine. This is particularly the case when we attempt to run the fuel cell stack at high current densities. To control this problem, our strategy during the cruise phase is to run the fuel cell stack at its maximum efficiency, where the current density is low. We size the fuel cell stack to produce at least enough power for cruise, and when we require excess power, we add the energy stored in batteries to make up the difference.