Ndebele, Bright BNaidoo, PurushaRagimana, PhumudzoMakhubo, Mamokete2026-01-052026-01-052025-09http://hdl.handle.net/10204/14556Long-endurance aviation propulsion is currently dominated by carbon-based fuels. However, due to climate change, which is largely attributed to carbon dioxide (CO2) emissions from human activities, aviation contributes approximately 4 %, a more climate friendly fuel is sought. Hydrogen (H2), particularly in proton exchange membrane (PEM) fuel cells, offers a promising carbon-neutral alternative. To assess its viability, a mathematical model of a commercial fuel cell was developed to evaluate efficiency under varying ambient conditions representative of Africa climates and at high-altitude scenarios. The Nernst equation – modified to include terms for activation, polarisation, and Ohmic losses – was used to model an experimentally determined polarisation curve (current against cell voltage curve). When fit to experimental data the modified Nernst equation parameters were found to be: A = 0.0356 V, I0 = 0.0212 Amperes, Rint = 0.0059 Ohms, and Imax = 150 Amperes where A, I0, Rint and Imax are the Tafel slope, limit current, internal resistance, and maximum limit current, respectively. The influence of pressure and temperature were determined by varying the partial pressure of oxygen and temperature in the Nernst equation resulting in an efficiency map (𝜂(𝑃𝑂2,𝑇)). The maps showed that efficiency is high for high ambient pressure and low ambient temperature. However, the influence of ambient pressure and temperature were found to be insignificant compared to the influence of power drawn.FulltextenFuel cellsHydrogenGlobal warmingConference PresentationN/A