Monte Carlo Simulation of Emissions and Energy Model of Civil Aircraft Concepts Propelled by Hydrogen Fuel Cells

Previous work has shown that, by using future low-carbon electricity for electrolysis, hydrogen fuel cells could be a candidate for low-carbon passenger airplane concepts. This conclusion was reached by conducting an optimization procedure where the total mass and volume of future aircraft were considered to be, at most, the same as today's aircraft, but the propulsion system and the energy carrier took up a different amount of the total mass and volume. However, such optimized conceptual designs and the resulting estimates of the overall energy consumption and carbon dioxide emissions, as well as the maximum range of the aircraft, rely on various inputs such as component efficiencies that have a large uncertainty. To identify the most sensitive components, a Monte Carlo simulation was undertaken in this paper, using the 2038 liquified hydrogen Boeing 787-8 and Cessna 172 models as examples of a large civil and a small short-range aircraft. It was found that the carbon emissions of the electricity grid, the mass of hydrogen per unit mass of fuel tank, and the fuel cell efficiency are the input parameters that produce the largest uncertainty in the overall conceptual design. Therefore, research and development into these input parameters and their associated components is especially important. A new estimate was obtained for the maximum range that each 2038 liquified hydrogen aircraft could travel at half the emissions of the conventional aircraft. There was a 95% probability that the Boeing 787-8 could travel between 1846 km and 15800 km and that the Cessna 172 could travel between 415 km and 4571 km. Although the uncertainty in these range estimates was high, both large and small liquified hydrogen aircraft could play a key role in a future aviation system. Even if they were only able to travel as far as lower estimates of their predicted range, the aircraft could still fill important niches within the industry.