Hydrogen-Electric Aircraft Technologies and Integration: Enabling an environmentally sustainable aviation future

As the global community grapples with growing concerns of a changing climate, many eyes have turned to the sustainability of the transportation sector. In the United States, transportation is currently the leading category contributing to all greenhouse gas emissions, producing more emissions per year than the electricity generation, industry, commercial and residential, and agricultural sectors individually. As various transportation modes transition to more sustainable models, such as with the use of battery-electric vehicles, the aviation sector has struggled to identify effective solutions for future sustainability goals, largely due to the difference in power and energy requirements of aircraft, as compared to other vehicles. One solution currently being explored by a number of academic, government, and industry researchers is the use of hydrogen-energy systems on aircraft. Although practical challenges do exist in hydrogen adoption on aircraft, lightweight energy storage mediums remain appealing and technically viable solutions for future generations of air vehicles. More specifically to hydrogen-electric aircraft configurations, further significant developments are required in key technologies, such as high-temperature fuel cell power plants, electric machines, power electronics, power transmission systems, airframe designs, and propulsion system integration. However, there nevertheless remains a line-of-sight pathway to future zero-emissions aircraft capable of meeting or exceeding the performance of existing air vehicles. As described in this article, the advantages of future hydrogen-electric aircraft reside not in one specific technology but rather in the synergistic integration of a multitude of components into innovative aircraft configurations. These developments are explained using a candidate hydrogen-electric aircraft designed to fill the same mission-performance characteristics as a single-aisle reference aircraft, while producing zero carbon dioxide (CO
₂
) and nitrogen oxide emissions across the entirety of the aircraft’s long-range mission.