Hydrogen Infrastructure Analysis Frameworks for Aviation Applications

While aircraft account for less than 10% of United States (U.S.) transportation energy consumption, it is the only mode expected to see sustained growth in energy demand through 2050. Currently, commercially available aircraft rely heavily on either jet fuel or leaded aviation gasoline. Over the past few decades, concerns have grown over the contributing effects that greenhouse gases, which are produced from fossil fuels, have on the environment. Due to these concerns, many aircraft manufacturers are pursuing the development of new generation aircraft that can leverage alternative, renewable fuels. The Federal Aviation Administration (FAA) is presently working toward certifying multiple novel aircraft and developing an environment to safely support this innovation. For airports and aircraft original equipment manufacturers (OEMs) that choose to be early adopters of hydrogen technology, the FAA needs to provide guidance for the associated support infrastructure. The FAA is collaborating with the National Renewable Energy Laboratory (NREL) on this research project to evaluate the impact of the anticipated demand for hydrogen as a fuel source on existing airport infrastructure. This study is intended to help reduce market barriers involving uncertainty in standards and operational requirements of hydrogen technology and airport infrastructure. By defining system-wide best practices in refueling systems and facility layouts, manufacturers, airports, and communities can be better prepared to participate in this emerging industry. Section 2 of this document is the culmination of a literature review that describes the current state and the anticipated future of hydrogen-related technology across various government organizations, industries, and academia. This work identifies existing goals and the maturity level of the industry to help define a realistic strategy and approach to implement hydrogen systems into the airport environment within a realistic timeframe. The technology areas cover production, storage, transport, and fueling as a supply chain of hydrogen. This report also briefly investigates hydrogen propulsion systems, such as fuel cell and combustion engines. Furthermore, this work organizes safety codes and standards to identify gaps in our current understanding. Presently, there are detailed standards regarding hydrogen technology, airport safety, and aircraft fueling. However, they are not consolidated as a unified set of codes and standards suitable for the airport environment. Preventive safety measures and emergency procedures must be identified as hydrogen will begin to be transported on to airport sites. These safety requirements must continue to mature as the airports adopt hydrogen technology in their proximity. Sections 3 and 4 of this study focus hydrogen aircraft demands, and airport infrastructure needed to support hydrogen technology. The examination of hydrogen production, storage requirements, delivery methods, refueling services, and safety requirements are critical to accommodate novel hydrogen aircraft in the airport environment. Learnings are applied to the LAX, SEA, PDX, and SFO airports to gain insight on: 1) space requirements for hydrogen infrastructure, 2) airport hydrogen infrastructure placement, and 3) cost and economic impacts of hydrogen infrastructure at each airport. Results show that each airport has space for hydrogen infrastructure, especially at hydrogen demand levels of around 1,000 kg/day. We also find that both hydrogen infrastructure cost and economic impacts become more favorable as hydrogen demand at the airports scale. This study is intended to provide a comprehensive understanding of hydrogen infrastructure that will enable energy-savings and emissions-reductions while illuminating pathways to transition from legacy systems to next generation aviation. The study should be used as a guide by airport and government officials, as well as industry leaders, to gain insights on how hydrogen and hydrogen infrastructure can be utilized for advance air mobility applications.