Meeting the commercial aviation industry’s net-zero emissions goals by 2050 will require widespread adoption of sustainable aviation fuels (SAF) and advanced technologies such as hydrogen and electric, according to modelling from Boeing’s global fleet emissions analysis tool, Cascade. 

In addition to its focus on scaling and enabling SAF on its aircraft, Boeing is studying hydrogen and hybrid-electric aircraft concepts across key areas including the physics, safety and certification challenges, future market applicability and technology development.

“SAF is required, but that doesn't mean that that's the only thing that we work on,” said Ellen Ebner, the sustainable technologies director for Sustainability & Future Mobility. “There are many advanced technologies that are going to make our aircraft more efficient or even change energy and propulsion technologies at the core of our products.”

Boeing Research and Technology, Commercial Airplanes’ Advanced Concepts and Aurora Flight Sciences teammates are partnering to undertake a series of studies to assess the unique promises and challenges of hydrogen and hybrid-electric technologies.

Why it matters: These studies will be a basis for identifying when key technology performance measures reach levels enabling a new potential aircraft or mission.

Hydrogen can be used on aircraft with direct combustion technology or with a fuel cell providing power to electric motors. Boeing has tested hydrogen propulsion and power technologies including gaseous and liquid hydrogen storage, direct combustion engines and fuel cell technologies over the past 15 years including flying the world's first piloted hydrogen fuel cell aircraft ever in 2008.

  • Rockets have long relied on hydrogen to generate the enormous energy needed to propel massive vehicles into orbit and deep space. From the Saturn V moon rocket to the space shuttle, cryogenic liquid hydrogen provided that boost. Recently, hydrogen, supercooled to minus 423 degrees Fahrenheit, fueled the Boeing-made core stage to power NASA’s Artemis I mission to the Moon.

Challenges: Using hydrogen in commercial aviation systems, however, is not straightforward. “The physical properties of hydrogen present big challenges,” Ebner said, “The molecules are very tiny, it has a low boiling point, and it has a low volumetric energy density.” 

  • Hydrogen storage requires either high pressure conditions or cryogenic temperatures and hydrogen takes up to four times the space as jet fuel even though it weighs less than half as much per unit of energy. Aircraft designs need to take these factors into account and accommodating hydrogen energy systems can impact flight physics and the ability to serve useful missions.

By the numbers: To store enough hydrogen onboard an aircraft to equal the energy of conventional jet fuel for a regional jet aircraft, it would require a 16,000 US gallon cryogenic storage tank.

Add to that: Boeing is also studying electric aviation including fully electric, hybrid-electric and more electrification of aircraft systems, as well as concepts that combine hydrogen fuel cells and electric batteries.

  • New batteries will enable electric aircraft for urban air mobility, such as the self-flying battery-electric aircraft being certified by Wisk. But batteries weigh too much for the longer flights that represent the vast majority of emissions.
  • Hybrid-electric propulsion technologies and more electrification of aircraft systems can combine the favorable energy density of hydrocarbon Jet-A fuel or SAF with battery and electrification technologies to improve payload and range capability. 


Brian Yutko, chief engineer for Sustainability & Future Mobility, summarizes the ways Boeing is researching electric propulsion. Yutko was recently named chief executive of Boeing joint venture Wisk Aero, and will be moving into the role on Feb 1, 2023. (Boeing video)

By the numbers: Boeing already enables 1.5 megawatts (MW) of supplemental electric power storage and management on the Boeing 787.

Boeing and Aurora Flight Sciences, a Boeing company, are working with GE Aerospace to develop a flying hybrid electric testbed as part of NASA’s Electrified Powertrain Flight Demonstration (EPFD) project. (GE Image)What’s next: Currently underway, the NASA-led Electrified Powertrain Flight Demonstrator program, with partners Boeing and GE Aerospace, is developing hybrid-electric powertrain technology envisioned to serve commercial aviation missions when in service. 

Go deeper: Chris Raymond discusses hydrogen propulsion in Fortune Magazine

By Ivan Gale



Aerospace Sustainability Foundations training

Boeing recently launched the Aerospace Sustainability Foundations training, a series of learning modules providing an educational and transparent view into its sustainability vision and priorities. 

The Aerospace Sustainability Foundations training provides foundational knowledge of the company’s sustainability efforts that align to the company’s values and priorities. 

It aims to educate employees about sustainability, why it matters to aerospace, and Boeing’s sustainability priorities and goals. Additionally, it aims to influence behavior changes at work, at home and in the community. Employees earn a sustainability badge or credential upon completion of this learning.

To access the Aerospace Sustainability Foundations training, click here.