Image caption: Hydrogen fuel cells could help decarbonize the aviation industry. Image Credit: Sean MacEntee / Openverse.
Script by: Sophie Wenzlau Audio by: Emma Mott Blurb by: Megan Chan
The Carbon Cost of Aviation
Transportation is a leading contributor to global greenhouse gas emissions, with air travel playing a significant role. In the United States, the transportation sector accounted for 29 percent of all greenhouse gas emissions in 2021. Commercial airplanes and large business jets contributed ten percent of U.S. transportation emissions, and three percent of the nation’s total greenhouse gas emissions, according to the U.S. EPA. Despite reduced travel during the COVID-19 pandemic, air travel demand has rebounded and is expected to continue growing.
Hydrogen’s Potential to Power Aviation
Hydrogen offers three times more energy per kilogram than jet fuel and emits no toxic fumes when combusted. Its higher energy density and capacity for consistent electrical power make it a promising potential energy source for aircraft.
Compared to aircraft powered by fossil fuels, there are many potential advantages to aircraft powered by hydrogen: zero emissions, increased efficiency, greater power, a longer operational lifespan, and benign byproducts (water and heat). For heavy transport in particular, hydrogen may be a promising option for reducing greenhouse gas emissions where the lower energy density (and accompanying lower range), high initial costs, and slow recharging performance of batteries are disadvantages.
While promising, hydrogen fuel cells are a relatively new technology. Current tests by companies like ZeroAvia suggest that commercial viability of hydrogen powered aircraft is years away. Because hydrogen fuel is difficult to transport, major infrastructure changes, including on-site hydrogen production at airports, are needed to make this technology practical and scalable; significant funding is needed to bolster research to support this transition. Moreover, the production of hydrogen fuel can itself be a carbon intensive process because it takes energy to produce hydrogen fuel. When that energy comes from fossil fuels, the hydrogen production process can result in significant carbon emissions. But when that energy comes from renewable sources, the process can be emission free.
About our guest
Val Miftakhov, founder and CEO of ZeroAvia, started the company in 2018 with the goal of making the future of aviation more sustainable. Prior to ZeroAvia, Miftakhov founded eMotorWerks, an electric vehicle infrastructure company, where one of his many projects was creating high-tech EV charging models. He earned his PhD in physics at Princeton University.
The Growth in Greenhouse Gas Emissions from Commercial Aviation, Environmental and Energy Study Institute
Working to Build a Net-Zero Sustainable Aviation System by 2050, U.S. Federal Aviation Administration
Aviation and global climate change in the 21st century, Atmos Environ
Airplane Pollution, Transport & Environment
Ethan: I’m Ethan Elkind, and you’re listening to Climate Break. Climate solutions in a hurry. Did you know that air travel accounts for 2.5 percent of global emissions? Today’s proposal: building zero-emission airplanes. We spoke with Val Miftakhov, the CEO of ZeroAvia, about their efforts to build the world’s first zero-emission passenger jet powered by hydrogen fuel.
Dr. Miftakhov: We wanted to really address the big problem that we have in sustainability of aviation. It’s one of the fastest growing areas of transportation. And nobody really has a solution for sustainability issues there. So, we thought that we would start a company that would solve sustainability of aviation at scale.
Ethan: Hydrogen can offer longer range flight compared to batteries, which may make it a superior zero-emission alternative for long-haul flights. Miftakhov also cited potential efficiency gains.
Dr. Miftakhov: We decided that hydrogen electric approach, which is hydrogen fuel cells, electric motors, all of that combined together, that approach is probably the best approach to get us the solution at scale. You have electric motors that never break. You have power electronics that never breaks. You have very efficient system, and at the same time, you get to use hydrogen as a very, very dense fuel. Hydrogen is three times more dense on a per kilogram basis. So, actually, we can see delivering the same or even better range in aircraft than jet fuel.
Ethan: To learn more about efforts to develop zero-emission airplanes, visit climatebreak.org.