Making air travel truly sustainable is one of the biggest challenges facing the airline and aerospace industries. For every positive step taken by the industry as a whole, growing demand for air travel has essentially negated progress.
Now, Airbus says it's ready to make the next big leap.
The European planemaker unveiled three brand new concepts for the world's first zero-emission commercial aircraft. Each concept serves a different purpose, but each is powered by hydrogen, rather than traditional jet fuel.
Hydrogen is a relatively new alternative fuel concept for aviation. Until recently, most low- and zero-emission aircraft concepts focused on electricity, but
The aviation industry contributes as much as 2% to 3% to global manmade emissions, by most estimates. But with passenger numbers predicted to double to 8.2 billion annually by 2037, the share is likely to grow (especially as other industries decarbonize).
Although airlines have taken steps to reduce emissions, most of those are negated by market growth, and most of them are smaller, incremental steps. To make a real impact, an alternative to jet fuel is crucial.
"As recently as five years ago, hydrogen propulsion wasn't even on our radar as a viable emission-reduction technology pathway," Glenn Llewellyn, a vice president overseeing zero-emission aircraft development at Airbus, said in a press release. "But convincing data from other transport industries quickly changed all that."
Now, Airbus says the new planes could enter commercial service as soon as 2035. The company plans to "mature all the required hydrogen technologies" by 2025, allowing the following 10 years for aircraft development, testing, and certification. The first prototype should arrive by the late-2020s.
The European planemaker is considering two methods of using hydrogen to power an aircraft. The first, hydrogen combustion, works the same way as a normal internal combustion engine, but burns cleaner hydrogen instead of fossil fuels. The second, hydrogen fuel cells, converts energy stored in hydrogen and oxygen atoms to generate electricity.
Airbus' three conceptual aircraft, collectively codenamed ZEROe, are powered by a hybrid-system, using both hydrogen combustion and hydrogen fuel cells.
Here are the three zero-emission Airbus planes that could revolutionize green flight, and that you might find yourself aboard in the 2030s.
Airbus' hydrogen-powered ZEROe propeller aircraft
Airbus' first design is a surprising one, given that the planemaker does not currently manufacture turboprop, or propeller, aircraft.
However, propeller planes are more efficient at lower speeds, and can often take off from shorter runways, making them an attractive option for some airlines.
The ZEROe hydrogen plane would seat up to 100 passengers and fly routes up to about 1,000 nautical miles. The liquid hydrogen storage and distribution system would be located behind the rear pressure bulkhead, Airbus says.
The Airbus ZEROe jet
The turbofan — jet — powered airplane might look familiar, aside from its unusually long, swept wings. With a capacity of 120 to 200 passengers, a range of a bit over 2,000 nautical miles, and a traditional tube with wings design, the ZEROe turbofan resembles the current Airbus A320 family — aside from its fuel source.
Like on the turboprop, liquid hydrogen would be stored in tanks behind the rear pressure bulkhead.
The ZEROe blended-wing aircraft
The most futuristic of the three concept aircraft — and the only one with a radically different design than the airplanes of today — the ZEROe "blended-wing" design will give Airbus' engineers and potential future customers the most options to play with.
The abnormally wide body means there will be many different possible ways to store liquid hydrogen, and for airlines to lay out their cabins. Any design would be finalized as Airbus finishes developing the technology that will go into the planes, and determines what would be the most efficient.
This aircraft would carry up to 200 passengers, and Airbus says it would have a "similar" range to that of the turbofan jet plane. It would also be powered by two turbofan jet engines, which would be shaped differently than on the traditional turbofan plane.
"Hydrogen has a different volumetric energy density than jet fuel so we have to study other storage options and aircraft architectures than existing ones," Jean-Brice Dumont, an executive vice president of engineering at Airbus, said in a statement. "This means the visual appearance of our future zero-emission aircraft will change. These three configurations provide us with some exciting options for further exploration."
The quest for a carbon neutral airplane
Airlines and aerospace manufacturers have been searching for ways to make their operations greener for years.
The United Nation's aviation body, the International Civil Aviation Organization, forecasts greenhouse gas emissions from airplanes could increase significantly in the next few decades. (These numbers do not account for the travel-suppressing impact of the COVID-19 pandemic.)
To date, airlines have addressed climate change mostly by replacing older fleets with new, more efficient aircraft, and making incremental changes where possible. For example, American Airlines said it decreased fuel use by 4% by installing small vertical pieces, called winglets, onto the ends of wings on most of its planes. The devices improve the wing's lift by changing its aerodynamic profile.
Airlines have also focused on purchasing carbon offsets. However, offsets don't directly reduce emissions; instead, they fund ecofriendly activities that have a positive effect, theoretically cancelling out the negative impact of an action — airlines are increasingly offering them to passengers for their flights. However, offsets have been criticized as ineffective.
Biofuels are another option which is being implemented today.
However, there's limited supply right now, which makes scaling up difficult. Plus, some biofuels use stock feeds that are even less efficient than traditional fossil fuels, meaning emissions end up even higher.
There are even more complications, including threats of deforestation in order to grow stock for the biofuels — that could even accelerate climate change.
Ultimately, the only thing that will make a major impact on emission levels is reliance on a new fuel source. Although Airbus says its hydrogen planes are still 15 years away, the concept could develop into the next era of air travel.