While air flight is considerably cheaper and more fuel-efficient than other modes of transportation, land vehicles especially, there’s a lot that can be done to improve the industry’s sustainability. For instance, the aviation industry’s contribution to rising CO2 levels has grown from about 0% to 2% over the last century because of how often commercial flights take place.
What can we do to make green aviation possible? The answer hinges on the development of cleaner, more efficient fuel cells.
Chasing New Fuel
In September 2020, Airbus announced plans to create a hydrogen-powered aircraft and have it flying by 2035. In those designs were concepts for three different aircraft, all of which will be powered by batteries and hydrogen, serving as the fuel for power-hybrid and energy-efficient engines.
As long as the hydrogen is readily available, hydrogen fuel cells won’t ever go flat, like what we see in conventional batteries. Hydrogen fuel cells work like this: Pressurized hydrogen remains in the tank, and when it interacts with oxygen, contained in the air, it starts a chemical reaction and produces electricity.
The problem, however, is that both the hydrogen — in liquid or gaseous form — and its fuel cells are heavier than traditional sources, namely aviation or fossil fuels. That, combined with the unique requirements of flight, like maintaining hydrogen fuel below its 20K boiling point, or outfitting tanks to withstand high air pressures, are considerable obstacles.
Yet another issue is the current fueling infrastructure, once hydrogen is adopted. Where will hydrogen-fueled planes fuel up?
At least, that’s the case right now. Hopefully, time will remedy most of these issues as more capable technologies are created.
Solar Flight, Anyone?
Alternatively, planes can run on solar power. In 2016, two pilots were able to fly a solar-powered plane called the Solar Impulse 2 around the world successfully.
The design of the craft they used could be replicated for commercial flight. However, the plane only traveled at 45 miles per hour and took 505 days to fly 26,000 miles. That’s way too slow for conventional travel.
We’re much closer to seeing hydrogen-fueled commercial craft in the air than we are solar. Until manufacturers can figure out a viable fuel cell design, things are relatively stagnant.
Adopting More Sustainable Jet Fuels
In the meantime, we are seeing airlines moving towards more sustainable fuel sources. In 2008, Virgin Atlantic was the first airline to complete a biofuel flight, from London to Amsterdam. The catch is that only one of its four fuel tanks contained a 20% mixture of biofuel.
Even if we won’t see a majority of fuel converted to biofuel anytime soon, using an alternative for a portion of one’s needs qualifies as a carbon offset. Carbon offsetting is an eco-friendly approach that calls for living more carbon-neutral lifestyles and engaging in more sustainable practices. In other words, cutting out as much use of fossil fuels as possible is a move in the right direction, and what Virgin Atlantic started with its biofuel flight is commendable.
Several other airlines have followed suit, including Lufthansa and Qantas. The latter flew from Los Angeles to Melbourne, Australia, with a fuel mixture of 90% conventional jet fuel and 10% mustard seed oil.
Innovation Can Take Time
Commercial hydrogen, hybrid, and electric-powered aircraft are coming. However, it will take some time to not only perfect the efficiency of these technologies, but also the safety. Hydrogen fuel cells, for example, must be more lightweight and more resistant to high pressures.
Sustainable fuels are helping to bridge the emissions gap in the meantime, but they could certainly stand to see more widespread adoption. Still, it’s important to consider the carbon offsets they provide, which cut down on carbon emissions even if only by a small amount.
All in all, the race to create more effective, energy-efficient, and sustainable aviation fuel cells is on!
Jane Marsh is the Editor-in-Chief of Environment.co. Jane covers topics related to climate policy, sustainability, green technology, renewable energy and more.