While the pandemic has greatly reduced all types of travel over the past year, including air travel, that trend is likely to reverse itself quickly as vaccines and other measures conquer the threat of COVID-19. With travelers itching to get out of their homes and explore the world again, the question of how to make aviation greener will become essential for the industry to answer.

Reducing greenhouse gas emissions is a global priority and the airline industry has a significant role to play since it contributes about 3% of the world's total. Scientists are hard at work developing and testing viable alternatives that will allow for safe and sustainable flights using green energy.

Here Comes the Sun

In 2015-2016, two adventurous entrepreneurs flew an aircraft dubbed the Solar Impulse 2 around the world without using an ounce of liquid fuels. Powered entirely by the power of the sun, the plane flew 25,000 miles over a total of 14 months and was hailed as an engineering triumph. The creators of Solar Impulse 2 acknowledge that solar-powered commercial flight will not be practical anytime soon. Still, they believe their accomplishments will lead to significant innovations in the use of solar panels worldwide.

You can watch the incredible journey of Bertrand Piccard and Andre Borschberg from initial inspiration to final triumph in The Impossible Flight, a documentary by NOVA originally aired on PBS in 2018.

Another practical use of solar power in the airline industry involves airports. The large expanse of space surrounding an airport can be used to create solar farms, which would help power airport operations and offset carbon emissions. Some airports have already implemented this technology, and more are sure to follow suit.

Alternative Fuels Are Hot

Could biofuels be the wave of the future for air travel? Serious research and experimentation are underway to determine whether fuel made from plants such as grass or even algae is feasible. Known as cellulosic biomass, these green components show promise but currently cost about three to four times as much as conventional jet fuel. Scientists are optimistic that the cost will fall quickly once large-scale production is possible.

Another alternative fuel source under serious consideration is the fuel cell. This relatively new technology involves converting hydrogen into electricity and could dramatically decrease carbon emissions from aircraft. Hydrogen is three times denser than standard jet fuel, offering great opportunities for increased efficiencies in flight.

In October of 2020, the first commercial-size aircraft powered solely by hydrogen fuel cells flew for 15 minutes, proving that this alternative power source has real potential. Several companies are currently developing aircraft powered by hydrogen as well as hybrid-electric models that aim to reduce carbon emissions by about 75%.

Airplane Design is Revolutionary

Another possible path to reducing the airline industry's carbon emissions doesn't involve fuel at all but rather the aircraft's design itself. So far, the most promising redesign involves the plane's wings. Researchers at NASA and Boeing have been working together to produce and study a lighter, longer, and thinner wing. Studies indicate this revolutionary wing design could reduce fuel consumption and carbon emissions by at least 50% over today's typical aircraft.

At the University of Southern California, researchers are completely re-imagining how planes are designed. Taking inspiration from the way birds soar easily through the air, they wondered what would happen if aircraft were designed to look like birds, with a shorter body, flat tail, and bendable wings. They estimate a 10% increase in efficiency with their bird-like plane over conventional aircraft and working hard to prove their concept.

As the world begins to return to normalcy following the pandemic, travel is expected to increase dramatically. People are anxious to visit loved ones, explore new places, and take their long-postponed vacations. Air travel is increasingly popular due to its speed and convenience, but that ease comes at a cost to the environment. Exploring green technologies is a win-win-win situation for the airline industry, the flying public, and the environment.