The auto industry is developing alternatives (i.e. hybrid and electric) to the gasoline-powered engine. But pollution from aircraft is often overlooked. Solar flight could be one solution to this problem.
While cars and coal-fired power plants are worse for the environment, according to Yale Climate Connections, flying does significant harm. A 2010 study from the University of Cambridge and MIT estimated that the emissions from cruising aircraft alone were responsible for around 8,000 premature deaths each year. That estimate doesn’t include deaths from the pollution caused when aircraft take off and land. According to the Center for Biological Diversity, airplanes may generate 43 gigatons of pollution by 2050 — nearly 5 percent of earth’s remaining carbon budget.
Researchers and industry are looking for ways to reduce planes’ use of fuel, according to National Geographic, including more energy-efficient engines, more aerodynamic shapes and even a coating that would prevent bugs from sticking to the fuselage, thereby reducing drag. Simply being more operationally efficient could save a lot of fuel and reduce emissions, according to PBS.
Instead of incremental measures, some innovators want to change the very nature of aircraft.
One milestone in this search began back in 1982, when Scaled Composites founder Burt Rutan started to develop an aircraft that could fly around the world without stopping or refueling. To do this, he needed to design the lightest, most efficient plane possible. The plane, christened Voyager, used an innovative construction method, according to the Experimental Aircraft Association: a sandwich of paper honeycomb and graphite fiber that was molded and oven-cured. The resulting craft weighed just 939 pounds, sans fuel.
The Voyager, piloted by Burt’s brother Dick Rutan and Jeanna Yeager, successfully completed its trans-global flight on December 23, 1986, after flying nonstop for nine days. Today, Scaled Composites is part of Northrop Grumman and continues to push the envelope of the possible through rapid prototyping using advanced materials.
While measures to reduce fuel and emissions are necessary, some have a bigger dream: flying with clean, renewable energy from the sun.
In 2004, Bertrand Picard, a Swiss psychiatrist who had previously company-piloted the first trans-global flight in a balloon, set out to prove the viability of solar energy by flying around the world in an aircraft powered only by the sun.
Working with André Borschberg, a Swiss entrepreneur and pilot, began work on a solar plane. In July 2005, their first plane, the Solar Impulse, completed a flight from Hawaii to Japan in five days. It was the longest solo solar flight in history.
In 2016, Bertrand Piccard and Borschberg set out again. This time, they overcame the challenges and Picard completed the 40,000 kilometer flight, this time solo.
On completing the flight, Picard told the Guardian, “I hope people will understand that it is not just a first in the history of aviation, but also a first in the history of energy.”
Picard remains committed to furthering the development of solar-powered and clean-energy travel. In November 2016, his organization launched the World Alliance for Clean Technologies during the UN Climate Conference.
Solar Flight is another company working on sun-powered aircraft. It’s developing planes for high-altitude, long-distance flights and a six-seat transport craft. It successfully completed a multi-stop, trans-American journey in 1989 and has successfully flown a two-seater.
Meanwhile, the sky isn’t quite the limit. In December 2016, Raphaël Domjan, a self-described eco-adventurer, unveiled SolarStratos, which he hopes will be the first manned, solar-powered airplane to penetrate the stratosphere.
All this innovation relies on industry to come up with lighter, stronger materials, more advanced sun-powered engines and more efficient solar cells. The goal of cleaner skies through solar flight could be within our reach.