AAs you prepare to fly on vacation and the many hassles that come with it, your worries about nerves and run-ins with criminals may overshadow the alarming consequences: air travel is a about 3.5 percent According to a 2021 study of all climate change caused by human activity. This may seem small, but this impact largely falls on a tiny percentage of the world's population. About 1 percent of all people on Earth are responsible for half of all carbon emissions from commercial aviation, and the vast majority of people on our planet do not fly abroad every year.
The aviation industry has been trying to solve the emissions problem for a long time. In fact, electric planes was at work for a century and a half. Along the way, all sorts of ambitious experiments were conducted to change the way we take off.
These include solar planes, the first of which recently turned 51 years old. On November 4, 1974, the Voskhod I remote-controlled aircraft hovered over the Mojave Desert in California for 20 minutes at a maximum altitude of about 300 feet. It was experimental monoplane– developed by AstroFlight under a federal government contract – to demonstrate that such an aircraft, with an “inexhaustible” source of energy, could “bask in the undiminished sun” in the upper atmosphere.
Sunrise I was only about 14 feet long and weighed almost 23 pounds. Six solar arrays were attached to the tops of the wings, and the craft was powered by a single motor and propeller.
At the time, solar cells were about half as efficient as current technology. The AstroFlight team quickly created an improved Sunrise II model that was 13 percent lighter and had 33 percent more power than its predecessor. During a test flight in September 1975, Sunrise II reached an altitude of 17,200 feet but suffered “severe” damage before reaching its target of 73,000 feet.
After half a century, why can't solar-powered planes take us to our vacation destinations and reduce carbon emissions? After all, in 2021 the aviation industry decided achieve net-zero carbon emissions by 2050.
The main limiting factor relates to the question posed President Donald Trump during his 2024 campaign: “What happens if the sun doesn't shine while you're in the air?”
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Energy harvested from the sun must be stored in batteries to provide continuous power when shooting through clouds or flying at night. But for now, scientists are still find out how to create batteries that are energy-dense enough yet light enough to power aircraft the size of jumbo jets on long flights.
Current battery energy density may need to quadruple for electric aircraft to “play a greater role in decarbonizing air travel,” Andreas Schafer, director of the Air Transport Systems Laboratory at University College London, said MIT Technology Review. This may not be possible with lithium-ion batteries, which currently power electric vehicles and many consumer electronics.
This pickle makes it difficult to build any all-electric aircraft, whether the electricity comes from hydrogen, solar power or any other source. Currently electric aircraft stay pretty petite and is limited to short trips with tiny manifests. For example, models as tiny as the Alia CX300 from Vermont-based Beta Technologies, which seats up to five passengers, intrigued major airlines and governments including Norway, China and the United Arab Emirates.
Compared to other types of electronic aircraft, solar-powered models face some unique barriers. When these planes soar through the skies, the solar panels don't always capture the energy. at the optimal anglenot to mention the annoying shadows from the clouds.
Aside from battery barriers, solar panels currently cannot provide enough power to keep jumbo jets in the air on their own. Rhett Allen, an assistant professor of physics at Southeastern Louisiana University, estimates that even if the wing of a Boeing 737 were covered in solar panels, it would provide 0.4 percent of the energy needed to maintain flight. “It’s very difficult to imagine any way to build a solar-powered passenger jet,” he said. wrote For Wired. Allen added that he is, however, more optimistic about electric aircraft more broadly.
Such problems have not stopped daredevils from pushing these aircraft to their limits. Between 2015 and 2016, an aircraft powered by more than 17,000 solar cells circled the world in 16 stages – these individual flights lasted up to five days in a row.
And in August of this year, Swiss pilot Raphael Domjan took off over the Valais Alps in Europe and broke the altitude record for solar aircraft. It reached an altitude of more than 31,200 feet, which is the cruising altitude of commercial flights.
While you probably won't be flying to Thanksgiving on a solar plane this week, we could make the transition to affordable, low-emission flights in our lifetime.
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