Wedges of an orange generate enough current and electrical juice – 3.5 volts – to power an LED. The fruit’s citric acid helps electrons flow from galvanized nails to copper wire in this 14-hour exposure. This image was published in September’s Visions of Earth, a trio of photos that appear in each issue of National Geographic. (Photo by Caleb Charland/National Geographic)

A large storm cloud covers the Sydney CBD on March 5, 2014 in Sydney, Australia. A severe thunderstorm warning was issued for the Sydney metropolitan area late this afternoon with heavy rainfall due to cause flash flooding in areas. (Photo by Cassie Trotter/Getty Images)

People watch on from Marks Park as a thunderstorm gathers off Bondi Beach on November 13, 2020 in Sydney, Australia. The Bureau of Meteorology issued a number of severe weather alerts for the region today, with a high risk of thunderstorms and hail. (Photo by Brook Mitchell/Getty Images)

Aerial view of tourists cooling off at a water park in summer on June 27, 2023 in Zhengzhou, Henan Province of China. Zhengzhou Meteorological Observatory on June 27 issued an orange alert for high temperatures. (Photo by VCG/VCG via Getty Images)

Zhao Deli waves as he pilots his self-made “flying scooter” in Dongguan, Guangdong Province, China, 12 August 2018 (issued 16 August 2018). Inspired by a cartoon he watched as a child, Zhao Deli sold off his apartment in pursuit of his dream of building a flying scooter. (Photo by Aleksandar Plavevski/EPA/EFE)

A women wearing a mask to protect from extreme smog visits the Tiananmen Gate in Beijing December 8, 2015 as China's capital issues its first ever "red alert" for pollution. (Photo by Damir Sagolj/Reuters)

A model gets ready backstage during a body art festival in Almaty, Kazakhstan, March 23, 2016. (Photo by Shamil Zhumatov/Reuters)

People eat sushi off the body of a model at an opening event of a bar in Taiyuan, Shanxi province, August 22, 2015. (Photo by Reuters/Stringer)