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 young exhibitor arrives with her kitten on a lead at the National Cat Club show at Crystal Palace, London. (Photo by Fox Photos/Getty Images). 2nd December 1931

Police walk past a burning car during riots in Birmingham City Centre on August 8, 2011 in Birmingham, England. After three nights of rioting and looting in and around London, the chaos is starting to spread to other cities around Britain. (Photo by Jeff J Mitchell/Getty Images)

In this November 27, 2019 photo, Wadlande Pierre, right, talks on her mobile phone as she helps her mother, Vanlancia Julien, center, at their fruit and vegetable stand on a sidewalk in Delmas, a district of in Port-au-Prince, Haiti. Pierre, 23, said she temporarily moved in with her aunt in the southwest town of Les Cayes to escape the violent protests in Port-au-Prince. However, she had to move back to the capital because there was no gas, power or water in Les Cayes, and food was becoming scarce. (Photo by Dieu Nalio Chery/AP Photo)

A girl looks out of a car at a checkpoint set up by Venezuelan security forces in Taguanes, Venezuela, February 21, 2019. (Photo by Andres Martinez Casares/Reuters)

Hamar women dance before a bull jumping ceremony in Ethiopia's southern Omo Valley region near Turmi on September 19, 2016. The Hamar are a Nilotic ethnic group in Ethiopia. The construction of the Gibe III dam, the third largest hydroelectric plant in Africa, and large areas of very “thirsty” cotton and sugar plantations and factories along the Omo river are impacting heavily on the lives of tribes living in the Omo Valley who depend on the river for their survival and way of life. (Photo by Carl De Souza/AFP Photo)

The Lumix GX1 single lens reflex (SLR) camera with 14-42 mm powerzoom lens is displayed at the Panasonic booth at the 2012 International Consumer Electronics Show at the Las Vegas Convention Center January 10, 2012 in Las Vegas, Nevada. The new camera comes with an external viewfinder and flash and an ISO up to 12,800. The camera as shown sells for USD 949; the camera body alone is USD 799. (Photo by Ethan Miller/Getty Images)

Honorable Mention: “The Storm”. During I was taking photo with my nephew, the storm came and I caught this beautiful moment. Photo location: Kocaeli, Turkey. (Photo and caption by Aytül Akbaş/National Geographic Photo Contest)