Swiss pilot Bertrand Piccard prepares for a test flight of the solar-powered Solar Impulse 2 experimental aircraft in Payerne November 13, 2014. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. An attempt to fly around the world in stages using only solar energy will be made in 2015. (Photo by Ruben Sprich/Reuters)

Dutch artist Daan Roosegaarde paid homage to Vincent Van Gogh's famous “Starry Night” painting by creating a glowing bike path relying on solar-powered LED lights. The 650-yard route which opened November 12, 2014 extends between Eindhoven and Neunen, Netherlands, where Van Gogh spent part of his life. Its the first event marking the 125th anniversary of Van Gogh's death July 29, 2015. (Photo by Pim Hendriksen/Studio Roosegaarde)

A farmer is seen hanging from a tree during a rally organized by Aam Aadmi (Common Man) Party (AAP) in New Delhi April 22, 2015. The farmer hanged himself from a tree during a political rally in New Delhi on Wednesday, in what appeared to be a desperate protest against the hardship felt by many people scratching a living in rural India. Four people climbed the tree to try to save the man after he was seen hanging. (Photo by Adnan Abidi/Reuters)

A man holds a metal bar as a weapon during a training day for former soldiers and volunteers train in a makeshift camp in the outskirts of Port-au-Prince, Haiti, October 28, 2015. Haiti disbanded its abusive armed forces two decades ago but uniformed veterans and young recruits are resurfacing to add another destabilising factor to the volatile Caribbean nation already dealing with a political vacuum. (Photo by Andres Martinez Casares/Reuters)

In this March 21, 2015 photo, 15-year-old Guerline Augustin carries river water on her head, back to a borderland encampment outside the southeast Haitian town of Anse-a-Pitres, Haiti. The encampment is filled with people who either fled or were forcibly removed from the neighboring Dominican Republic amid an immigration crackdown. Within the next month, authorities hope to move nearly 2,400 people out of six encampments by providing subsidies for them to rent homes for a year in southeastern Haiti. The International Organization for Migration is coordinating the effort with $2 million from a U.N. emergency fund. (Photo by David McFadden/AP Photo)

A stuffed rabbit doll sits among children's beds standing in the abandoned kindergarten of Kopachi village located inside the Chernobyl Exclusion Zone on September 29, 2015 near Chornobyl, Ukraine. Kopachi, a village that before 1986 had a population of 1,114, lies only a few kilometers south of the former Chernobyl nuclear power plant, where in 1986 workers inadvertantly caused reactor number four to explode, creating the worst nuclear accident in history. (Photo by Sean Gallup/Getty Images)

In this April 23, 2015 photo, friends Jia Haixia, left, and Jia Wenqi work to plant a tree in a field in Yeli village near Shijiazhuang city in northern China's Hebei province. For the past 13 years, Jia Wenqi, who has no arms, and Jia Haixia, who is blind, have worked together to plant and water more than 12,000 trees near their village. (Photo by Helene Franchineau/AP Photo)

An aerial view of the holy Muslim Shiite shrine of Imam Moussa al-Kazim as pilgrims gather to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. The anniversary of 8th century Shiite Imam Moussa al- Kazim drew tens of thousands of Shiites from all walks to converge on his golden-domed shrine in northern Baghdad. The pilgrims typically march to the shrine while hundreds of tents are erected to offer them free food, drinks and services. (Photo by Hadi Mizban/AP Photo)