Fire from the explosion of a natural gas pipeline in Ukraine's Urengoi-Pomary-Uzhgorod in Poltava region, on Tuesday. Ukrainian Ministry of Emergencies/EPA/Landov hide caption

itoggle caption Ukrainian Ministry of Emergencies/EPA/Landov

A worker turns a valve at an underground gas storage facility near Striy on Wednesday. Russia has said state-controlled exporter Gazprom will supply China with natural gas via a Siberian pipeline beginning in 2018. Gleb Garanich/Reuters/Landov hide caption

itoggle caption Gleb Garanich/Reuters/Landov

A rendering of the world's largest vessel, the Shell Prelude, which comes in at just over 1,600 feet. It has just left its dry dock in South Korea, where it is being built. It will eventually head toward Australia, where it will be anchored off the coast and used as a liquefied natural gas facility. Shell hide caption

itoggle caption Shell

An out-of-control natural gas well in the Gulf of Mexico continued to burn Wednesday after it blew out and caught fire. Beams supporting some of the "Hercules 265 jack-up rig" have collapsed. U.S. Coast Guard via AP hide caption

itoggle caption U.S. Coast Guard via AP

China and India are projected to propel coal's challenge of oil as the world's top energy source within the next five years, according to a new study. Here, a man rides a bicycle toward a coal-fired power station in China's Guangdong province last year. Mark Ralston/AFP/Getty Images hide caption

itoggle caption Mark Ralston/AFP/Getty Images