Indonesia is the world's fifth-largest coal producer but the largest exporter, surpassing Russia, the world's sixth-largest coal producer. The BP Statistical Review of World Energy, released in June 2016, reported national coal production in 2015 at 241.08 Mtoe. Most Indonesian coal is of medium (between 5100 and 6100 cal/gram) and low (below 5100 cal/gram) quality. [link: Indonesia Eksportir Batu Bara Terbesar Dunia pada 2014]
Meanwhile, the world's largest coal producer is China, with 1,827.01 Mtoe. The United States is second with 455.16 Mtoe, followed by India in third place with 283.86 Mtoe. Russia, ranked below Indonesia, produced 184.46 Mtoe.
Coal, a type of fossil fuel, is an energy source for power plants and fuel for steel and cement production. At the current production rate, global coal reserves are estimated to last approximately 112 years. The largest coal reserves are found in the United States, Russia, China, and India.