jakarta jan 1 reuters  indonesia has banned coal exports in january due to concerns over low supplies for domestic power plants local media reported on saturday citing a letter sent by the energy ministry the southeast asian country is the worlds biggest exporter of thermal coal exporting around 400 million tonnes in 2020 its biggest customers are china india japan and south korea indonesia has a socalled domestic market obligation dmo policy whereby coal miners must supply 25 of annual production to state utility perusahaan listrik negara pln at a maximum price of 70 per tonne well below current market prices in the letter cited by local media kumparan the ministry instructed that all coal at harbours should be stored to supply power plants and independent power producers ipp the export ban will be evaluated and reexamined based on the stock realisation of coal stocks for plns power plants and ipp the letter said the ministry and pln did not immediately respond to reuters requests for comment while the indonesian coal miners association saidit would issue a statement regarding the export ban in august 2021 indonesia suspended coal exports from 34 coal mining companies it said failed to meet domestic market obligations between january and july last year  indonesia is among the top 10 global green house gas emitters and coal makes up around 60 of its energy sources reporting by bernadette christina writing by stanley widianto editing by kim coghill