PLN to Retrofit Coal-Fired Plants to Use Low-Calorie Coal

State electricity firm PT PLN (Persero) will retrofit its coal-fired power plants (PLTU) to enable them to use low-calorie coal, a move aimed at preventing rolling blackouts. President Director Darmawan Prasodjo stated that referring to the system on Java Island, the company must still carry out retrofits on its power plants. The modification allows power plants to utilise coal with a lower calorific value. Darmawan cited the successful retrofit of the Suralaya 6 and 7 units, which are now capable of using low-calorie coal at around 4,100–4,300 kcal per kg, down from the initial specification of 4,600–4,800 kcal per kg. Following this success, PLN is immediately conducting feasibility studies for projects across all its power plants. Darmawan believes the modifications could be a long-term solution to the problem of medium-rank coal supply. He noted that the production of low-calorie coal is currently much higher than that of medium to high-calorie coal. This supply constraint for medium-calorie coal caused PLN to implement rolling blackouts in mid-June 2026. To address the mismatch between national coal production, which is dominated by low-calorie coal, and the dwindling production of medium and high-calorie coal, the company is retrofitting its generators. For the short term, PLN has received additional supplies of coal with a calorific value above 4,500 kcal per kg, including an extra 1.8 million tonnes in July and approximately 3 million tonnes from August to December from existing sources, ensuring no further blackouts in Java.