Indonesia: Mid-September HBA reflects mixed trends in thermal coal prices

• High-, mid-CV coal prices decline amid loose supply
• Low-CV coal gains modestly, suggesting steady demand

The Indonesian Ministry of Energy and Mineral Resources (ESDM) has published the updated Harga Batubara Acuan (HBA), the benchmark thermal coal price index, for the second half of September 2025.

The latest update indicates a downtrend in higher calorific value (CV) coal, as well as the mid-CV grade, shaped by changing international demand patterns across key importing markets. However, prices of lower-CV grades were raised.

ESDM issued the September 2025 HBA on 12 September 2025, which is effective from 15 September. While released earlier, its validity remains unchanged.

High-CV coal sees minor decline

The benchmark price of high-calorific value (6,322 kcal/kg GAR) coal slipped 1.75% to $103.49/t compared to the first half of September. The modest decline is largely attributed to increased Indonesian thermal coal exports across Asian markets, which added supply pressure and tempered recent price gains.

Mid-CV coal faces steeper correction

Mid-calorific value (5,300 kcal/kg GAR) coal witnessed a sharper drop of 3.16% to $64.4/t, marking its lowest level since March 2025. The decline stems from higher availability in the Asian market, reflecting an oversupply scenario that weighed on market sentiment for mid-grade coal.

Low-CV coal edges higher

Contrasting the trend in higher grades, low-calorific value coal demonstrated relative strength in mid-September. The 4,100 kcal/kg GAR grade edged up by 0.66% to $42.58/t, while the 3,400 kcal/kg GAR rose 1.42% to $32.78/t.

Steady regional demand, particularly from utilities seeking affordable fuel, supported this gain. Its cost-effectiveness makes low-CV coal a stabilising factor amid market volatility.

Rising exports add pressure on high-grade coal

Indonesia’s non-coking coal exports increased 5.5% m-o-m in August, boosting global supply. This surge contributed to the softening of high- and mid-grade coal prices.

Outlook

Coal markets are likely to remain under pressure, with high-CV weakness and mid-CV softness persisting. However, selective demand for low-CV coal may provide some stability amid volatile global trade and shifting procurement strategies.