India: Portside Indonesian thermal coal prices edge higher w-o-w amid tightening supply signals

• Quota constraints restrict fresh allocations for 4,200 GAR material
• Low power inventories, stronger Chinese buying support demand

Indian portside prices of Indonesian thermal coal increased slightly during the week ended 21 August 2026, supported by emerging supply-side constraints, weather-related disruptions, and signs of improving Chinese buying interest.

Premium 5,000 GAR coal was assessed at around INR 10,500/t at Kandla and INR 10,400/t at Vizag, while 4,200 GAR coal increased by INR 50/t w-o-w to INR 8,750/t at Kandla and INR 8,650/t at Vizag. Meanwhile, 3,400 GAR coal prices at Navlakhi rose by INR 100/t w-o-w to INR 6,950/t.

A market participant indicated, “Indonesian coal availability could tighten further as production work plan or RKAB-related quota constraints continue to restrict fresh allocations for 4,200 GAR material. Several miners are reportedly holding back offers until production quotas are allotted, limiting spot availability. Meanwhile, high-GAR coal remains relatively scarce, providing additional support to premium-grade prices. Weather-related disruptions, including cyclone impacts, could further affect mining and logistics, potentially increasing short-term supply risks.”

Port inventories build amid selective buying

India’s thermal coal inventories at major ports increased 14.3% w-o-w to 13.48 mnt in Week 33, from 11.79 mnt in Week 32, as fresh arrivals exceeded cargo evacuations. The rise indicates a partial rebuilding of imported coal stocks after the previous week’s sharp drawdown. Buyers continued to procure selectively, and inventory accumulation remained concentrated at key ports.

Power sector stocks remain under pressure

Coal stocks at Indian thermal power plants declined by around 6% w-o-w to 33.2 mnt as of 20 August, equivalent to approximately 11 days of consumption. The continued drawdown indicates persistent pressure on domestic coal availability, particularly at vulnerable generating units.

Around 35 power plants reported critical inventory levels, with uneven coal distribution and localised logistics constraints adding to supply concerns. The situation could encourage selective restocking of imported thermal coal, particularly where domestic availability remains constrained.

Global Indonesian benchmarks gain on supply-side concerns

International Indonesian thermal coal benchmarks also strengthened marginally during the week, with prices increasing by approximately $0.5-0.8/t for 5,800 GAR and $0.5-1/t for 4,200 GAR and 3,400 GAR coal. Weather-related supply disruptions and tighter availability provided underlying support, although subdued downstream demand continued to cap the extent of the price gains.

Outlook

The near-term outlook for Indonesian thermal coal prices in India is moderately bullish, with the potential for further modest gains as weather disruptions intensify and Chinese buying remains supportive. However, the upside is likely to remain measured due to selective Indian buying, adequate port inventories and subdued downstream demand. 4,200 GAR and high-GAR grades may witness relatively stronger price support due to constrained availability, while lower-CV grades could remain comparatively stable unless demand improves materially.