India's coal import substitution drive reaches its engineering limits

India's push to reduce thermal coal imports is becoming a story about engineering limits, plant economics and fuel quality, rather than just a supply or foreign exchange issue.

For years, India's strategy to increase domestic coal production has delivered strong results. But replacement of imported cargoes wherever possible is happening for the first time on a large scale in 2026, official data shows.

Domestic production has repeatedly hit record highs, coal stockpiles remain comfortable and policymakers are backing the transition with measures ranging from expanded coal linkages and logistics investments to greater fuel allocation flexibility. As the easiest substitutions are made, however, the remaining imports increasingly belong to consumers facing technical rather than supply constraints, sources said.

Coal imports have declined steadily over the past year as end-users turned to lower-cost domestic supplies. Thermal power plants imported around 45.4 million mt of coal in FY 2025-26 (April-March), down about 27% from the previous year, while production during the fiscal year stood at 1.04 billion mt, 0.6% lower from FY25 output, according to government data.

Indian utilities typically import coal ranging from 3,400 kcal/kg GAR to 5,000 kcal/kg GAR for blending with domestic coal, particularly at coastal plants where logistics often favor imported cargoes.

Global coal prices have strengthened due to US-Iran conflicts, which disrupted the natural gas/LNG supply, making coal more attractive than alternative fuels, while higher risk premiums and freight rates increased delivered costs. India-delivered 4,200 kcal/kg GAR coal on the west coast averaged $71.35/mt in the January-June period, up from $56.65/mt in the same period the previous year, data from Platts, S&P Global Energy, showed. The grade was assessed at $83.45/mt on Sept. 1.

Engineering tests take over

Cement producers have been adjusting kiln operations and optimizing fuel mixes across different coal grades, while sponge iron manufacturers have become increasingly adept at modifying feedstock blends, adjusting air-flow systems and fine-tuning operating temperatures to accommodate variations in domestic coal quality, according to sources. Coal washing and beneficiation are also helping reduce ash levels in domestic supplies, narrowing some of the quality gap with imported coal. Such adaptations may not entirely eliminate import requirements, but they significantly expand the range of domestic coal that industrial consumers can use.

A similar trend is emerging in the power sector. Domestic power plants that use imported coal for blending have been cutting down volumes. Latest government data shows four independent power plants used imported coal in June in the range of 5%-32%, while five managed with 100% domestic coal. As coal washing capacity expands and logistics improve, a larger share of industrial and utility demand can potentially shift toward domestic material.

Yet focusing exclusively on falling imports risks missing a more important development. India is moving from the easy phase of import substitution to the difficult one.

Historically, many industrial consumers paid a premium for imported coal because consistency often mattered more than price. Today, digital combustion controls, automated fuel handling systems, and improved coal preparation technologies are reducing that dependence, sources said. As a result, the real question for many industrial users is no longer whether domestic coal can be used, but how much domestic coal can be used before efficiency losses outweigh fuel-cost savings.

Import substitution challenges

Power plants designed to run only on imported coal have been blending 10%-30% domestic coal since early this year, an imported-coal-based plant operator told Platts. "This has led to boiler efficiency challenges, and high ash handling costs, but they are mostly used for high-demand periods," he said.

Roughly 18 GW of generating capacity was originally designed around imported coal specifications, particularly Indonesian sub-bituminous coal and other low-ash, high-calorific-value fuels. Their boilers, milling systems, ash handling infrastructure and overall combustion dynamics were optimized for those characteristics. Although a relatively small portion of India's overall coal-fired fleet, these plants account for a significant share of thermal coal imports and therefore represent one of the final frontiers of import substitution.

Domestic Indian coal typically contains significantly higher ash content, lower calorific value and different combustion behavior. As a result, increasing domestic coal usage is not simply a procurement decision but often an engineering exercise.

Imported-coal-based plants continue to raise concerns around higher maintenance requirements, increased wear and tear, boiler efficiency losses and ash handling costs, a coal trader supplying to an imported-coal-based plant said. "Beyond a certain threshold, each incremental tonne of domestic coal can produce diminishing operational benefits," the trader said.

That is why the future is unlikely to be a binary shift from imported coal to domestic coal. While domestic coal will continue gaining share as transportation infrastructure improves, railway connectivity expands and state-owned miners make supplies available closer to consumption centers, imported coal is likely to retain a strategic role.

Certain power plants will remain structurally dependent on imported fuel because of design limitations. Others may find that a blended fuel strategy delivers the optimal balance between cost, efficiency and operational reliability. Non-power sectors may reduce imports faster yet demand for higher-quality coals unavailable in sufficient quantity domestically is likely to persist.