What grade of coal does India produce?

• The Gross Calorific Value (GCV), or the amount of heat or energy that can be generated from burning the coal, determines the gradation of coal.

‘High grade’ and ‘Low grade’ coal

• Coal being a fossil fuel is a mixture of carbon, ash, moisture and a host of other impurities.
• The higher the available carbon in a unit of coal, the greater is its quality or ‘grade.’
• There are 17 grades of coal by this metric from grade 1, or top quality coal, with a kilo of it yielding higher than 7,000 kcal, and the lowest producing anywhere between 2,200-2,500 kcal, as per a classification by the Coal Ministry.

Characteristics of Indian coal

• Indian coal has historically been evaluated as being high in ash content and low in calorific value compared to imported coal.
• The average GCV of domestic thermal coal ranges from 3,500-4,000 kcal/kg compared to imported thermal coals of +6,000 kcal/kg of GCV.
• Also the average ash content of Indian coals is more than 40% compared to imported coal which has less than 10% ash content.
• The consequence of this is that high-ash coal when burnt results in higher particulate matter, nitrogen and sulphur dioxide.
• Given this, the government, since 1954, has controlled the price of coal in a way that power companies were disincentive to use high-grade coking coal for power generation.

Clean Coal

• Broadly, we get clean coal when the carbon content has been increased by reducing its ash content.
• Coal plants have ‘washing plants’ on site which can process the coal in ways that reduce ash and moisture content.
• They employ huge blowers or a ‘bath’ to remove fine, coarse ash.
  • However, deploying such equipment is expensive and adds to the cost of power.
• The other method to clean coal again requiring significant investment is coal gasification.
• Here, the need to directly burn coal is bypassed by converting it into gas.
• The resulting syngas, a mixture of carbon monoxide, hydrogen, CO2 and water vapour, is then cleaned and burned in a gas turbine to make electricity.

Future of coal in India

• Official data says that India in 2023-24 produced 997 million tonnes of coal, an 11% growth over the previous year. Most of this was produced by the state-owned Coal India Ltd and its subsidiaries.
• Despite stated commitments to transition India’s electricity sector away from fossil fuel, coal is the mainstay of India’s energy economy.
• Change, however, is in the air as for the first time this year, renewable energy accounted for 71.5% of the record 13.6 GW power generation capacity added by India in the first quarter of this year
• While coal’s share (including lignite) of total power capacity dropped below 50% for the first time since the 1960s.