Deepavali has come and gone and a major episodic source of pollution has blown past. We now have to confront the challenge of poor air quality for the rest of the year. As would be expected, all eyes will now turn to emissions arising from the use of fossil fuels, the most perceptible source universally. From among these, as per the Global Burden of Disease–MAPS study, coal contributes ~15 per cent of the PM 2.5 load in India. Coal-fired power generation accounts for nearly 70 per cent of total coal consumed in the economy. Though India has, for the longest period, relied on (and continues) to rely on coal for power generation, nearly 60 per cent of the coal-based generation capacity was built in the last decade. The young fleet belies the environmental stresses that originate from coal-fired power generation. There are a few reasons for this. The first is that Indian coal burns poorly and generates a significant amount of primary PM 2.5. The second is that newer and tighter emissions standards for SOX and NOX (precursors to secondary PM 2.5), though announced in 2015, are yet to be complied with, by a bulk of the power plants. The third, and most importantly, efficiency of generation is not a criterion that determines which plants are actually generating actively.
High-ash, low calorific value coal, that is predominantly mined in India, means that we are burning more coal to generate every unit of electricity. What little washing of coal that was mandated and existed was done away with in a May 2020 notification. Nearly 30 per cent of the air pollution attributable to power plants are in the form of primary particulate matter that are produced from this ash found in coal. This means, power plants have to operate more expensive and efficient particulate filtration systems to bring emissions down to compliant levels. This also results in more bottom-ash that accumulates at power plants. More than 10 billion tons of unused (unusable) ash can be found in ash-dykes and ponds next to thermal power plants. This pollutes the water and soil in the vicinity of these power plants.