The future of coal in India: Decarbonising the oft-maligned resource

An important parameter that must be analysed to pinpoint the cause of GHG emissions from a country’s coal sector, is the efficiency with which its thermal power plants (TPPs) produce power from coal. The lower the efficiency of a plant, higher is the amount of coal needed to produce the same amount of energy, while also causing a greater amount of GHG emissions, as also those of other pollutants like mercury and lead.

India has registered significant progress in augmenting the efficiency of its coal-fired power fleet, from 32% in 2014 (the then worst in the world) to 37.2% (closer to the global average of 37.7%) in 2016. However, despite the rapid development, which is a likely consequence of significant supercritical (SC) capacity being installed, as well as the retirement of old inefficient plants, India’s coal fleet still has the second highest specific CO2 emissions in the world. As a result, India’s efficiency shades in comparison to global leaders like Japan (43%), who can produce power much more efficiently from coal, and consequently curb emissions.

The primary cause of India’s low efficiency is the significant cohort of older TPPs it is home to, with around 33 GW (16%) of India’s coal-fired power capacity being housed in plants that are 25 years or older. A 2020 study found that the efficiency of close to 60% of this older cohort of India’s coal power capacity is 33% or lesser, helping identify one of the foremost causes of the low efficiency of coal-based power in India.

While the age of India’s TPPs is a significant factor tugging down on the country’s overall efficiency, an equally important role is essayed by the large share of subcritical TPPs in the overall mix. SC and ultra-supercritical (USC) plants are able to operate at higher temperatures and pressures, and produce energy from coal more efficiently than subcritical ones, thereby causing a lesser amount of GHG emissions.

Nearly 3/4th of India’s coal-fired power capacity is subcritical in nature, while only 1% of plants are USC, pointing to another significant factor that is pulling down on the country’s overall efficiency. In comparison, nearly 19% of the TPPs in Japan are USC in nature, which has helped raise the efficiency of Japan’s coal fleet to 43%, the highest in the world. It is indicative of the improvements in efficiency, and the consequent limiting of emissions, that is possible through the adding of SC and USC capacity.

While it is paramount to augment the efficiency of a country’s coal fleet through improving the share of SC and USC plants, it is a method that is expensive and long drawn. It is important that quicker, more inexpensive solutions are looked into.

One of the more immediate instruments that India has at its disposal to reduce coal-based emissions is known as ‘biomass co-firing’, which involves burning a stipulated percentage of biomass along with coal to reduce the GHG emissions resultant from the latter. Biomass co-firing has been identified as one of the most economical ways to reduce GHG emissions from coal-fired power.

In February 2022, India’s finance minister (FM) announced in her budget speech that biomass co-firing at the rate of 5-10% has been mandated for every TPP in the country, the implementation of which can offset 38 million tonnes of CO2 emissions, as per the Minister. While the mandate is well-intentioned, the primary problem that the TPPs across the country face is the lack of a steady supply of biomass pellets to TPPs. The pellet manufacturing industry possesses the capacity to produce only around 7000 tonnes of biomass pellets per day, falling woefully short of the 95000-96000 tonnes that are needed to fulfil this decree. India must strive to develop its biomass cofiring capacities, in order to have an economical method to curb emissions from coal.

‘Coal beneficiation’, which refers to the washing of coal to reduce its ash content, is another method that can be employed by India to reduce GHG emissions from coal. While setting up of coal washeries is expensive for TPPs, it can make a dent in the GHG emissions resulting from coal-fired power, evident from the fact that the use of 34% ashed coal as opposed to 42% ashed coal can result in a 2-3% reduction in CO2 emissions. In India, only 20% of the coal is washed, in contrast to a global average of 50%, underlining the significant scope of improvement that prevails in this area.

The above methods comprise some of the most immediate steps that can be taken to reduce the CO2 footprints of India’s coal sector. However, in order to achieve deep cuts in GHG emissions from coal-based power, India must accelerate the development of technologies like ‘Carbon Capture Utilisation and Storage (CCUS)’, which although remains at a nascent stage in the country, is capable of delivering 80-90% reduction in CO2 emissions from energy-intensive industries. India is part of a global clean-energy consortium of 24 countries, as well as the EU, called the ‘Mission Innovation’ (MI). The Mission focuses on peer learning among nations to achieve the development of affordable and accessible clean energy for all, which includes enabling near-zero CO2 emissions from power plants and carbon-intensive industries through Carbon Capture, a stated objective of the Mission. India can imbibe leading practices in the employment of CCUS through being part of such a consortium, as other countries like Japan and Australia, as well as the EU, have commissioned numerous projects that involve this technology.

Amid increasing pressure over the use of coal from international quarters, the development of coal-based power, especially in the context of reducing emissions from it, stands at a critical juncture in the country. India is striving hard to be a global leader in the area of climate change mitigation, and must lead by example if it is to adorn a place among countries that are spearheading the charge most effectively.

This article is authored by Jay Hajare, research intern at the Centre for Public Policy Research.