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Despite the resource’s vast polluting potential, coal remains the most dominant source of energy globally, responsible for 37% of global energy generation in 2019. India has also undertaken an initiative to produce 1.2 billion tonnes of coal by 2023-24.

Coal is observed to be the single biggest contributor to anthropogenic climate change, with coal-based electricity being responsible for nearly 30% of global greenhouse gas (GHG) emissions. Despite the resource’s vast polluting potential, coal remains the most dominant source of energy globally, responsible for 37% of global energy generation in 2019. The situation in India is not far from the global reality, wherein coal, while indispensable to the country’s energy security, is responsible for 70% of all fuel-related CO2 emissions in the country. However, despite the tall commitments that India has made in the fight against climate change, it has also undertaken an initiative to produce 1.2 billion tonnes of coal by 2023-24, underlining India’s intentions to continue substantial use of this resource. If India is to adhere to the commitments it has made in the global struggle against climate change, while persisting with its use of coal, it is paramount that methods to decarbonise this vital resource be investigated.

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.

Source:https://www.hindustantimes.com/ht-insight/economy/the-future-of-coal-in-india-decarbonising-the-oft-maligned-resource-101675679259226.html