Pro-activeness of states and power plants towards handling and utilising its generated fly ash can play a major role in clearing huge ash back logs and enhancing its utilisation
The years 2019 and 2020 witnessed a surge in ash dyke breach incidents from coal power plants across various states in India. This year, major ash dyke breach incidents were reported from the North Chennai Power Station in Tamil Nadu, Sasan Power Plant in Madhya Pradesh and NTPC Talcher in Odisha.
In 2019, major incidents of ash breach occurred at NTPC Vindhyachal and Essar Power Plant in Madhya Pradesh, Bokaro Power Plant in Jharkhand and Khaparkheda and Koradi power plant in Maharashtra. Several legal cases have been pending against power plants due to such breach incidents.
Despite a well-defined policy and regulatory framework in place for 100 per cent fly ash utilisation, more than 50 per cent of power plants are still in non-compliance of this notification. These power plants are majorly concentrated in states like Chhattisgarh, Maharashtra, Madhya Pradesh, Odisha and Uttar Pradesh.
Substantial quantities of coal are consumed in these states, generating huge quantities of ash. Fly ash generation is seen to have almost doubled within a decade in these states. These states, with high amounts of accumulated ash, require immediate attention as these are the regions that have reported frequent incidents of ash dyke breach and also severe air pollution issues.
Though ash generation has increased tremendously due to huge coal capacity addition, it is seen that its utilisation has not been able to keep up in these states leading to its pile-up.
Across Indian states, there is huge variation observed in the fly ash utilisation rate. It ranges from as low as 35 per cent in one state to as high as 98 per cent in another state.
States with good utilisation rate are able to clear their ash stocks. However, states with a low utilisation rate are facing the brunt of pollution due to huge quantities of accumulated ash stocks.
Ash is piling up in the wet form as slurry in ash ponds and in the dry form in open fields in such states. Currently, nearly 1.6 billion tonnes of ash is lying in ash ponds across the country.
Delhi-based non-profit Centre for Science and Environment (CSE), in its recent report on fly-ash, analysed the Central Electricity Authority’s state-wise data on ash generation and utilisation from 2010–11 to 2018–19.
It found that Chhattisgarh and Uttar Pradesh had accumulated the most ash during this period. Madhya Pradesh, Andhra Pradesh, Maharashtra and Odisha also have a huge ash backlog.
Together, these states accounted for 76 per cent of the total residual ash stock left unutilised from the coal power sector between the years 2010 and 2019. Many of the plants with poor ash utilisation rates in these states belong to Centre- and state-owned companies. West Bengal is observed to be the only state that produces a sizeable quantity of ash but manages to clear its stock.
State-wise total unused / residual ash from coal power sector accumulated in the year 2010-11 to 2018-19
|State||Total ash generation
|Total ash utilization
|Ash utilization percentage
|Total residual ash
Source: CSE analysis; data sourced from CEA’s annual ash reports (2010-11 to 2018-19)
Ash utilisation is observed to be low in some regions either due to scarcity of cement or brick manufacturing units in the nearby areas, low demand in construction activities including roads and highways or overabundance of fly ash in the area due to presence of multiple thermal power stations.
Pro-activeness of power plants in clearing their ash and towards handling this issue on a priority basis also plays a major role in enhancing utilisation. Efficient rail / road connectivity in the state to transfer fly ash to distant locations is another important aspect.
The use of fly ash in cement and concrete is one of the most promising. On an average, about 25 per cent of fly ash from power plants in India is currently utilised in cement manufacturing, seven per cent in brick manufacturing and only 3.6 per cent in roads and flyovers.
Andhra Pradesh, Haryana, Karnataka, Punjab, Rajasthan and Tamil Nadu together account for about 60 per cent of the total cement production capacity in India. These are also the states with the highest ash utilisation percentages. On the other hand, in states with poor ash utilisation rates, demand for ash is limited due to minimal presence of such businesses.
Where can fly ash be used
Therefore, states with a huge ash backlog need to explore possibilities of its utilisation on a war footing. Power plants located in these states must also take proactive measures to enhance utilisation.
This can be done by way of entering into long term / medium term / short term contracts with cement / brick manufacturing units or construction agencies located in distant locations that can utilise ash.
Pond ash can be supplied to the National Highway Authority of India, road projects and other government infrastructure projects. Fly ash can be transported in bulk on a regular basis to such units / agencies through roads or cheaper rail network.
Power plants can also explore the possibilities of setting up cement / brick units in its close proximity. Also, state governments must encourage start-ups that can set up businesses in close proximity to power plants by way of providing incentives to them in some form.
The use of fly ash in backfilling of abandoned, open cast and underground mines also has significant potential, especially in case of pithead thermal power stations that otherwise have limited avenues for fly ash utilisation due to their remote location.
Approximately 40 per cent of fly ash on an average remains unutilised every year, which gets dumped in ash ponds. Though its utilisation so far is mostly in the cement sector, the uptake has not been much by the sector when compared to the tremendous growth it has witnessed over the years.
Between 2009 and 2019, cement production in India increased to 334 million tonnes, from 187 million tonnes, an increase of almost 78 per cent. This is expected to reach 400 million tonnes by 2025, owing to continuously rising demand.
Similarly, road networks are expanding in India. New roads, highways and flyovers are coming up and existing ones are being widened. Currently, fly ash use in roads and flyovers is a mere 3.6 per cent and can definitely be enhanced.
To enhance utilisation, a few state governments have also started providing incentives to fly ash start-ups, made use of fly ash bricks compulsory in construction near coal power plants and have mandated use of fly ash bricks in the construction of government buildings.
However, a stricter monitoring regime is required at the state level, in order to keep a check on whether the guidelines on mandatory use of fly ash are being adhered to or not.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.