Fuel management, particularly in thermal power generation, is a crucial aspect of operational efficiency and cost management. For power generation companies (gencos), managing fuel effectively encompasses ensuring the right quantity, quality, price and logistics of coal, alongside managing the ash produced from combustion. Effective ash management is crucial in thermal power generation, especially for environmental sustainability and operational efficiency. The by-products of coal combustion–fly ash and bottom ash–present both challenges and opportunities for power gencos. The effective utilisation of these materials can mitigate environmental impacts, while providing valuable resources for
various industries.
Fuel management
Coal serves as the backbone of thermal power generation, making up 60-70 per cent of the total cost structure for these plants. The reliance on coal underscores its significance, as its availability, quality and price directly influence the efficiency and economic viability of power generation. Its effective management is not merely a logistical concern; it is a strategic necessity. Efficient coal management ensures that power plants operate smoothly, minimising costs, while maximising output. The complexity of coal management lies in the intricacies of its supply chain, which spans mining, transportation and preparation for use. Each stage of this chain has a direct impact on the cost and reliability of power generation, making it imperative for gencos to optimise their coal management processes.
The coal supply chain is a complex process that includes the extraction of coal from mines, its transportation to power plants, and the preparation necessary to make it suitable for combustion. India, as the holder of the fourth largest coal reserves globally, plays a pivotal role in the global coal industry. With 352.13 billion metric tonnes of coal, primarily non-coking, India’s reserves are a crucial resource for its energy needs. Two key players dominate the Indian coal industry – Coal India Limited (CIL) and Singareni Collieries Company Limited (SCCL). CIL, the largest coal producer in the country, accounts for over 80 per cent of India’s total coal production, while SCCL contributes around 12 per cent. The beneficiation and washing of coal are essential processes within the supply chain, as they enhance the quality of coal, making it more efficient for power generation. These processes are vital for adding value to the extracted coal, ensuring that it meets the specific requirements of thermal power plants.
Challenges and solutions in fuel management
One of the primary challenges in fuel management is ensuring the availability of the right quantity of coal to meet the demands of power plants. The balance between supply and demand is delicate, and any disruption can have significant consequences on power generation. To address this, initiatives such as the Scheme for Harnessing and Allocating Koyala (Coal) Transparently in India have been introduced. This scheme aims to stabilise coal supply by providing more predictable allocations through coal mine auctions and backward integration. Such measures not only ensure its consistent supply but also optimise transportation routes, reduce costs and enhance plant efficiency. By improving the coordination between coal production and power generation, these initiatives help mitigate the risk of supply shortfalls.
The quality of coal is a critical factor that directly affects the operational efficiency and costs of power plants. Variability in coal quality can lead to higher operational and maintenance costs, as well as challenges in meeting environmental compliance standards. To ensure that power plants receive coal of the right quality, third-party coal sampling agreements are increasingly being implemented. These agreements help in maintain consistent quality by monitoring key parameters such as calorific value, ash content and coal size. High quality coal minimises operational issues, reduces the need for extensive pollution control measures and lowers the overall cost of power generation.
Pricing is another complex aspect of fuel management, particularly in deregulated markets where coal prices are not standardised. The absence of a unified pricing mechanism leads to significant variability in coal costs, which can impact the economic viability of power generation. The introduction of the National Coal Index is a step towards addressing these challenges by providing a benchmark for coal prices based on market conditions. Additionally, creating comprehensive regulatory frameworks and incorporating the goods and services tax into coal pricing could bring more stability to the market and reduce the overall cost, making power generation more affordable.
Efficient logistics are crucial for ensuring that coal is transported from mines to power plants in a cost-effective and timely manner. Transportation costs represent a significant portion of the overall cost, and optimising these logistics can lead to substantial savings. Rail transport is generally more cost-effective and environmentally friendly compared to road transport, offering significant advantages in terms of energy consumption and carbon emissions. The development of dedicated freight corridors, along with the use of conveyor belts and merry-go-round systems, can further enhance the efficiency of coal logistics. These systems not only reduce transportation costs but also minimise their environmental impact, contributing to more sustainable power generation.
Ash utilisation
Ash management is crucial for maximising the value derived from the by-products of coal combustion, specifically fly ash and bottom ash. During 2021-22, only 32 power stations with generating capacities of 1,000 MW and above achieved 100 per cent ash utilisation. Fly ash, a fine powder by-product of coal combustion, has found extensive applications in multiple industries. One of the most significant uses of fly ash is in the production of cement, where it serves as a partial substitute for Portland cement, enhancing the strength and durability of concrete. This not only reduces the demand for traditional cement but also lowers the carbon footprint associated with cement production. Additionally, fly ash is used to manufacture fly ash bricks, which are more environmentally friendly than conventional clay bricks due to their reduced energy consumption and lower emissions during production. Beyond construction, fly ash has proven beneficial in agricultural applications. When used as a soil conditioner, it improves soil structure, enhances water retention and provides essential nutrients to crops. Fly ash is also employed in the production of various concrete products, such as paver blocks and hollow blocks, further
demonstrating its versatility as a sustainable material.
While fly ash is widely used, bottom ash–coarser and heavier than fly ash–also offers valuable applications. Traditionally, bottom ash has been used for land reclamation and filling abandoned mines, providing a practical solution for managing this by-product. It is also utilised in the construction of embankments and pavements, where its stability and durability contribute to the longevity of infrastructure projects. These uses of bottom ash help reduce the environmental burden of disposal and create value from what would otherwise be considered waste.
In recent years, innovative approaches to ash utilisation have emerged, offering new possibilities for enhancing sustainability in the power generation sector. One such innovation is the production of lypros, a material derived from bottom ash that can serve as a replacement for natural sand in construction. This not only addresses the growing scarcity of natural sand but also offers a more durable and long-lasting alternative for use in mortar and concrete. The development of lypros represents a significant advancement in the sustainable use of bottom ash, contributing to the circular economy by turning waste into valuable resources.
Another promising development is the production of potash-rich organic manure (PROM) from bottom ash, fly ash and other types of eco ash. This organic manure, rich in essential nutrients, has the potential to revolutionise agricultural practices by providing an environmentally friendly alternative to chemical fertilisers. Trials for PROM production are currently under way, highlighting the potential for ash by-products to play a crucial role in sustainable agriculture.
Strategic investments in infrastructure and technology are necessary to drive long-term improvements in ash utilisation. For example, developing dedicated freight corridors for efficient ash transportation can reduce logistical challenges and lower costs associated with ash disposal and utilisation. Investing in advanced technologies for ash processing and utilisation can also enhance the value of ash by-products, making them more attractive to various industries.
Emphasising efficiency and innovation will be key for gencos as they navigate the evolving energy landscape. By focusing on sustainable practices and making strategic investments, gencos can enhance their operational resilience and contribute to a more sustainable future for the power generation sector.
To fully realise the potential of ash utilisation, gencos must adopt integrated approaches that address both current challenges and future opportunities. Advanced technologies adopted in real-time monitoring and quality control of ash can significantly improve the efficiency and effectiveness of ash management practices. By implementing these technologies, gencos can ensure that ash is consistently of high quality
and suitable for various applications, reducing the environmental impact of ash disposal.
Policy reforms are also essential to support sustainable ash utilisation. Active engagement in policy discussions and adherence to regulations related to coal pricing and ash utilisation can help create a more favourable environment for innovative practices. Additionally, the adoption of sustainable practices in fuel and ash management is crucial for reducing the overall environmental impact of thermal power generation. This includes exploring new uses for ash, improving existing utilisation methods and ensuring compliance with environmental regulations.
Conclusion
Fuel and ash management are crucial for the operational success of thermal power gencos. Addressing challenges related to quantity, quality, price and logistics of coal, along with effective ash management, is essential for optimising costs and ensuring sustainable power generation. By embracing policy reforms, technological advancements and strategic investments, gencos can enhance their efficiency and contribute to the broader goals of economic growth and environmental sustainability.
Based on a presentation by Tarun Chattopadhyay, Head, Fuel & Ash Management, Tata Power, at a recent Power Line conference
