Operations and maintenance (O&M) services play a critical role in ensuring the sustained performance, reliability and efficiency of thermal power plants (TPPs). Robust O&M strategies not only help maintain high operational standards but also extend the asset life and improve cost competitiveness. Efficient O&M practices enable plants to optimise performance, reduce emissions, minimise downtime and mitigate operational risks. However, with a significant share of the thermal fleet ageing, maintaining operational efficiency has become increasingly challenging. Older plants tend to experience performance degradation, higher heat rates and more frequent breakdowns, requiring enhanced maintenance practices, stricter adherence to environmental norms, efficient coal ash management and optimised water usage.
TPP operations are also undergoing a significant transformation due to the increasing penetration of renewable energy. Unlike earlier baseload operations, many thermal plants are now required to operate in a flexible manner, involving frequent ramp-ups and ramp-downs. This cyclic operation deviates from their original design parameters, causing additional mechanical stress, accelerated wear and tear and changes in performance characteristics. As a result, there is a growing need for O&M strategies that are tailored to the plant’s age, design complexity and economic viability. While conventional maintenance approaches such as reactive, preventive, condition-based and predictive maintenance have been widely adopted, there is now a clear shift towards more integrated and lifecycle-based strategies, particularly reliability-centred maintenance (RCM).
Best O&M practices
Preventive maintenance remains a cornerstone of effective O&M management. Through routine inspections and scheduled servicing, potential faults can be identified and addressed before they escalate into major failures. Activities such as the lubrication of moving components, cleaning of filters and calibration of instruments help ensure that equipment operates efficiently and reliably. Preventive maintenance reduces the likelihood of unplanned outages, lowers repair costs and enhances overall plant availability. It also supports the early detection of equipment degradation, enabling timely replacement or refurbishment and preventing cascading failures across systems.
In recent years, many utilities have increasingly adopted RCM as a more comprehensive and strategic approach to O&M. RCM focuses on balancing risk and cost to determine the most effective maintenance strategy for each asset. It integrates various maintenance methodologies – including preventive, predictive, real-time monitoring and reactive maintenance – into a unified framework. The primary objective of RCM is to ensure that equipment performs its intended function reliably while minimising lifecycle costs. Unlike traditional approaches that may prioritise availability alone, RCM places greater emphasis on reliability and proactive failure prevention. By leveraging real-time data and advanced analytics, RCM systems can identify early warning signs of equipment deterioration and trigger alerts when predefined thresholds are breached. This enables plant operators to take corrective action well before a failure occurs, thereby improving reliability and reducing downtime.
Asset management is another critical dimension of O&M, aimed at maximising the value derived from power generation assets over their entire lifecycle. Effective asset management involves systematic planning, monitoring and optimisation of plant resources to ensure efficient utilisation, cost control and regulatory compliance. It relies heavily on the integration of data from multiple sources, including maintenance logs, operational performance indicators and financial records. By analysing this data, plant operators can make informed decisions regarding maintenance scheduling, asset utilisation and capital investments. A data-driven asset management approach not only enhances operational efficiency but also helps extend equipment life, improve reliability and support long-term planning.
Fly ash and water management
The high ash content of Indian coal results in significant fly ash generation, which, if not properly handled, can cause air and water pollution and pose health risks. Hence, its scientific disposal and utilisation are essential. Fly ash can be effectively used in the construction sector for manufacturing bricks, cement, concrete and tiles, as well as in infrastructure projects such as roads, embankments and mine filling. It also finds applications in land reclamation and agricultural development.
Coal-based TPPs are among the largest consumers of industrial water, with most of the demand arising from cooling systems. Improving water efficiency is therefore critical. Technologies such as air-cooled condensers help reduce dependence on water by using dry cooling methods, making them suitable for water-scarce regions. Enhancing the cycles of concentration further reduces freshwater requirements by minimising blowdown losses. In addition, TPPs are increasingly adopting zero liquid discharge systems, which treat and recycle wastewater, enabling its reuse within the plant and significantly reducing overall water consumption.
Digitalisation of TPPs
The digitalisation of O&M is playing a key role in improving TPP performance. Technologies such as IoT, smart sensors and real-time monitoring enable the continuous tracking of equipment health. Data from boilers, turbines and auxiliaries is analysed using AI and ML to detect faults, predict failures and optimise maintenance, reducing outages and extending asset life.
Digital twins further enhance operations through the simulation of different scenarios and performance optimisation. Integrated asset management platforms streamline maintenance, inventory and workforce planning, improving overall efficiency and decision-making. Drones and robotic tools are being increasingly used for inspecting difficult or hazardous areas, improving safety and accuracy. However, greater digitalisation also raises cybersecurity concerns, making robust protection systems essential for safeguarding critical infrastructure.
Flexibilisation
The rising share of renewable energy in India has made flexibilisation essential for the O&M of TPPs. Designed for baseload operation, these plants must now operate dynamically, ramping output up and down to balance variable solar and wind generation. This shift affects plant performance, asset life and maintenance practices. Flexibilisation involves operating at lower loads, higher ramp rates and frequent start-stop cycles. While this supports grid stability, it increases thermal stress on equipment such as boilers and turbines, raising the risk of wear and failure. Therefore, O&M practices must adapt to maintain reliability.
Enhanced monitoring and diagnostics are critical in this context. Advanced tools such as real-time condition monitoring and predictive maintenance help identify early signs of stress, reduce outages and optimise maintenance schedules. Equipment modifications are also necessary, including boiler and turbine upgrades and improved control systems for smoother and more efficient operations. Flexible operations further complicate water and fuel management, requiring tighter controls to maintain efficiency and prevent damage. Further, workforce training is vital for operators to handle dynamic conditions using data-driven approaches. Despite higher O&M costs due to increased wear and tear, flexibilisation improves grid reliability, supports renewable integration and ensures the continued relevance of TPPs in the evolving energy landscape.
Issues and challenges
Despite advancements, TPPs face several challenges in O&M and asset management. A key issue is ageing infrastructure, with many plants operating for over two decades, leading to higher maintenance needs, lower efficiency and increased costs. Upgrading such assets requires significant investment and planning. Environmental compliance adds further pressure, as stricter emission norms require technologies like flue gas desulphurisation, increasing both complexity and costs. Flexibilisation also complicates operations, as frequent cycling results in greater equipment stress, higher maintenance requirements and reduced efficiency, requiring more adaptive O&M approaches.
Fuel-related issues, including inconsistent coal quality and supply disruptions, affect performance and increase wear and tear, while price fluctuations add cost uncertainty. Meanwhile, growing digitalisation brings challenges in data management and cybersecurity, requiring advanced analytics and robust protection systems. Further, skilled manpower shortages and financial constraints limit the adoption of modern O&M practices, highlighting the need for capacity building and increased investment in technology and infrastructure upgrades.
Conclusion
Effective O&M and asset management are crucial for ensuring the long-term sustainability, reliability and competitiveness of TPPs. As the sector navigates challenges such as ageing infrastructure, stricter environmental regulations and the growing need for operational flexibility, traditional maintenance approaches are proving inadequate. The transition towards reliability-centred maintenance, supported by digital technologies and data-driven asset management systems, is a viable pathway to enhance performance, reduce costs and extend asset life. However, to fully realise these benefits, it is essential to address challenges related to environmental compliance, fuel management, workforce training, cybersecurity and financial constraints. A holistic and forward-looking approach to O&M will be key to maintaining the relevance of thermal power in an increasingly dynamic and decarbonised energy landscape.
