R&M of existing old coal power plants, which can help revive India´s lagging power sector efficiencies, is a huge opportunity waiting to be taken.
A large number of coal-fired power plants were set up in India in 1972, and after over 42 years of being in operation, these plants are at the end of their life-cycles. Some of these old units have already crossed or are nearing their economic life of 25 years and have high specific fuel consumption. As such renovation and modernisation (R&M) of such units provides a good opportunity for capacity upgrade, extended period of operation with limited supply of coal, and can potentially enhance their rated capacity. This leaves no doubt that the market potential here is huge and would definitely attract a lot of investors if policies and priorities can be defined appropriately
R&M is a cost-effective way of increasing the nation´s power capacity. In view of high investment required for green field power stations, resource constraints and environmental concerns, there is an immediate need for optimal utilisation of existing generating capacity. In this context, R&M and Life Extension (LE) of existing old power plants can be considered as the most feasible option. The main objective of R&M of thermal generating units is to make the operating units, well equipped with modified/augmented latest technology equipment and systems. These operations are carried out with a view to improve their performance in terms of output, reliability and availability along with ease of maintenance, reduction in maintenance requirements, and minimising inefficiencies.
In perspective of the Indian power sector, adoption of R&M practices is immensely important. Despite significant growth in generation capacity over the years, the shortage of power continues to persist due to increased per capita consumption in last few decades. Ever increasing requirement of power, reduction in plant load factor (PLF) from 78.6 per cent to 65.4 per cent for the period between 2007-2013, depleting natural resources and environmental concerns have led to an immediate need to undertake measures to enhance performance, longevity of existing infrastructure and cost effective operation of existing thermal power plants. The most convenient and cost effective method to mitigate this, is to carry out an appropriate R&M for the existing and old generation infrastructure with an aim to improve efficiency, life extension and cost effectiveness of the plant.
A successful R&M program can increase rated capacity of plant by 4-8 per cent and efficiency by 8-10 per cent. It also helps to achieve lower secondary oil consumption through reduction in number of trippings, faster start-up and stable combustion at even lower levels of load. Improvement in energy efficiency results in less fuel consumption and reducing CO2 emission. As a result, the auxiliary power consumption is also reduced in a significant way which further reduces the overall carbon footprint of power station.
A typical R&M program initially involves several studies like Residual Life Assessment (RLA) study, Condition Assessment (CA), Performance Evaluation Test (PET), Non-destructive testing (NDT) and energy study to understand and define appropriate engineering solution which may vary case to case depending on age, type and condition of the old power plant. A key challenge is the limitation of agencies with the right core competence and project management skills for R&M implementation in the country.
Author: Shatanshu Shekhar,
Senior General Manager - Industry Services, T_V S_D South Asia