Renovation and modernisation (R&M) of hydroelectric projects (HEPs) is a cost-effective way to deal with technological obsolescence. It restores lost capacity and improves the availability, performance, reliability and efficiency of the plant. It also helps in achieving these objectives with fewer statutory and land clearance requirements, and rehabilitation and resettlement issues, as against setting up new projects. Moreover, the estimated cost per MW of R&M for life extension is much lower than that of new hydro projects of similar capacity.
Under the Central Electricity Authority’s (CEA) R&M programme, during the Twelfth Plan period of 2012-17, around 21 projects (two central and 19 state) aggregating 4,149 MW were taken up for R&M, yielding a cumulative benefit of 549 MW. Overall, R&M works at 104 hydropower projects with an aggregate installed capacity of 20,611 MW were completed by the end of the Twelfth Plan period (in 2016-17) and a total benefit of 3,636 MW, through life extension, uprating and restoration, was accrued. Of these, 21 plants belong to the centre and the remaining 83 to various states.
During 2017-22, renovation, modernisation, uprating and life extension works at 22 HEPs with an aggregate capacity of 4,847.8 MW are planned for completion. This includes R&M of 12 HEPs aggregating 3,729.60 MW, life extension of seven HEPs aggregating 433.2 MW and life extension and uprating of three HEPs aggregating 685 MW. At these three HEPs, the aggregate capacity shall be uprated to 801.2 MW, resulting in an additional benefit of 116.2 MW. As such, the revised aggregate capacity after R&M, uprating and life extension (RMU&LE) works at these 22 projects will be 4,964 MW. Out of these 22 schemes, 12, with an aggregate installed capacity of about 1,938.2 MW, have been completed as of September, 2021, including R&M of 1,544 MW, life extension of 310.2 MW and life extension and uprating of 84 MW. During 2022-27, RMU&LE works at 57 HEPs with an aggregate capacity of 9016.3 MW are planned for completion – R&M of 10 HEPs aggregating 1,723.35 MW, life extension of 39 HEPs aggregating 6,717.95 MW, and life extension and uprating of eight HEPs aggregating 575 MW. At these eight HEPs, the aggregate capacity shall be uprated to 637.5 MW, resulting in an additional benefit of 62.5 MW. As such, the revised aggregate capacity after RMU&LE works at these 57 projects will be 9,078.80 MW.
Challenges and future outlook
Power plant developers face multiple challenges when undertaking RMU&LE works. One of them is the lack of proper policies and guidelines, which often leads to utilities not carrying out these activities. Therefore, the planning of detailed project reports is not given due importance by utilities, resulting in difficulties during the bid stage and delays in R&M works. More often than not, utilities want to undertake piecemeal interventions rather than comprehensive R&M work. The rehabilitation of a hydropower plant is usually performed towards the end of its useful life, that is, after 30-35 years. However, as per industry observers, given that hydro plants are subject to silt erosion (especially in the Himalayan region), which results in forced outages, R&M works need to be taken up much earlier than 35 years. Therefore, various measures are needed to address these issues.
In addition, the lack of experienced contractors and consultancy firms hinders the implementation of such works. As a result, contracts for R&M work are often awarded to incompetent agencies, resulting in a significant delay in project completion and poor quality work. Overall, R&M requires technical, commercial and regulatory support. The technical aspects of hydro plant R&M include an in-depth assessment of the residual life, finalisation of the scope and a detailed report on the specific parts that need attention and refurbishment, in order to enhance the productivity of the plant. Proper financial support, timely tie-ups with the concerned agencies, and timely approvals and clearances from the concerned authorities are imperative.
To conclude, RMU&LE plays a critical role in the operation of hydro plants, and proper planning is needed to identify plants in need of renovation. To achieve the desired results, R&M schemes need to be identified by utilities at the right time for the right projects, so that appropriate programmes can be developed and R&M can be adopted as a one-time approach and not as a substitute for regular maintenance of hydropower