HPP Sholayar, India

In July 2015, ANDRITZ Hydro signed a contract for the renovation, modernization, and upgrade of the Sholayar hydropower plant, located on the Sholayar River in Tamil Nadu, India. The project on behalf of Tamil Nadu State Generation & Distribution Corporation Ltd. (TANGEDCO) – a utility owned by the state government –comprises two powerhouses; Stage I with 2 x 42 MW and Stage II with 1 x 25 MW.

The equipment for the Stage I powerhouse was originally commissioned in 1971. ANDRITZ Hydro scope of contract includes the electro-mechanical equipment for both units for Stage I powerhouse, including design, CFD analysis, engineering, manufacturing, delivery, erection, testing, and commissioning as well as the supply of new turbines, generators, runners, automation panels, and certain balance of plant equipment. After uprating, the plant capacity has been increased from 70 MW (2 × 35 MW) to 84 MW (2 × 42 MW) representing an overall output increase by 20%.

The project execution was very a challenging task. The hydropower plant is located deep inside a forest reserve area, which is hard to access via narrow and winding roads in bad condition. Legal restrictions made alterations to the road nearly impossible. Transporting the goods to the site was therefore an interesting task requiring a capable crew and top tier equipment. The outside work on the penstocks and upstream and downstream waterways was demanding due to the dangerous fauna and difficult environmental circumstances. The remote location made a daily back and forth travelling of the installation crew necessary, limiting thus the working hours.

The main scope of our work was the replacement of turbines, generators, as well as electrical and mechanical auxiliaries. The reverse engineering had to be completed within six months, the supply of U1 within 12 months, and erection and commissioning within 12 months for each unit. Due to a delay of the LoC the execution period of the whole project was extended by nine months. The whole project took 53 months from handing over of the first unit for reverse engineering until commissioning.

Despite all circumstances, ANDRITZ completed the reverse engineering within only three months, three month prior as per contract; project commissioning was also completed early. In the end, both units were renovated and uprated six months ahead of schedule, making the additional power generation of Sholayar earlier available to the customer. The customer TANGEDECO is very satisfied with the performance of the units.