Hyderabad: Six years after a hydroelectric power unit was shut down after an accident and several trial runs failed, Telangana Genco has resumed trial runs of unit IV of Srisailam hydroelectric power station at Srisailam. Unit IV generates 150 megawatts (MW) of power. Official sources said the trial runs will continue for some more days before it is put to full use.Telangana Genco chairman and managing director S Harish said Monday’s trial run was successful and more would be conducted. The Srisailam hydropower station has a total of six units, each with a 150-MW capacity and generates about 900 MW of power. Usually, Genco generates hydro power during the monsoon as Srisailam gets huge inflows.All six units of the hydroelectric power plant were damaged in a major fire mishap at the powerhouse in Aug 2020 in which nine people, including engineers and two employees of a private agency died. Since the fire started at Unit IV, it was completely gutted and two units, I and II, got partially damaged. Both I and II units were repaired and power generation was restored within a couple of months, while units III and V were restored in a phased manner.Officials said the crucial unit IV could not be restored as the power plant was established over 20 years ago and some spare parts were not available in the market. “As Covid-19 was sweeping the country and some spares were to be brought from other countries, it did not happen. Voith Hydro Power Ltd has been entrusted with the restoration work of the power generation unit, apart from lamination, transformers and coils took some time. Govt had spent about Rs 200 crore for the restoration of the power unit,” the officials added.Explaining the critical issues in the plan, the Genco officials said that after completion of starter re-winding and rotor re-conditioning works in July 2023, the unit worked for 80 hours and tripped. The second time, contractor Voith Hydro Pvt Ltd agreed to carryout re-winding of the starter free of cost as the guarantee period expired. The second trial run tripped due to an air gap in Oct 2025 due to some technical issues. Govt and agencies consulted HM Hydro, Japan, and resolved the issues.Officials said the hydroelectric project, which was started in the early 2000s, has mostly imported parts from Japan. The fully automated plant generators and controlling system (SCADA) were supplied by Mitsubishi, while turbines, auxiliaries, GIS and 400 KV cables were supplied by Hitachi. Some parts like inlet valves and excitation system were provided by BHEL.
