The Unit one of the Udangudi Supercritical Thermal Power Plant in Thoothukudi district has begun commercial electricity production after it was connected to the power grid, the Tamil Nadu Power Generation Corporation Limited (TNPGCL) said. The new 660 megawatt (MW) unit raised the state coal fired thermal capacity and marginally increased the overall installed power capacity of Tamil Nadu. The commissioning prompted a celebration at the plant campus by TNPGCL officials.

TNPGCL said the unit met the required Commercial Operations Declaration standards and completed the mandatory 72 hour full load trial. The managing director, Govinda Rao, said the countdown for the trial run started at 4.16 pm on September 2 and concluded at 4.16 pm on Saturday, with generation peaking at 709 MW demonstrating the unit's reliability for commercial operations. The connection to the national grid followed regulatory grid code and electricity regulatory commission provisions.

Construction of the Rs 130.77 billion (bn) project began in 2018 and the second unit is expected to be completed by December 2026. Work on the boiler turbine generator, ash disposal unit and natural draft cooling tower is in its final stages according to officials. The plant comprises two units and the first unit underwent an oil based trial run on September 11, 2025 before a coal powered trial began on February 4, 2026.

The complex features a dedicated offshore coal jetty located eight kilometres off the Kallamozhi coast near Udangudi to supply coal. TNPGCL said commercial operation of Unit one increased the state's coal fired thermal power capacity from 5,120 MW to 5,780 MW while the total installed power capacity of Tamil Nadu stood at approximately 42,772.20 MW as of March 2025 and is set to increase to 47,048 MW in the 2026-27 fiscal. The project director, Sethuram, was present when Unit one was connected to the grid.