Chennai: With electricity consumption in the state rising rapidly and peak power demand scaling new highs every year, the state govt has shifted its focus to improving the efficiency of existing hydropower projects through renovation and upgradation and expanding battery energy storage to strengthen grid reliability and reduce reliance on thermal power.For 2026-27, Tamil Nadu Green Energy Corporation Limited (TNGECL) has set a hydro generation target of 4,776 million units (MU), fixed by the Central Electricity Authority, and plans to maintain the average availability of hydro stations at more than 80 per cent, according to the energy dept’s policy note for the year. TNGECL’s hydro wing now operates and maintains 47 hydro power stations with 107 machines and a total installed capacity of 2,325.90 MW across Erode, Kadamparai, Kundah and Tirunelveli. Most of the stations are located in forest and hilly regions.As several hydro stations in the state are at least 35 years old, TNGECL is undertaking renovation, modernisation and uprating (RMU) works to improve their generation capability. “At Moyar Power House, RMU work on Unit-3 is under way to increase its capacity from 12MW to 14MW. The work is expected to be completed by Nov 2026, adding 2 MW to the grid,” said an official.Similarly, RMU work at Kodayar Power House-I is expected to increase capacity from 60 MW to 70 MW, adding 10 MW to the grid during 2026-27. At Moyar, replacement of three high-pressure penstocks is under way and is expected to be completed for all three units by Sept 2027.At the 400 (4×100) MW Kadamparai Power House, refurbishment of the stator core and complete re-insulation of stator coils in Unit-I is expected to be completed by March 2027, while generator refurbishment in Unit-III is expected to be completed by Feb 2027. Alongside hydro projects, the govt is expanding energy storage capacity to facilitate the integration of increasing amounts of renewable energy into the grid. Electricity and law minister C T R Nirmal Kumar told the Assembly on Friday that Tamil Nadu had set energy storage targets up to 2029-30 in line with Union govt guidelines.TNGECL has initiated the establishment of 1,000 MWh (500 MW for two hours) of standalone Battery Energy Storage Systems (BESS) under the State Component of Viability Gap Funding. Six installations are planned at TANTRANSCO substations in Thennampatty, Anuppankulam, Ottapidaram, Vellalaviduthi, Kayathar and Karaikudi, with commissioning targeted by Dec 2026.Another 1,500 MWh (375 MW for four hours) of standalone BESS is being implemented with financial support from the Power System Development Fund. Eleven TANTRANSCO substations have been identified for these projects, which are scheduled for commissioning by Sept 2027.
