Tamil Nadu Electricity Regulatory Commission (TNERC) has issued the Tamil Nadu Electricity Grid Code 2026. It has repealed the earlier 2005 grid code and incorporated provisions from the Indian Electricity Grid Code 2023, while embedding state-specific operational requirements.
The grid code lays down procedures to ensure equitable and efficient handling of day-to-day technical operations in the electricity supply system, accounting for a wide range of normal and abnormal operating conditions. Furthermore, the codes are applicable for the state load despatch centre (SLDC), state transmission utility (STU), transmission licensees, distribution licensees, generating companies, open access consumers, and all other users connected to or using the intra-state transmission and distribution systems. Additionally, the SLDC has been assigned the responsibility of overseeing integrated grid operations, supervision, and compliance monitoring.
The SLDC will prioritise the evacuation of available solar and wind power and treat such plants as must-run stations. However, it may direct generators to curtail output to maintain grid security or prevent risks to equipment or personnel, and compliance will be mandatory. Additionally, renewable generators, especially wind and solar plants connected at extra high voltage levels, will be required to comply with reactive power management obligations. According to the code, renewable generators are required to operate voltage control systems and comply with the technical standards prescribed by the Central Electricity Authority.
Furthermore, the code mandates all users to act in coordination to maintain system stability. The rated system frequency is set at 50 Hz, with normal operation to be maintained within the 49.9–50.05 Hz range. The SLDC is mandated to measure frequency with high accuracy and archive data at 1-second intervals.
