The Central Electricity Authority (CEA) has notified standard implementation timelines for various configurations of inter-state transmission system (ISTS) projects to improve predictability and facilitate coordinated system development.
As per the framework, greenfield substations operating at 765 kV or 400 kV are to be completed within 36 months, while those at 220 kV or 132 kV have been assigned a timeline of 24 months. The implementation period for high-voltage direct current projects, comprising transmission lines and substations, has been fixed at 48-54 months. For transmission lines, the timelines vary with voltage level and line length and range from 24 months to 36 months. Similarly, augmentation works at existing substations are to be completed within 24-30 months, depending on the voltage level and type of substation. The framework also provides flexibility for projects located in hilly and difficult terrains in the North-Eastern region, Sikkim, Jammu & Kashmir, Ladakh and Himachal Pradesh, where an additional six to 12 months may be allowed on a case-to-case basis. Further, in schemes comprising multiple project components, the overall implementation period will generally be determined by the component having the longest timeline, although compressed schedules may be considered in exceptional circumstances.