CEA issues standard timelines for ISTS project implementation

The Central Electricity Authority (CEA) has issued standardised implementation timelines for Inter-State Transmission System (ISTS) projects to improve predictability and coordination in transmission system development.

The timelines were approved during the latest meeting of the National Committee on Transmission (NCT). According to the CEA, the framework is intended to support better planning and synchronisation of transmission infrastructure with generation projects and load growth.

Approved timelines

The approved implementation timeline for greenfield 765 kV and 400 kV substations is 36 months, while greenfield 220 kV and 132 kV substations have been assigned a timeline of 24 months.

For High Voltage Direct Current (HVDC) systems, including transmission lines and substations, the implementation period has been fixed at 48–54 months.

For 765 kV double-circuit transmission lines, projects with line lengths below 100 km will have a timeline of 30 months, while those exceeding 100 km will have a timeline of 36 months.

For 400 kV double-circuit transmission lines, projects below 50 km will have a timeline of 24 months, while those above 50 km will have a timeline of 30 months.

The implementation timeline for augmentation works at existing Air Insulated Switchgear (AIS) substations of 400 kV and above has been set at 30 months. For substations of 220 kV and below, the timeline has been fixed at 24 months.

Special provisions

CEA stated that projects located in hilly or difficult terrain in the Northeastern region, Sikkim, Jammu & Kashmir, Ladakh, and Himachal Pradesh may receive an additional 6–12 months on a merit basis.

For composite transmission schemes involving multiple components, the implementation timeline will be determined by the activity with the longest duration. However, compressed schedules may be considered on a case-by-case basis.

Planning guidance

CEA has advised generation developers, transmission developers, distribution companies (DISCOMs), and bulk consumers to incorporate these timelines into project planning activities, including financial closure and equipment procurement, to improve alignment with transmission system readiness.

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