The Central Electricity Authority (CEA) has issued standard implementation timelines for interstate transmission system (ISTS) projects to improve predictability and coordination in transmission development.

The timelines were approved by the National Committee on Transmission.

The standardized timelines come amid growing concern over delays in transmission infrastructure.

CEA said generation developers, transmission developers, distribution companies, bulk load consumers, and other stakeholders should consider these timelines while planning generation or load schedules, financial closure, equipment procurement, and related milestones.

The timelines are aimed at aligning project planning with the development of the corresponding transmission system.

Greenfield air-insulated, gas-insulated, or hybrid substations at 765 kV or 400 kV will have a 36-month implementation timeline. Greenfield substations at 220 kV or 132 kV will have a 24-month timeline.

High-voltage direct current systems, including lines and substations, must be completed within 48 to 54 months.

For transmission lines, 765 kV double-circuit lines below 100 km must be implemented within 30 months, and those above 100 km within 36 months.

The timeline for 400 kV double-circuit lines below 50 km has been set at 24 months. Lines above 50 km will have a 30-month timeline.

The implementation timeline for 220 kV or 132 kV lines has been set at 24 months.

Augmentation at existing air-insulated substations of 400 kV and above will have a timeline of 30 months, and those with 220 kV and 230 kV and below must be completed in 24 months.

Augmentation at existing gas-insulated or hybrid substations rated 132 kV and above will have a 30-month timeline.

Projects in hilly or rugged terrain in the Northeastern Region, Sikkim, Jammu and Kashmir, Ladakh, and Himachal Pradesh will have an additional 6 to 12 months for implementation.

For programs involving a combination of different transmission works, the timeline of the activity with the longest implementation period will apply to the entire program.

However, compressed timelines may be considered on a case-by-case basis in cases of exigency.

Mercom recently reported that 36 critical ISTS lines had crossed their commissioning dates, heightening concerns among renewable energy developers facing evacuation constraints and curtailment.

Mercom had earlier reported that renewable energy projects in India have faced delays as transmission infrastructure has lagged behind project commissioning schedules, with right-of-way issues, landholder opposition, litigation, compensation disputes, and forest and wildlife clearances slowing the development of power evacuation infrastructure.