Indian Power System is divided into five regions - Northern Region, Southern Region, Eastern Region, Western Region and North Eastern Region (NER). The inter-regional (IR) transmission links between regions enable smooth flow of power from surplus regions to deficit regions.

At present all the five regional grids are interconnected through synchronous links forming one Nation, one Grid, one frequency, one market.

Inter-Regional Power Capacity

The inter-regional power transmission capacity of the National Grid is 99,050 MW (as on March 2019).

Power Transmission System in India

The transmission systems that are in place in the country consist of Inter-State Transmission System (ISTS) and Intra State Transmission System (IntraSTS).

Since January 2011, ISTS transmission schemes, are being implemented either through the Tariff based Competitive Bidding (TBCB) process or under cost-plus mechanism with Regulated Tariff Mechanism (RTM), in accordance with provisions of the Tariff Policy. Accordingly, the ISTS are developed either by POWERGRID or by the successful bidder in case of TBCB projects. POWERGRID also participates as bidder for TBCB projects.

The Intra-State Transmission System is generally developed by State Transmission Utilities or Intra-state transmission licensees in a State.