The Inter State Transmission System (ISTS) in India has been planned to facilitate smooth transfer of power across state and regional boundaries all over the country. In this process, robust National Grid has been established leading to One Nation - One Grid - One Frequency, facilitating power transfer from the resource rich areas to major load centers of the country with reliability and security.

The Cumulative inter-regional power transfer capacity of the National Grid is expected to increase from the present level of 1,00,550 MW to about 1,18,050 MW by 2022.

To fulfill targets of RE capacity (175 GW) by 2022, various initiatives has been taken like Green Energy Corridors Scheme, Transmission for Ultra Mega Solar Power parks, Transmission planning for Renewable Energy Zones (66.5 GW) by 2022, etc.

The transmission losses in Inter-State Transmission System (ISTS) are of the order of 2.5 - 3% which are due to inherent design of the system and technical in nature. High capacity transmission corridors of Extra High Voltage level as well as energy efficient devices are installed to maintain the ISTS losses to minimum level.