A major interregional transmission scheme has recently been approved for development under three packages, using a combination of TBCB and RTM modalities.
Expected to cost around Rs.7,250 crore, the composite scheme seeks to improve the interregional transfer between the Eastern Region (ER) and Western Region (WR) grids, and will have an overall completion target of March 2029.
The overarching scheme, termed as “WR-ER Inter-regional network expansion” will have three components – Part A, Part B and Part C.
While Part A and Part C will be developed under the tariff-based competitive bidding (TBCB) framework, Part B – the smallest constituent – will follow the regulated tariff mechanism (RTM) philosophy.
REC Power Development & Consultancy Ltd (RECPDL), as the bid process coordinator, will conduct the tariff-based bidder selection process for Part A and Part C, while Part B has been assigned to “Purulia & Kharagpur Transmission Company Ltd,” a subsidiary of IndiGrid.
Objective
The overall objective of the scheme is to mitigate critical loading on the WR-ER transmission corridors under the peak solar scenario projected for 2028-29. It will also help evacuation of upcoming thermal power projects in the Chhattisgarh (Western Regional Grid).
Transmission elements
Part A, the biggest component with an estimated outlay of Rs.6,272 crore and a completion timeframe of 24 months from SPV transfer date, mainly entails putting up a new 2×1500 MVA, 765/400kV substation at Jamshedpur in Jharkhand (Eastern Region), and a 3×1500 MVA, 765/400kV substation in Chhattisgarh, to be known as “Raigarh (Kotra-II) substation.” Part A will also interconnect the 765/400kV Raigarh (Tamnar) substation in Chhattisgarh via a 315-km double-circuit line to the Jamshedpur substation. There will also be interconnections with other substations including Jeerat (West Bengal), Dharamjaigarh (Chhattisgarh), etc.
Part C, a relatively small component with outlay of Rs.913 crore, will entail connecting the new Jamshedpur substation, coming up under Part A, to the Balasore substation in Odisha, via a 400kV double-circuit (quad) line running about 174 km. Completion of Part C will be aligned to that of Part A.
Purulia & Kharagpur Transmission Company Ltd (PKTCL), the developer of Part B, was originally a wholly-owned subsidiary of Sterlite Power (now Resonia Ltd) that commissioned the ISTS-TBCB scheme “Eastern Region System Strengthening Scheme – VII” in January 2017. PKTCL was eventually acquired by IndiGrid Infrastructure Trust (IndiGrid).
ER-WR transfer
As of August 31, 2025, the interregional transfer capacity between ER and WR was 22,790 MW. The most recent addition in ER-WR transfer capacity, at 1,600 MW, came about in June 2025 through an ISTS-TBCB scheme “Interregional ER-WR Interconnection” commissioned by PGCIL’s TBCB subsidiary “Powergrid ERWR Power Transmission Ltd.” The main element of this project was a 136-ckm 400kV double-circuit line connecting PGCIL’s Jeypore substation in Odisha (ER) to the Jagdalpur substation in Chhattisgarh (WR) owned by the state power transmission utility.
During FY25, the quantum of electricity transfer from ER to WR stood at 13,271 MU, while that in the reverse direction (WR to ER) was lower at 10,188 MU. The total interregional transfer between ER and WR (both directions), at 23,459 MU, accounted for 9 per cent of the country’s total interregional transfer (between all five regional grids) of 259,937 MU in FY25.
Interregional schemes under bidding
Similar to the ER-WR interregional scheme discussed in this story, there are at least two more schemes – SR-ER and SR-WR – for which developer selection is currently underway, under the TBCB framework.
Featured photograph is for representation only